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1

Detection of Chemical Weapon Agents and Simulants Using Chemical Ionization Reaction Time-of-Flight Mass Spectrometry  

Science Journals Connector (OSTI)

Detection of Chemical Weapon Agents and Simulants Using Chemical Ionization Reaction Time-of-Flight Mass Spectrometry ... Chemical weapons were first used on a large scale in warfare in World War 1, where chlorine and sulfur mustard were used extensively. ... Many analytical methods have been developed for the detection of the active chemical constituents of chemical weapons, chemical weapon agents (CWAs), and their breakdown products in soil,5-9 groundwater,10,11 and air. ...

Rebecca L. Cordell; Kerry A. Willis; Kevin P. Wyche; Robert S. Blake; Andrew M. Ellis; Paul S. Monks

2007-09-26T23:59:59.000Z

2

Mass Spectrometry | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Microfabrication Mass Spectrometry Microscopy Molecular Science Computing NMR and EPR Spectroscopy and Diffraction Subsurface Flow and Transport Mass Spectrometry Systems...

3

Chemical crosslinking and mass spectrometry studies of the structure and dynamics of membrane proteins and receptors.  

SciTech Connect (OSTI)

Membrane proteins make up a diverse and important subset of proteins for which structural information is limited. In this study, chemical cross-linking and mass spectrometry were used to explore the structure of the G-protein-coupled photoreceptor bovine rhodopsin in the dark-state conformation. All experiments were performed in rod outer segment membranes using amino acid 'handles' in the native protein sequence and thus minimizing perturbations to the native protein structure. Cysteine and lysine residues were covalently cross-linked using commercially available reagents with a range of linker arm lengths. Following chemical digestion of cross-linked protein, cross-linked peptides were identified by accurate mass measurement using liquid chromatography-fourier transform mass spectrometry and an automated data analysis pipeline. Assignments were confirmed and, if necessary, resolved, by tandem MS. The relative reactivity of lysine residues participating in cross-links was evaluated by labeling with NHS-esters. A distinct pattern of cross-link formation within the C-terminal domain, and between loop I and the C-terminal domain, emerged. Theoretical distances based on cross-linking were compared to inter-atomic distances determined from the energy-minimized X-ray crystal structure and Monte Carlo conformational search procedures. In general, the observed cross-links can be explained by re-positioning participating side-chains without significantly altering backbone structure. One exception, between C3 16 and K325, requires backbone motion to bring the reactive atoms into sufficient proximity for cross-linking. Evidence from other studies suggests that residues around K325 for a region of high backbone mobility. These findings show that cross-linking studies can provide insight into the structural dynamics of membrane proteins in their native environment.

Haskins, William E.; Leavell, Michael D.; Lane, Pamela; Jacobsen, Richard B.; Hong, Joohee; Ayson, Marites J.; Wood, Nichole L.; Schoeniger, Joseph S.; Kruppa, Gary Hermann; Sale, Kenneth L.; Young, Malin M.; Novak, Petr

2005-03-01T23:59:59.000Z

4

EMSL - Mass Spectrometry  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

mass-spectrometry Proteomics Capabilities High resolution and mass accuracy Fourier-transform ion cyclotron resonance (FT-ICR) spectrometers, from 6 Tesla (T) to 15T and 21T in...

5

Gas Chromatography -Mass Spectrometry  

E-Print Network [OSTI]

GCMS - 1 Gas Chromatography - Mass Spectrometry GC-MS ANALYSIS OF ETHANOL AND BENZENE IN GASOLINE Last updated: June 17, 2014 #12;GCMS - 2 Gas Chromatography - Mass Spectrometry GC-MS ANALYSIS). The goal of this experiment is to separate the components in a sample of gasoline using Gas Chromatography

Nizkorodov, Sergey

6

Determination of naphthenic acids in California crudes and refinery waste waters by fluoride ion chemical ionization mass spectrometry  

SciTech Connect (OSTI)

A method based on negative ion chemical ionization mass spectrometry using fluoride (F/sup -/) ions produced from NF/sub 3/ reagent gas has been applied to the analysis of naphthenic acids in California crude oils and refinery waste waters. Since complex mixtures of naphthenic acids cannot be separated into individual components, only the determination of relative distribution of acids classified by the hydrogen deficiency was possible. The identities and relative distribution of paraffinic and mono-, di-, tri, and higher polycyclic acids were obtained from the intensities of the carboxylate (RCOO/sup -/) ions.

Dzidic, I.; Somerville, A.C.; Raia, J.C.; Hart, H.V.

1988-07-01T23:59:59.000Z

7

EMSL: Capabilities: Mass Spectrometry: Next-Generation Mass Spectrometry  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Next-Generation Mass Spectrometry Next-Generation Mass Spectrometry Additional Information Meet the Mass Spectrometry Experts Related EMSL User Projects Mass Spectrometry Tools are Applied to all Science Themes Next-Generation Mass Spectrometry Proteomics Research Resource for Integrative Biology Biological and Environmental Research - PNNL Proteomics PNNL's Biological MS Data and Software Distribution Center Mass Spectrometry brochure EMSL is committed to offering state-of-the-art instruments to its users. At a workshop in January of 2008, EMSL mass spectrometry experts joined experts from many universities, private companies, and government institutions and laboratories at a conference held at the National High Magnetic Field Laboratory in Tallahassee Florida. Workshop participants reviewed the state of the art of high-performance mass spectrometers,

8

Impurity Profiling of a Chemical Weapon Precursor for Possible Forensic Signatures by Comprehensive Two-Dimensional Gas Chromatography/Mass Spectrometry and Chemometrics  

Science Journals Connector (OSTI)

Impurity Profiling of a Chemical Weapon Precursor for Possible Forensic Signatures by Comprehensive Two-Dimensional Gas Chromatography/Mass Spectrometry and Chemometrics ... DMMP is a widely used flame retardant(6, 7) that is listed as a schedule 2 compound by the Chemical Weapons Convention (CWC) because it is a well-known CW precursor and not produced in large quantities for commercial purposes. ...

Jamin C. Hoggard; Jon H. Wahl; Robert E. Synovec; Gary M. Mong; Carlos G. Fraga

2009-12-16T23:59:59.000Z

9

Detection of Chemical/Biological Agents and Stimulants using Quadrupole Ion Trap Mass Spectrometry  

SciTech Connect (OSTI)

Detection of Chemical/Biological Agents and Simulants A new detector for chemical and biological agents is being developed for the U. S. Army under the Chemical and Biological Mass Spectrometer Block II program. The CBMS Block II is designed to optimize detection of both chemical and biological agents through the use of direct sampling inlets [I], a multi- ported sampling valve and a turbo- based vacuum system to support chemical ionization. Unit mass resolution using air as the buffer gas [2] has been obtained using this design. Software to control the instrument and to analyze the data generated from the instrument has also been newly developed. Detection of chemical agents can be accomplished. using the CBMS Block II design via one of two inlets - a l/ I 6'' stainless steel sample line -Chemical Warfare Air (CW Air) or a ground probe with enclosed capillary currently in use by the US Army - CW Ground. The Block II design is capable of both electron ionization and chemical ionization. Ethanol is being used as the Cl reagent based on a study indicating best performance for the Biological Warfare (BW) detection task (31). Data showing good signal to noise for 500 pg of methyl salicylate injected into the CW Air inlet, 50 ng of dimethylmethylphosphonate exposed to the CW Ground probe and 5 ng of methyl stearate analyzed using the pyrolyzer inlet were presented. Biological agents are sampled using a ''bio-concentrator'' unit that is designed to concentrate particles in the low micron range. Particles are collected in the bottom of a quartz pyrolyzer tube. An automated injector is being developed to deliver approximately 2 pL of a methylating reagent, tetramethylamonium- hydroxide to 'the collected particles. Pyrolysis occurs by rapid heating to ca. 55OOC. Biological agents are then characterized by their fatty acid methyl ester profiles and by other biomarkers. A library of ETOH- Cl/ pyrolysis MS data of microorganisms used for a recently published study [3] has been expanded with additional bacteria and fungi. These spectra were acquired on a Finnigan Magnum ion trap using helium buffer gas. A new database of Cl spectra of microorganisms is planned using the CBMS Block II instrument and air as the buffer gas. Using the current database, the fatty acid composition of the organisms was compared using the percentage of the ion current attributable to fatty acids. The data presented suggest promising rules for discrimination of these organisms. Strain, growth media and vegetative state do contribute to some of the distributions observed in the data. However, the data distributions observed in the current study only reflect our experience to date and do not fully represent the variability that might be expected in practice: Acquisition of MS/ MS spectra has begun (using He and air buffer gas) of the protonated molecular ion of a variety of fatty acids and for a number of ions nominally assigned as fatty acids from microorganisms. These spectra will be used to help verify fatty acid .

Harmon, S.H.; Hart, K.J.; Vass, A.A.; Wise, M.B.; Wolf, D.A.

1999-06-14T23:59:59.000Z

10

Development of New Soft Ionization Mass Spectrometry Approaches for Spatial Imaging of Complex Chemical and Biological Systems  

E-Print Network [OSTI]

world's first C60 SIMS FT-ICR MS. Unique capabilities for imaging biological samples: High mass accuracy spatial resolution (~10 µm) High spatial and mass resolution C60 secondary ion mass spectrometry (SIMS of the colony Conducted first multimodal imaging of biological materials using nano-DESI, SIMS, and matrix

11

High-Resolution Desorption Electrospray Ionization Mass Spectrometry for Chemical Characterization  

E-Print Network [OSTI]

, University of California-Irvine, Irvine, California 92697 Characterization of the chemical composition solar radiation and modifications of cloud properties.1-6 The extent of radiative forcing and cloud

Nizkorodov, Sergey

12

Quantitation by Gas Chromatography-Chemical Ionization-Mass Spectrometry of Phenylalanine Mustard in Plasma of Patients  

Science Journals Connector (OSTI)

...1980 research-article Quantification by Gas Chromatography of N,N-Di-(2-chloroethyl...addressed. A sensitive method, based on gas chromatography using a phosphorus-specific...derivatization process has been elucidated using gas chromatography-electron impact mass spectrometry...

Sharon L. Pallante; Catherine Fenselau; Robert G. Mennel; Robert B. Brundrett; Mark Appler; Neil B. Rosenshein; Michael Colvin

1980-07-01T23:59:59.000Z

13

Application of coincidence ion mass spectrometry for chemical and structural analysis at the sub-micron scale  

E-Print Network [OSTI]

Surfaces can be probed with a variant of secondary ion mass spectrometry (SIMS) where the bombardment is with a sequence of single keV projectiles, each resolved in time and space, coupled with the separate record of the secondary ions (SIs) ejected...

Balderas, Sara

2005-11-01T23:59:59.000Z

14

Xlink-Identifier: An Automated Data Analysis Platform for Confident Identifications of Chemically Cross-linked Peptides using Tandem Mass Spectrometry  

SciTech Connect (OSTI)

Chemical cross-linking combined with mass spectrometry provides a powerful method for identifying protein-protein interactions and probing the structure of protein complexes. Cross-linking is the process of covalently joining two proteins using cross-linking reagents. After proteolytic cleavage, the cross-linked peptides can be identified using tandem mass spectrometry. A number of strategies have been reported that take advantage of the high sensitivity and high resolution of modern mass spectrometers. Approaches typically include synthesis of novel cross-linking compounds and/or isotopic labelling of the cross-linkering reagent and/or protein to aid both identification and quantitation. However, these approaches have various limitations. These limitations can be overcome with a label-free approach and application of associated data analysis algorithms described in this work.

Du, Xiuxia; Chowdhury, Saiful M.; Manes, Nathan P.; Wu, Si; Mayer, M. Uljana; Adkins, Joshua N.; Anderson, Gordon A.; Smith, Richard D.

2011-03-04T23:59:59.000Z

15

MASS SPECTROMETRY WITH A VERY SMALL CYCLOTRON  

E-Print Network [OSTI]

OF CALIFORNIA mm Presented at the Argonne Symposium onHigh Energy Spectrometry, Argonne NationalLaboratory, Argonne, IL, May 11-13, 1981 MASS SPECTROMETRY

Muller, R.A.

2010-01-01T23:59:59.000Z

16

Symposium on accelerator mass spectrometry  

SciTech Connect (OSTI)

The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base.

None

1981-01-01T23:59:59.000Z

17

Instrument Series: Mass Spectrometry SPLAT II  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Mass Spectrometry Mass Spectrometry SPLAT II SPLAT II is a one-of-a-kind single particle mass spectrometer that was designed, constructed, and deployed at EMSL to allow users to precisely characterize the physical and chemical properties of nanoparticles. SPLAT II yields quantitative information on particle physical and chemical properties in the laboratory or in the field-even aboard an aircraft. In the context of EMSL's integrated problem-solving environment, the unique capabilities of SPLAT II enable vital research across a range of scientific fields. Research Applications Fundamental science - characterizing the properties and behavior of matter on the nanoscale Atmospheric chemistry - understanding the processes that control atmospheric aerosol life cycle Climate change - uncovering and helping

18

Single Cell Analysis Using Microfluidics Coupled to Ultrasensitive Mass Spectrometry  

E-Print Network [OSTI]

Single Cell Analysis Using Microfluidics Coupled to Ultrasensitive Mass Spectrometry PI Ryan Kelly is to combine microfluidic sample preparation and separations with the ultrasensitive mass spectrometry (MS without the need for chemical labeling. We will combine our expertise in the fields of microfluidics

19

Chemical Characterization of Crude Petroleum Using Nanospray Desorption Electrospray Ionization Coupled with High-Resolution Mass Spectrometry  

SciTech Connect (OSTI)

Nanospray desorption electrospray ionization (nano-DESI) combined with high-resolution mass spectrometry was used for the first time for the analysis of liquid petroleum crude oil samples. The analysis was performed in both positive and negative ionization modes using three solvents one of which (acetonitrile/toluene mixture) is commonly used in petroleomics studies while two other polar solvents (acetonitrile/water and methanol/water mixtures) are generally not compatible with petroleum characterization using mass spectrometry. The results demonstrate that nano-DESI analysis efficiently ionizes petroleum constituents soluble in a particular solvent. When acetonitrile/toluene is used as a solvent, nano-DESI generates electrospray-like spectra. In contrast, strikingly different spectra were obtained using acetonitrile/water and methanol/water. Comparison with the literature data indicates that these solvents selectively extract water-soluble constituents of the crude oil. Water-soluble compounds are predominantly observed as sodium adducts in nano-DESI spectra indicating that addition of sodium to the solvent may be a viable approach for efficient ionization of water-soluble crude oil constituents. Nano-DESI enables rapid screening of different classes of compounds in crude oil samples using solvents that are rarely used for petroleum characterization.

Eckert, Peter A.; Roach, Patrick J.; Laskin, Alexander; Laskin, Julia

2012-02-07T23:59:59.000Z

20

Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

Electrospray Ionization (ESI) is a process whereby gas phase ions are created from molecules in solution. As a solution exits a narrow tube in the presence of a strong electric field, an aerosol of charged droplets are is formed that produces gas phase ions as they it desolvates. ESI-MS comprises the creation of ions by ESI and the determination of their mass to charge ratio (m/z) by MS.

Kelly, Ryan T.; Marginean, Ioan; Tang, Keqi

2014-06-13T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Mass spectrometry: analytical capabilities and potentials  

Science Journals Connector (OSTI)

...INSULIN AND OTHER LARGE PEPTIDES, JOURNAL...MASS-SPECTROMETRY OF LARGE, FRAGILE, AND INVOLATILE...APPLICATIONS IN THE AREA OF MOLECULAR MODIFICATIONS...I-127-LABELED PLASMA DESORPTION MASS-SPECTROMETRY...PIONEER VENUS LARGE PROBE NEUTRAL MASS-SPECTROMETER...HORNING, E.C., ATMOSPHERIC-PRESSURE IONIZATION...

RG Cooks; KL Busch; GL Glish

1983-10-21T23:59:59.000Z

22

Early Days of Accelerator Mass Spectrometry  

DOE R&D Accomplishments [OSTI]

Alvarez reviews his role in the development of the tandem Van de Graaff accelerator and the technique of accelerator mass spectrometry as a technique for isotope dating. (GHT)

Alvarez, L. W.

1981-05-00T23:59:59.000Z

23

New approaches for the chemical and physical characterization of aerosols using a single particle mass spectrometry based technique  

E-Print Network [OSTI]

1-2% of the oil mass, however the calcium ion peak at m/z 40and elemental carbon (EC) peaks. The HDDV oil mass spectraoil mass spectra were characterized by an intense Ca + ion peak and

Spencer, Matthew Todd

2007-01-01T23:59:59.000Z

24

Absorption Mode FT-ICR Mass Spectrometry Imaging. | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Imaging. Absorption Mode FT-ICR Mass Spectrometry Imaging. Abstract: Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power...

25

New approaches for the chemical and physical characterization of aerosols using a single particle mass spectrometry based technique  

E-Print Network [OSTI]

1-2% of the oil mass, however the calcium ion peak at m/z 40lubricating oil is characterized by a very intense Ca + peakand elemental carbon (EC) peaks. The HDDV oil mass spectra

Spencer, Matthew Todd

2007-01-01T23:59:59.000Z

26

Thermal Decomposition of Molecules Relevant to Combustion and Chemical Vapor Deposition by Flash Pyrolysis Time-of-Flight Mass Spectrometry  

E-Print Network [OSTI]

of Small Molecules by Flash Pyrolysis, University ofwas performed using flash pyrolysis vacuum-ultraviolet time-Vapor Deposition by Flash Pyrolysis Time-of-Flight Mass

Lemieux, Jessy Mario

2013-01-01T23:59:59.000Z

27

Characterization of nonpolar lipids and steroids by using laser-induced acoustic desorption/chemical ionization, atmospheric pressure chemical ionization, and electrospray ionization mass spectrometry  

SciTech Connect (OSTI)

Laser-induced acoustic desorption (LIAD) combined with ClMn(H{sub 2}O){sup +} chemical ionization (CI) was tested for the analysis of nonpolar lipids and selected steroids in a Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR). The nonpolar lipids studied, cholesterol, 5?-cholestane, cholesta-3,5-diene, squalene, and ?-carotene, were found to solely form the desired water replacement product (adduct-H{sub 2}O) upon reaction with the ClMn(H{sub 2}O){sup +} ions. The steroids, androsterone, dehydroepiandrosterone (DHEA), estrone, estradiol, and estriol, also form abundant adduct-H{sub 2}O ions, but less abundant adduct-2H{sub 2}O ions were also observed. Neither (+)APCI nor (+)ESI can ionize the saturated hydrocarbon lipid, cholestane. APCI successfully ionizes the unsaturated hydrocarbon lipids to form exclusively the intact protonated analytes. However, it causes extensive fragmentation for cholesterol and the steroids. The worst case is cholesterol that does not produce any stable protonated molecules. On the other hand, ESI cannot ionize any of the hydrocarbon analytes, saturated or unsaturated. However, ESI can be used to protonate the oxygen-containing analytes with substantially less fragmentation than for APCI in all cases except for cholesterol and estrone. In conclusion, LIAD/ClMn(H{sub 2}O){sup +} chemical ionization is superior over APCI and ESI for the mass spectrometric characterization of underivatized nonpolar lipids and steroids.

Jin, Z.; Daiya, S.; Kenttämaa, Hilkka I.

2011-01-01T23:59:59.000Z

28

Ambient Ionization Mass Spectrometry Analysis Pertaining To Biofuel Process Development.  

E-Print Network [OSTI]

??Mass spectrometry (MS) has undergone a revolution with the introduction of a new group of desorption/ionization (DI) techniques known collectively as Ambient Ionization mass spectrometry.… (more)

Dendukuri, Sushma

2012-01-01T23:59:59.000Z

29

Secondary Ion Mass Spectrometry Imaging of Dictyostelium discoideum Aggregation Streams  

SciTech Connect (OSTI)

High resolution imaging mass spectrometry could become a valuable tool for cell and developmental biology, but both, high spatial and mass spectral resolution are needed to enable this. In this report, we employed Bi3 bombardment time-of-flight (Bi3 ToF-SIMS) and C60 bombardment Fourier transform ion cyclotron resonance secondary ion mass spectrometry (C60 FTICR-SIMS) to image Dictyostelium discoideum aggregation streams. Nearly 300 lipid species were identified from the aggregation streams. High resolution mass spectrometry imaging (FTICR-SIMS) enabled the generation of multiple molecular ion maps at the nominal mass level and provided good coverage for fatty acyls, prenol lipids, and sterol lipids. The comparison of Bi3 ToF-SIMS and C60 FTICR-SIMS suggested that while the first provides fast, high spatial resolution molecular ion images, the chemical complexity of biological samples warrants the use of high resolution analyzers for accurate ion identification.

Debord, J. Daniel; Smith, Donald F.; Anderton, Christopher R.; Heeren, Ronald M.; Pasa-Tolic, Ljiljana; Gomer, Richard H.; Fernandez-Lima, Francisco A.

2014-06-09T23:59:59.000Z

30

Simultaneous determination of nine trace mono- and di-chlorophenols in water by ion chromatography atmospheric pressure chemical ionization mass spectrometry  

Science Journals Connector (OSTI)

A novel analytical method was proposed for the rapidly simultaneous determination of nine mono-chlorophenols (MCPs) and di-chlorophenols (DCPs) in water samples using eluent generator ion chromatography (IC) coupled with an atmospheric pressure chemical ionization mass spectrometry (APCI-MS) in the negative mode. The IC separation was carried out on an IonPac® AS11 analytical column (250 mm × 4.0 mm) using gradient KOH containing 15% acetonitrile as organic modifier at a constant flow rate of 1.0 mL/min. The molecular ions m/z [M ? H]? 127 and 161 were selected for the quantification in selected ion monitoring (SIM) mode for \\{MCPs\\} and DCPs, respectively. The average recoveries were between 80.6% and 92.6%. Within-day and day-to-day relative standard deviations were less than 12.1% and 13.3%, respectively. The method allowed the nine objective compounds in water samples to be determined at ?g/L levels. It was confirmed that this method could be used in routine analysis.

Micong Jin; Yiwen Yang

2006-01-01T23:59:59.000Z

31

High-Performance Mass Spectrometry Facility  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

HPMSF Overview HPMSF Overview Section 2-4-1 High-Performance Mass Spectrometry Facility The High-Performance Mass Spectrometry Facility (HPMSF) provides state-of-the-art mass spectrometry (MS) and separations instrumentation that has been refined for leading-edge analysis of biological problems with a primary emphasis on proteomics. Challenging research in proteomics, cell signaling, cellular molecular machines, and high-molecular weight systems receive the highest priority for access to the facility. Current research activities in the HPMSF include proteomic analyses of whole cell lysates, analyses of organic macro-molecules and protein complexes, quantification using isotopically labeled growth media, targeted proteomics analyses of subcellular fractions, and nucleic acid analysis of

32

High performance ²?²Cf plasma desorption mass spectrometry  

E-Print Network [OSTI]

ABSTRACT . ACKNOWLEDGEMENT TABLE OF CONTENTS . tv LIST OF TABLES LIST OF FIGURES C~R I. INTRODUCTION tx xt A. A General Overview . 1. Particle-Induced Desorption 2. The Application of Cf PDMS in Analytical Chemistry 3. Time-of-Flight Mass... INTRODUCTION The method of 'Cf plasma desorption mass spectrometry (PDMS) is a mass spectrometric method pioneered in 1974 by Macfarlane and co-workers (1) at Texas A&M University. This method uses fission fragments (highly energetic atomic ions...

McIntire, Thomas Shane

1991-01-01T23:59:59.000Z

33

A Brief History of Mass Spectrometry  

Science Journals Connector (OSTI)

A Brief History of Mass Spectrometry ... More complete histories of MS are available both in print (e.g., Ref. 1) and on the web. ... He began his academic career as an electrical engineer but, because of the paucity of engineering courses available at the time, eventually turned to physics for his graduate work at the Minnesota. ...

Jennifer Griffiths

2008-07-31T23:59:59.000Z

34

Correlation of rocket propulsion fuel properties with chemical composition using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry followed by partial least squares regression analysis  

SciTech Connect (OSTI)

There is an increased need to more fully assess and control the composition of kerosene based rocket propulsion fuels, namely RP-1 and RP-2. In particular, it is crucial to be able to make better quantitative connections between the following three attributes: (a) fuel performance, (b) fuel properties (flash point, density, kinematic viscosity, net heat of combustion, hydrogen content, etc) and (c) the chemical composition of a given fuel (i.e., specific chemical compounds and compound classes present as a result of feedstock blending and processing). Indeed, recent efforts in predicting fuel performance through modeling put greater emphasis on detailed and accurate fuel properties and fuel compositional information. In this regard, advanced distillation curve (ADC) metrology provides improved data relative to classical boiling point and volatility curve techniques. Using ADC metrology, data obtained from RP-1 and RP-2 fuels provides compositional variation information that is directly relevant to predictive modeling of fuel performance. Often, in such studies, one-dimensional gas chromatography (GC) combined with mass spectrometry (MS) is typically employed to provide chemical composition information. Building on approaches using GC-MS, but to glean substantially more chemical composition information from these complex fuels, we have recently studied the use of comprehensive two dimensional gas chromatography combined with time-of-flight mass spectrometry (GC × GC - TOFMS) to provide chemical composition data that is significantly richer than that provided by GC-MS methods. In this report, by applying multivariate data analysis techniques, referred to as chemometrics, we are able to readily model (correlate) the chemical compositional information from RP-1 and RP-2 fuels provided using GC × GC - TOFMS, to the fuel property information such as that provided by the ADC method and other specification properties. We anticipate that this new chemical analysis strategy will have broad implications for the development of high fidelity composition-property models, leading to an optimized approach to fuel formulation and specification for advanced engine cycles.

Kehimkar, Benjamin; Hoggard, Jamin C.; Marney, Luke C.; Billingsley, Matthew; Fraga, Carlos G.; Bruno, Thomas J.; Synovec, Robert E.

2014-01-31T23:59:59.000Z

35

Monolithic multinozzle emitters for nanoelectrospray mass spectrometry  

DOE Patents [OSTI]

Novel and significantly simplified procedures for fabrication of fully integrated nanoelectrospray emitters have been described. For nanofabricated monolithic multinozzle emitters (NM.sup.2 emitters), a bottom up approach using silicon nanowires on a silicon sliver is used. For microfabricated monolithic multinozzle emitters (M.sup.3 emitters), a top down approach using MEMS techniques on silicon wafers is used. The emitters have performance comparable to that of commercially-available silica capillary emitters for nanoelectrospray mass spectrometry.

Wang, Daojing (Daly City, CA); Yang, Peidong (Kensington, CA); Kim, Woong (Seoul, KR); Fan, Rong (Pasadena, CA)

2011-09-20T23:59:59.000Z

36

Electrospray Ionization Mass Spectrometry of hexanitrohexaazaisowurtzitane (CL-20)  

SciTech Connect (OSTI)

Hexanitrohexaazaisowurtzitane, (C6H6N12O12, MW 438) {CL-20}, is a high-energy propellent that has been recently developed and successfully tested (Nielsen et al. 1998). CL-20 releases more energy on ignition and is more stable to accidental detonation than currently used energetic materials. It is expected to replace many of the energetic materials currently being used by the Department of Defense (DoD). The EPA method 8330 (EPA 1997) for the analysis of explosives and metabolites in soils calls for the use of UV/Vis detection. High performance liquid chromatography has been used to quantify CL-20 and precursor concentration (Bazaki et al. 1998`) at relatively high concentrations. Fourier transform infrared (FTIR) spectroscopy has been used to identify different crystal forms of CL-20 (4 isomers; Kim et al. 1998). Campbell et al. (1997) utilized particle beam mass spectrometry for the analysis of enzymatic degradation of explosives. Introduction and recent improvements of ionization techniques such as electrospray (ES) have allowed the mass spectrometer to become more widely used in liquid chromatography. Schilling(1996) also examined explosive components and metabolites using electrospray (ES) and atmospheric pressure chemical ionization (APCI) liquid chromatography/mass spectrometry (LC/MS). Schilling’s results showed that compared to thermospray LC/MS, APCI and ES were more sensitive than thermospray by at least an order of magnitude. 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), 10 nitroso-RDX metabolites, and other munitions in ground water have been analyzed using solid phase extraction and isotope dilution liquid chromatography-APCI mass spectrometry (Cassada et al. 1999). The method detection limits indicate that nitramine and nitroaromatic compounds can be routinely determined in ground water samples using electrospray LC/MS with concentration techniques utilizing solid-phase extraction. Miller et al. (1996) studied nitrated explosives with mobile phase additives to enhance the ESI intensities and spectral consistencies. Several of the explosives gave nitrate adduct ions in the negative mode with ammonium nitrate as the mobile phase. The nitramines RDX and 1,3,5,7-tetranitro-1,3,5,7 tetraazacyclooctane (HMX) showed the greatest enhancement in response of the explosives. Ammonium nitrate was used as the mobile phase and made it possible to obtain consistent and interpretable LC/MS spectra at the nanogram level. Campbell et al. (1999), Shi et al. (2000), and Goheen et al. (1999) utilized electrospray ionization mass spectrometry for the identification of degradation products of explosives. Yinon et al. (1997) used ESI and tandem mass spectrometry collision-induced dissociation to examine several nitramine compounds including trinitrotolutene (TNT), RDX, and pentaerythritol tetranitrate (PETN). The results indicate that explosives can be detected in the negative ion mode and characterized by various adduct ions. As an example, for nitroglycerin, the major adduct ion observed was (M+ONO2)-. In addition, Harvey et al. (1992) have used direct probe mass spectrometry for the analysis of degradation products of tetryl and its transformation products in soil. The negative ion electrospray mass spectrum of CL-20 is reported here. The major adduct ions observed under negative ion conditions were (M+Cl)- at m/z 473 and (M+ONO2) – at m/z 500. In addition, the results of mass spectrometry/mass spectrometry studies are also discussed.

Campbell, James A.; Szecsody, Jim E.; Devary, Brooks J.; Valenzuela, Blandina R.

2007-09-03T23:59:59.000Z

37

High-Resolution Electrospray Ionization Mass Spectrometry Analysis...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Mass Spectrometry Analysis of Water- Soluble Organic Aerosols Collected with a Particle Abstract: This work demonstrates the utility of a particle-into-liquid sampler (PILS) a...

38

In situ secondary ion mass spectrometry analysis  

SciTech Connect (OSTI)

The direct detection of tributyl phosphate (TBP) on rocks using molecular beam surface analysis [MBSA or in situ secondary ion mass spectrometry (SIMS)] is demonstrated. Quantities as low as 250 ng were detected on basalt and sandstone with little or no sample preparation. Detection of TBP on soil has proven to be more problematic and requires further study. Ethylenediaminetetraacetic acid (EDTA) is more difficult to detect because it is very reactive with surfaces of interest. Nevertheless, it is possible to detect EDTA if the acidity of the surface is controlled. The detection of EDTA-metal complexes is currently an open question, but evidence is presented for the detection of ions arising from a EDTA-lead complex. Carboxylic acids (i.e., citric, ascorbic, malic, succinic, malonic, and oxalic) give characteristic SIM spectra, but their detection on sample surfaces awaits evaluation.

Groenewold, G.S.; Applehans, A.D.; Ingram, J.C.; Delmore, J.E.; Dahl, D.A.

1993-01-01T23:59:59.000Z

39

Solid-Phase Extraction Combined with High-Performance Liquid Chromatography?Atmospheric Pressure Chemical Ionization?Mass Spectrometry Analysis of Pesticides in Water:? Method Performance and Application in a Reconnaissance Survey of Residues in Drinking Water in Greater Cairo, Egypt  

Science Journals Connector (OSTI)

Solid-Phase Extraction Combined with High-Performance Liquid Chromatography?Atmospheric Pressure Chemical Ionization?Mass Spectrometry Analysis of Pesticides in Water:? Method Performance and Application in a Reconnaissance Survey of Residues in Drinking Water in Greater Cairo, Egypt ... Each shipment, which included 24 cartridges, weighed <454 g and cost approximately 200 Egyptian pounds ($40 U.S.). ...

Thomas L. Potter; Mahmoud A. Mohamed; Hannah Ali

2006-12-22T23:59:59.000Z

40

A Validated Liquid Chromatography-Atmospheric Pressure Chemical Ionization-Tandem Mass Spectrometry Method for Quantitation of Cocaine and Benzoylecgonine in Human Plasma  

Science Journals Connector (OSTI)

......Chromatography-Atmospheric Pressure Chemical...Benzoylecgonine in Human Plasma Shen-Nan Lin 1...chromatography-atmospheric pressure chemical...benzoylecgonine in human plasma. | In order to...ValidatedLiquidChromatography-Atmospheric PressureChemicalIonization...benzoylecgonine in human plasma.Cocaine-dsand......

Shen-Nan Lin; David E. Moody; George E. Bigelow; Rodger L. Foltz

2001-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Evaluation of histone sequence and modifications by electrospray ionization mass spectrometry and tandem mass spectrometry  

SciTech Connect (OSTI)

The histones, together with other specialized proteins and DNA, form the extraordinarily complex structure of chromatin. Electrospray ionization (ESI) permits the promotion of such protein species into the gas phase as intact, multiply charged molecular species. Mass spectrometry (MS), using a linear quadrupole mass filter, permits measurement of the relative molecular mass of these intact species with precision and accuracy. The latter are sufficient to evaluate variations in the primary structure of the histones and the type and extent of the natural and induced multiple covalent modifications. The locations of modifications are revealed by tandem mass spectrometry using tandem linear quadrupole or ion trap instruments on the intact species or the modified peptides derived by selective proteolysis. Experiments in applying this technique to histones from K562, a human-derived cell line, have demonstrated variations in the profile of modification through the normal cell cycle and in the presence of agents that inhibit enzymes responsible for reversal of the modification. The authors are currently testing the hypothesis that ESI-MS will permit the sensitive and selective identification of insult-induced modifications, distinguishing them from natural cell-cycle changes. This will be possible because ESI-MS reveals the full details of the profile of multiple posttranslational modifications of histones.

Edmonds, C.G.; Loo, J.A.; Smith, R.D.; Fuciarelli, A.F.; Thrall, B.D.; Morris, J.E.; Springer, D.L. (Pacific Northwest Lab., Richland, WA (United States))

1993-01-01T23:59:59.000Z

42

High Mass Accuracy and High Mass Resolving Power FT-ICR Secondary Ion Mass Spectrometry for Biological Tissue Imaging  

SciTech Connect (OSTI)

Biological tissue imaging by secondary ion mass spectrometry has seen rapid development with the commercial availability of polyatomic primary ion sources. Endogenous lipids and other small bio-molecules can now be routinely mapped on the micrometer scale. Such experiments are typically performed on time-of-flight mass spectrometers for high sensitivity and high repetition rate imaging. However, such mass analyzers lack the mass resolving power to ensure separation of isobaric ions and the mass accuracy for exact mass elemental formula assignment. We have recently reported a secondary ion mass spectrometer with the combination of a C60 primary ion gun with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) for high mass resolving power, high mass measurement accuracy and tandem mass spectrometry capabilities. In this work, high specificity and high sensitivity secondary ion FT-ICR MS was applied to chemical imaging of biological tissue. An entire rat brain tissue was measured with 150 ?m spatial resolution (75 ?m primary ion spot size) with mass resolving power (m/?m50%) of 67,500 (at m/z 750) and root-mean-square measurement accuracy less than two parts-per-million for intact phospholipids, small molecules and fragments. For the first time, ultra-high mass resolving power SIMS has been demonstrated, with m/?m50% > 3,000,000. Higher spatial resolution capabilities of the platform were tested at a spatial resolution of 20 ?m. The results represent order of magnitude improvements in mass resolving power and mass measurement accuracy for SIMS imaging and the promise of the platform for ultra-high mass resolving power and high spatial resolution imaging.

Smith, Donald F.; Kiss, Andras; Leach, Franklin E.; Robinson, Errol W.; Pasa-Tolic, Ljiljana; Heeren, Ronald M.

2013-07-01T23:59:59.000Z

43

E-Print Network 3.0 - aerosol mass spectrometry Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

used in health effects studies by aerosol mass spectrometry Wingen, L... and heats of sublimation using atmospheric solids analysis probe mass spectrometry (ASAP-MS) Bruns E......

44

Analysis of perchlorate in groundwater by electrospray ionization mass spectrometry/mass spectrometry  

SciTech Connect (OSTI)

An electrospray ionization mass spectrometry/mass spectrometry (ESI/MS/MS) method was developed to measure part-per-billion ({micro}g/L) concentrations of perchlorate in groundwater. Selective and sensitive perchlorate detection was achieved by operating the mass spectrometer in the negative ionization mode and by using MS/MS to monitor the CIO{sub 4}{sup {minus}} to ClO{sub 3}{sup {minus}} transition. The method of standard additions was used to address the considerable signal suppression caused by anions that are typically present in groundwater, such as bicarbonate and sulfate. ESI-MS/MS analysis was rapid, accurate, reproducible, and provided a detection limit of 0.5 {micro}g/L perchlorate in groundwater. Accuracy and precision of the ESI/MS/MS method were assessed by analyzing performance evaluation samples in a groundwater matrix and by comparing ion chromatography (IC) and ESI/MS/MS results for local groundwater samples. Results for the performance evaluation samples differed from the certified values by 4--13%, and precision ranged from 3 to 10% (relative standard deviation). The IC and ESI/MS/MS results were statistically indistinguishable for perchlorate concentrations above the detection limits of both methods.

Koester, C.J.; Beller, H.R.; Halden, R.U.

2000-05-01T23:59:59.000Z

45

Laser mass spectrometry for DNA sequencing, disease diagnosis, and fingerprinting  

SciTech Connect (OSTI)

Since laser mass spectrometry has the potential for achieving very fast DNA analysis, the authors recently applied it to DNA sequencing, DNA typing for fingerprinting, and DNA screening for disease diagnosis. Two different approaches for sequencing DNA have been successfully demonstrated. One is to sequence DNA with DNA ladders produced from Snager`s enzymatic method. The other is to do direct sequencing without DNA ladders. The need for quick DNA typing for identification purposes is critical for forensic application. The preliminary results indicate laser mass spectrometry can possibly be used for rapid DNA fingerprinting applications at a much lower cost than gel electrophoresis. Population screening for certain genetic disease can be a very efficient step to reducing medical costs through prevention. Since laser mass spectrometry can provide very fast DNA analysis, the authors applied laser mass spectrometry to disease diagnosis. Clinical samples with both base deletion and point mutation have been tested with complete success.

Winston Chen, C.H.; Taranenko, N.I.; Zhu, Y.F.; Chung, C.N.; Allman, S.L.

1997-03-01T23:59:59.000Z

46

Applications of Secondary Ion Mass Spectrometry (SIMS) in Materials Science  

Science Journals Connector (OSTI)

Secondary Ion Mass Spectrometry (SIMS) is a mature surface analysis technique with ... Materials Science. In this review article the SIMS process is described, the fundamental SIMS equations are derived and the m...

D. S. McPhail

2006-02-01T23:59:59.000Z

47

Oil-Spill Identification by Gas Chromatography-Mass Spectrometry  

Science Journals Connector (OSTI)

...May-June research-article Articles Oil-Spill Identification by Gas Chromatography-Mass Spectrometry...the identification of a contaminant caused by the spilling of oil or oil products in water. A capillary gas chromatography (CGC......

A. Pavlova; D. Papazova

48

Subcellular analysis by laser ablation electrospray ionization mass spectrometry  

DOE Patents [OSTI]

In various embodiments, a method of laser ablation electrospray ionization mass spectrometry (LAESI-MS) may generally comprise micro-dissecting a cell comprising at least one of a cell wall and a cell membrane to expose at least one subcellular component therein, ablating the at least one subcellular component by an infrared laser pulse to form an ablation plume, intercepting the ablation plume by an electrospray plume to form ions, and detecting the ions by mass spectrometry.

Vertes, Akos; Stolee, Jessica A; Shrestha, Bindesh

2014-12-02T23:59:59.000Z

49

Direct analysis of samples by mass spectrometry: From elements to bio-molecules using laser ablation inductively couple plasma mass spectrometry and laser desorption/ionization mass spectrometry  

SciTech Connect (OSTI)

Mass spectrometric methods that are able to analyze solid samples or biological materials with little or no sample preparation are invaluable to science as well as society. Fundamental research that has discovered experimental and instrumental parameters that inhibit fractionation effects that occur during the quantification of elemental species in solid samples by laser ablation inductively coupled plasma mass spectrometry is described. Research that determines the effectiveness of novel laser desorption/ionization mass spectrometric methods for the molecular analysis of biological tissues at atmospheric pressure and at high spatial resolution is also described. A spatial resolution is achieved that is able to analyze samples at the single cell level.

Perdian, David C.

2009-08-19T23:59:59.000Z

50

Matrix Effects in Biological Mass Spectrometry Imaging: Identification and Compensation  

SciTech Connect (OSTI)

Matrix effects in mass spectrometry imaging (MSI) may affect the observed molecular distribution in chemical and biological systems. In this study, we introduce an experimental approach that efficiently compensates for matrix effects in nanospray desorption electrospray ionization (nano-DESI) MSI without introducing any complexity into the experimental protocol. We demonstrate compensation for matrix effects in nano-DESI MSI of phosphatidylcholine (PC) in normal and ischemic mouse brain tissue by doping the nano-DESI solvent with PC standards. Specifically, we use mouse brain tissue of a middle cerebral artery occlusion (MCAO) stroke model with an ischemic region localized to one hemisphere of the brain. Due to similar suppression in ionization of endogenous PC molecules extracted from the tissue and PC standards added to the solvent, matrix effects are eliminated by normalizing the intensity of the sodium and potassium adducts of endogenous PC to the intensity of the corresponding adduct of the PC standard. This approach efficiently compensates for signal variations resulting from differences in the local concentrations of sodium and potassium in tissue sections and from the complexity of the extracted analyte mixture derived from local variations in molecular composition.

Lanekoff, Ingela T.; Stevens, Susan; Stenzel-Poore, Mary; Laskin, Julia

2014-07-21T23:59:59.000Z

51

Coming to a hospital near you: mass spectrometry imaging  

SciTech Connect (OSTI)

Berkeley Lab's Ben Bowen discusses "Coming to a hospital near you: mass spectrometry imaging" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas. Go here to watch the entire event with all 8 speakers.

Bowen, Ben

2013-10-31T23:59:59.000Z

52

Coming to a hospital near you: mass spectrometry imaging  

ScienceCinema (OSTI)

Berkeley Lab's Ben Bowen discusses "Coming to a hospital near you: mass spectrometry imaging" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas. Go here to watch the entire event with all 8 speakers.

Bowen, Ben

2014-06-24T23:59:59.000Z

53

Transition of Iodine Analysis to Accelerator Mass Spectrometry  

SciTech Connect (OSTI)

This NA 22 funded research project investigated the transition of iodine isotopic analyses from thermal ionization mass spectrometry (TIMS) to an accelerator mass spectrometry (AMS) system. Previous work (Fiscal Year 2010) had demonstrated comparable data from TIMS and AMS. With AMS providing comparable data with improved background levels and vastly superior sample throughput, improvement in the sample extraction from environmental sample matrices was needed to bring sample preparation throughput closer to the operation level of the instrument. Previous research used an extraction chemistry that was not optimized for yield or refined for reduced labor to prove the principle. This research was done to find an extraction with better yield using less labor per sample to produce a sample ready for the AMS instrument. An extraction method using tetramethyl ammonium hydroxide (TMAH) was developed for removal of iodine species from high volume air filters. The TMAH with gentle heating was superior to the following three extraction methods: ammonium hydroxide aided by sonication, acidic and basic extraction aided by microwave, and ethanol mixed with sodium hydroxide. Taking the iodine from the extraction solvent to being ready for AMS analysis was accomplished by a direct precipitation, as well as, using silver wool to harvest the iodine from the TMAH. Portions of the same filters processed in FY 2010 were processed again with the improved extraction scheme followed by successful analysis by AMS at the Swiss Federal Institute of Technology. The data favorably matched the data obtained in 2010. The time required for analysis has been reduced over the aqueous extraction/AMS approach developed in FY 2010. For a hypothetical batch of 30 samples, the AMS methodology is about 10 times faster than the traditional gas phase chemistry and TIMS analysis. As an additional benefit, background levels for the AMS method are about 1000 times lower than TIMS. This results from the fundamental mechanisms of ionization in the AMS system and which produces a beneficial cleanup of molecular interferences. Continued clean operation of the extraction process was demonstrated through blank analysis included with all sample sets analyzed. INL work showed improvement on the first year’s demonstration of AMS vs. TIMS. An improved extraction of high volume air filters followed by isotopic analysis by AMS, can be used successfully to make iodine measurements with results comparable to those obtained by filter combustion and TIMS analysis. More progress on the conversion from an extract solution to an AMS sample ready for analysis is still needed. Although the preparation scheme through AMS is already at a higher performing thoughput than TIMS, the chemical preparation cannot match the instrument capability for number of samples per day without further development.

M. L. Adamic; J. E. Olson; D. D. Jenson; J. G. Eisenmenger; M. G. Watrous

2012-09-01T23:59:59.000Z

54

Mass spectrometry: analytical capabilities and potentials  

Science Journals Connector (OSTI)

...inductively ~hlorodibencoupled plasma (ICP) mass spectrome-a coal...design have long been used for atmospheric and plan-etary exploration...digitization rates of 30 to 100 kHz for GC-IR and 100 kHz to 5 MHz for GC-MS) and the equally...

RG Cooks; KL Busch; GL Glish

1983-10-21T23:59:59.000Z

55

Mass spectrometry of proteins of known mass Andrew D. Miranker*  

E-Print Network [OSTI]

deter- mination has two significant advantages. First, the mass accuracy under these conditions to the orifice of the mass analyzer. As a result, there is a local separation of charges at the tip

Miranker, Andrew

56

Determination of boron isotope ratios in geological materials by inductively coupled plasma mass spectrometry  

Science Journals Connector (OSTI)

Determination of boron isotope ratios in geological materials by inductively coupled plasma mass spectrometry ... Isotope dilution analysis using flow injection inductively coupled plasma mass spectrometry was applied to determine low boron contents in iron and steel samples. ...

D. Conrad Gregoire

1987-10-01T23:59:59.000Z

57

Tandem Mass Spectrometry identifies many mouse brain O-GlcNAcylated...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Tandem Mass Spectrometry identifies many mouse brain O-GlcNAcylated proteins including EGF domain-specific O-GlcNAc transferase Tandem Mass Spectrometry identifies many mouse brain...

58

Observing the invisible through imaging mass spectrometry, a window into the metabolic exchange patterns of microbes  

E-Print Network [OSTI]

Observing the invisible through imaging mass spectrometry, a window into the metabolic exchange this article as: Gonzalez DJ., et al, Observing the invisible through imaging mass spectrometry, a window

Nizet, Victor

59

Single Cell Analysis Using Microfluidics Coupled to Ultrasensitive Mass Spectrometry  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cell Analysis Using Microfluidics Coupled to Ultrasensitive Mass Cell Analysis Using Microfluidics Coupled to Ultrasensitive Mass Spectrometry PI Ryan Kelly, EMSL Co-investigators Xuefei Sun, FCSD, Bryan Linggi, EMSL, Keqi Tang, FCSD Proteomics and metabolomics measurements in their present form require large populations of cells and thus average over and obscure important heterogeneity that is present even in clonal populations cultivated under highly controlled conditions. For "real world" samples, this means that important but rare events go undetected, and the effects of stochastic expression and the microenvironment are blurred. The objective of this proposal is to combine microfluidic sample preparation and separations with the ultrasensitive mass spectrometry (MS) capability located in the EMSL to extend proteomic and

60

SIMS—A precursor and partner to contemporary mass spectrometry  

Science Journals Connector (OSTI)

Abstract Significant events driving the development of SIMS over the last 50 years are reviewed. The discussion includes recollections of dynamic and static SIMS from the 1970s, of the emergence of TOF–SIMS during the 1980s and of the incorporation of cluster ion bombardment during most recent times. Advances in theoretical understanding of the sputtering phenomenon and of the ionization process that accompanied these advances are also included. Many early discoveries were focused upon the stimulated desorption of organic and bioorganic molecules, first via static SIMS and next via fast atom bombardment, that were important precursor experiments to modern day mass spectrometry. Today, submicron molecule-specific imaging and molecular depth profiling represent unique aspects of SIMS experiments. Developments that led to the optimization of these modalities are also emphasized in the review. In general, the characteristics of SIMS that make it a contemporary partner to modern day mass spectrometry are highlighted.

John C. Vickerman; Nicholas Winograd

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Chip-Scale Quadrupole Mass Filters for Portable Mass Spectrometry  

E-Print Network [OSTI]

We report the design, fabrication, and characterization of a new class of chip-scale quadrupole mass filter (QMF). The devices are completely batch fabricated using a wafer-scale process that integrates the quadrupole ...

Cheung, Kerry

62

Isoelectric Trapping and Mass Spectrometry: Tools for Proteomics  

E-Print Network [OSTI]

ISOELECTRIC TRAPPING AND MASS SPECTROMETRY: TOOLS FOR PROTEOMICS A Dissertation by STEPHANIE MARIE COLOGNA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, David H. Russell Committee Members, Paul S. Cremer Arul Jayaraman Gyula Vigh Head of Department, David H...

Cologna, Stephanie Marie

2012-02-14T23:59:59.000Z

63

JOURNAL OF MASS SPECTROMETRY J. Mass Spectrom. 2003; 38: 277282  

E-Print Network [OSTI]

tandem mass spectrom- etry even isomerizations such as isoaspartate formation are detectable.3 Low-energy, nuclear and endosomal morphology, a defect in fluid-phase uptake and an impairment in normal cytokinesis.1.02 derived from acrylamide-modified peptides.8 These fragmentation reactions can be utilized for the spe-

Manstein, Dietmar J.

64

Fourier transform mass spectrometry of high-mass biomolecules  

SciTech Connect (OSTI)

In this report the authors present an overview of the use of FTMS for the analysis of large biomolecules, with emphasis on recent developments in coupling ESI and MALDI with FTMS. A simple description of the principles of FTMS operation and experimental factors that are relevant to the examination of large molecules are also presented. The examples represent state-of-the-art capabilities of FTMS. On the basis of early reports, it is apparent that the applications of FTMS for the analysis of biopolymers will expand rapidly in the near future. Although many different types of mass analyzers are compatible with FAB, ESI, and MALDI, FTMS has exhibited particular potential for high sensitivity, accurate mass measurement, high-mass resolution, and structural characterization of large biopolymers. The recent results obtained with both ESI-FTMS and MALDI-FTMS are very exciting with respect to both fundamental advances in the capabilities of FTMS and potential applications in the biochemical laboratory. 63 refs., 6 figs., 1 tab.

Buchanan, M.V.; Hettich, R.L. (Oak Ridge National Lab., TN (United States))

1993-03-01T23:59:59.000Z

65

A Dual Platform for Selective Analyte Enrichment and Ionization in Mass Spectrometry Using Aptamer-Conjugated Graphene Oxide  

E-Print Network [OSTI]

A Dual Platform for Selective Analyte Enrichment and Ionization in Mass Spectrometry Using Aptamer/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan UniVersity, Changsha and detection platform for analytes from complex biological media. We have shown that cocaine and adenosine can

Tan, Weihong

66

RAPID DETERMINATION OF ACTINIDES IN URINE BY INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY: A HYBRID APPROACH  

SciTech Connect (OSTI)

A new rapid separation method that allows separation and preconcentration of actinides in urine samples was developed for the measurement of longer lived actinides by inductively coupled plasma mass spectrometry (ICP-MS) and short-lived actinides by alpha spectrometry; a hybrid approach. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration, if required, is performed using a streamlined calcium phosphate precipitation. Similar technology has been applied to separate actinides prior to measurement by alpha spectrometry, but this new method has been developed with elution reagents now compatible with ICP-MS as well. Purified solutions are split between ICP-MS and alpha spectrometry so that long- and short-lived actinide isotopes can be measured successfully. The method allows for simultaneous extraction of 24 samples (including QC samples) in less than 3 h. Simultaneous sample preparation can offer significant time savings over sequential sample preparation. For example, sequential sample preparation of 24 samples taking just 15 min each requires 6 h to complete. The simplicity and speed of this new method makes it attractive for radiological emergency response. If preconcentration is applied, the method is applicable to larger sample aliquots for occupational exposures as well. The chemical recoveries are typically greater than 90%, in contrast to other reported methods using flow injection separation techniques for urine samples where plutonium yields were 70-80%. This method allows measurement of both long-lived and short-lived actinide isotopes. 239Pu, 242Pu, 237Np, 243Am, 234U, 235U and 238U were measured by ICP-MS, while 236Pu, 238Pu, 239Pu, 241Am, 243Am and 244Cm were measured by alpha spectrometry. The method can also be adapted so that the separation of uranium isotopes for assay is not required, if uranium assay by direct dilution of the urine sample is preferred instead. Multiple vacuum box locations may be set-up to supply several ICP-MS units with purified sample fractions such that a high sample throughput may be achieved, while still allowing for rapid measurement of short-lived actinides by alpha spectrometry.

Maxwell, S.; Jones, V.

2009-05-27T23:59:59.000Z

67

Quantitative Mapping of 4?-Iododeoxyrubicin in Metastatic Squamous Cell Carcinoma by Secondary Ion Mass Spectrometry (SIMS) Microscopy  

Science Journals Connector (OSTI)

...Carcinoma by Secondary Ion Mass Spectrometry (SIMS) Microscopy 1 1 This work was supported...cellcarcinoma by secondary ion mass spectrometry (SIMS) microscopy. | Secondary ion mass spectrometry...Carcinoma by Secondary Ion Mass Spectrometry (SIMS) Microscopy1 Philippe Fragu,2 Jerzy...

Philippe Fragu; Jerzy Klijanienko; Daniel Gandia; Sylvain Halpern; Jean-Pierre Armand

1992-02-15T23:59:59.000Z

68

Future Directions of Structural Mass Spectrometry using Hydroxyl Radical Footprinting  

SciTech Connect (OSTI)

Hydroxyl radical protein footprinting coupled to mass spectrometry has been developed over the last decade and has matured to a powerful method for analyzing protein structure and dynamics. It has been successfully applied in the analysis of protein structure, protein folding, protein dynamics, and protein-protein and protein-DNA interactions. Using synchrotron radiolysis, exposure of proteins to a 'white' X-ray beam for milliseconds provides sufficient oxidative modification to surface amino acid side chains, which can be easily detected and quantified by mass spectrometry. Thus, conformational changes in proteins or protein complexes can be examined using a time-resolved approach, which would be a valuable method for the study of macromolecular dynamics. In this review, we describe a new application of hydroxyl radical protein footprinting to probe the time evolution of the calcium-dependent conformational changes of gelsolin on the millisecond timescale. The data suggest a cooperative transition as multiple sites in different molecular subdomains have similar rates of conformational change. These findings demonstrate that time-resolved protein footprinting is suitable for studies of protein dynamics that occur over periods ranging from milliseconds to seconds. In this review, we also show how the structural resolution and sensitivity of the technology can be improved as well. The hydroxyl radical varies in its reactivity to different side chains by over two orders of magnitude, thus oxidation of amino acid side chains of lower reactivity are more rarely observed in such experiments. Here we demonstrate that the selected reaction monitoring (SRM)-based method can be utilized for quantification of oxidized species, improving the signal-to-noise ratio. This expansion of the set of oxidized residues of lower reactivity will improve the overall structural resolution of the technique. This approach is also suggested as a basis for developing hypothesis-driven structural mass spectrometry experiments.

J Kiselar; M Chance

2011-12-31T23:59:59.000Z

69

Development of A Cryogenic Drift Cell Spectrometer and Methods for Improving the Analytical Figures of Merit for Ion Mobility-Mass Spectrometry Analysis  

E-Print Network [OSTI]

A cryogenic (325-80 K) ion mobility-mass spectrometer was designed and constructed in order to improve the analytical figures-of-merit for the chemical analysis of small mass analytes using ion mobility-mass spectrometry. The instrument incorporates...

May, Jody C.

2010-10-12T23:59:59.000Z

70

New developments in biochemical mass spectrometry: Electrospray ionization  

SciTech Connect (OSTI)

The principles, development, and recent application of electrospray ionization-mass spectrometry (ESI-MS) to biological compounds are reviewed. ESI-MS methods now allow determination of accurate molecular weights for proteins extending to over 50,000, and in some cases well over 100,000. Similar capabilities are being developed for oligonucleotides. The instrumentation used for ESI-MS is briefly described and it is shown that, although ionization efficiency appears to be uniformly high, detector sensitivity may be directly correlated with molecular weight. The use of tandem mass spectrometry (e.g., MS/MS) for extending collision-induced dissociation (CID) methods to the structural studies of large molecules is described. For example, effective CID of various albumin species (molecular weight {approximately}66,000) can be obtained, far larger than obtainable for singly charged molecular ions. The combination of capillary electrophoresis, in both free solution zone electrophoresis and isotachophoresis formats, as well as microcolumn liquid chromatography with ESI-MS, provides the capability for on-line separation and analysis of subpicomole quantities of proteins. These and other new developments related to ESI-MS are illustrated by a range of examples. Fundamental considerations suggest even more impressive developments may be anticipated related to detection sensitivity and methods for obtaining structural information.

Smith, R.D.; Loo, J.A.; Edmonds, C.G.; Barinaga, C.J.; Udseth, H.R. (Pacific Northwest Laboratory, Richland, WA (USA))

1990-05-01T23:59:59.000Z

71

Analysis of hazardous biological material by MALDI mass spectrometry  

SciTech Connect (OSTI)

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS) has become a valuable tool for analyzing microorganisms. The speed with which data can be obtained from MALDI-MS makes this a potentially important tool for biological health hazard monitoring and forensic applications. The excitement in the mass spectrometry community in this potential field of application is evident by the expanding list of research laboratories pursuing development of MALDI-MS for bacterial identification. Numerous research groups have demonstrated the ability to obtain unique MALDI-MS spectra from intact bacterial cells and bacterial cell extracts. The ability to differentiate strains of the same species has been investigated. Reproducibility of MALDI-MS spectra from bacterial species under carefully controlled experimental conditions has also been demonstrated. Wang et al. have reported on interlaboratory reproducibility of the MALDI-MS analysis of several bacterial species. However, there are still issues that need to be addressed, including the careful control of experimental parameters for reproducible spectra and selection of optimal experimental parameters such as solvent and matrix.

KL Wahl; KH Jarman; NB Valentine; MT Kingsley; CE Petersen; ST Cebula; AJ Saenz

2000-03-21T23:59:59.000Z

72

Laser ablation electrospray ionization (LAESI) for atmospheric pressure, In vivo, and imaging mass spectrometry  

DOE Patents [OSTI]

The field of the invention is atmospheric pressure mass spectrometry (MS), and more specifically a process and apparatus which combine infrared laser ablation (LA) with electrospray ionization (ESI).

Vertes, Akos (Reston, VA); Nemes, Peter (Silver Spring, MD)

2011-11-29T23:59:59.000Z

73

Laser ablation electrospray ionization (LAESI) for atmospheric pressure, in vivo, and imaging mass spectrometry  

DOE Patents [OSTI]

The field of the invention is atmospheric pressure mass spectrometry (MS), and more specifically a process and apparatus which combine infrared laser ablation with electrospray ionization (ESI).

Vertes, Akos; Nemes, Peter

2014-08-19T23:59:59.000Z

74

Laser ablation electrospray ionization (LAESI) for atmospheric pressure, in vivo, and imaging mass spectrometry  

DOE Patents [OSTI]

The field of the invention is atmospheric pressure mass spectrometry (MS), and more specifically a process and apparatus which combine infrared laser ablation with electrospray ionization (ESI).

Vertes, Akos; Nemes, Peter

2013-07-16T23:59:59.000Z

75

Three-dimensional molecular imaging by infrared laser ablation electrospray ionization mass spectrometry  

DOE Patents [OSTI]

The field of the invention is atmospheric pressure mass spectrometry (MS), and more specifically a process and apparatus which combine infrared laser ablation with electrospray ionization (ESI).

Vertes, Akos; Nemes, Peter

2013-07-16T23:59:59.000Z

76

Three-dimensional molecular imaging by infrared laser ablation electrospray ionization mass spectrometry  

DOE Patents [OSTI]

The field of the invention is atmospheric pressure mass spectrometry (MS), and more specifically a process and apparatus which combine infrared laser ablation with electrospray ionization (ESI).

Vertes, Akos; Nemes, Peter

2012-10-30T23:59:59.000Z

77

Accelerator Mass Spectrometry | U.S. DOE Office of Science (SC...  

Office of Science (SC) Website

Mass Spectrometry at ANL and ORNL Developed at: Argonne National Laboratory (ANL), Oak Ridge National Laboratory (ORNL) Developed in: Current Result of NP research: Basic NP...

78

Atmospheric-Pressure Helium Inductively Coupled Plasmas for Elemental Mass Spectrometry  

Science Journals Connector (OSTI)

Analytical and fundamental characteristics of helium inductively coupled plasma mass spectrometry (He ICPMS) were explored for atmospheric-pressure plasmas generated in a 13-mm He...

Zhang, Hao; Nam, Sang-Ho; Cai, Mingxiang; Montaser, Akbar

1996-01-01T23:59:59.000Z

79

Detection of methoxylated anions of fullerenes by electrospray ionization mass spectrometry  

SciTech Connect (OSTI)

Electrospray ionization mass spectrometry (ESI-MS) has been applied to the study of the reactions of fullerenes in solution. The C[sub 60][sup [minus

Wilson, S.R.; Wu, Y. (New York Univ., NY (United States))

1993-11-03T23:59:59.000Z

80

E-Print Network 3.0 - analytical mass spectrometry Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of cluster primary ion beams for applications in secondary ion mass spectrometry (SIMS), motivated... surface analysis, microscopy, ion solid interactions, biological and...

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

E-Print Network 3.0 - atomic mass spectrometry Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of cluster primary ion beams for applications in secondary ion mass spectrometry (SIMS), motivated... surface analysis, microscopy, ion solid interactions, biological and...

82

Correction of accurate mass measurement for target compound verification by quadrupole time-of-flight mass spectrometry  

Science Journals Connector (OSTI)

The aim of this work is to evaluate quadrupole/time-of-flight (QTOF) mass spectrometry for simultaneous measurement of accurate mass and quantification of a target by using a stable isotopically labeled intern...

Harald C. Köfeler…

2005-03-01T23:59:59.000Z

83

Ion Mobility SpectrometryMass Spectrometry Performance Using Electrodynamic Ion Funnels and Elevated Drift Gas Pressures  

SciTech Connect (OSTI)

The ability of ion mobility spectrometry coupled with mass spectrometry (IMS-MS) to characterize biological mixtures has been illustrated over the past eight years. However, the challenges posed by the extreme complexity of many biological samples have demonstrated the need for higher resolution IMS-MS measurements. We have developed a higher resolution ESI-IMS-TOF MS by utilizing high pressure electrodynamic ion funnels at both ends of the IMS drift cell and operating the drift cell at an elevated pressure compared to a previous design. The ESI-IMS-TOF MS instrument consists of an ESI source, an hourglass ion funnel used for ion accumulation/injection into an 88 cm drift cell followed by a 10 cm ion funnel and a commercial orthogonal time-of-flight mass spectrometer providing high mass measurement accuracy. It was found that the rear (exit) ion funnel could be effectively operated as an extension of the drift cell when the DC fields were matched, allowing the instrument to have an effective drift region of 98 cm. Two differentially pumped quadrupole regions were used to couple the IMS and TOF MS to focus and minimize the ion transient time between the stages. The resolution of the instrument was evaluated at pressures ranging from 4 to12 Torr and ion mobility drift voltages of 16 V/cm (4 Torr) to 43 V/cm (12 Torr). An increase in resolution from 55 to 80 was observed from 4 to 12 Torr nitrogen drift gas with no loss in sensitivity. Given the increased usage of ion funnels prior to ion mobility separations, additional attention was directed towards the influence of drift gas on the observed ion populations trapped and transmitted using an electrodynamic ion funnel. The choice of drift gas was shown to influence the degree of ion heating and relative trapping efficiency within the ion funnel.

Baker, Erin Shammel; Clowers, Brian H.; Li, Fumin; Tang, Keqi; Tolmachev, Aleksey V.; Prior, David C.; Belov, Mikhail E.; Smith, Richard D.

2007-06-28T23:59:59.000Z

84

Dating Studies of Elephant Tusks Using Accelerator Mass Spectrometry  

SciTech Connect (OSTI)

A new method for determining the year of birth, the year of death, and hence, the age at death, of post-bomb and recently deceased elephants has been developed. The technique is based on Accelerator Mass Spectrometry radiocarbon analyses of small-sized samples extracted from along the length of a ge-line of an elephant tusk. The measured radiocarbon concentrations in the samples from a tusk can be compared to the {sup 14}C atmospheric bomb-pulse curve to derive the growth years of the initial and final samples from the tusk. Initial data from the application of this method to two tusks will be presented. Potentially, the method may play a significant role in wildlife management practices of African national parks. Additionally, the method may contribute to the underpinnings of efforts to define new international trade regulations, which could, in effect, decrease poaching and the killing of very young animals.

Sideras-Haddad, E; Brown, T A

2002-10-03T23:59:59.000Z

85

In situ secondary ion mass spectrometry analysis. 1992 Summary report  

SciTech Connect (OSTI)

The direct detection of tributyl phosphate (TBP) on rocks using molecular beam surface analysis [MBSA or in situ secondary ion mass spectrometry (SIMS)] is demonstrated. Quantities as low as 250 ng were detected on basalt and sandstone with little or no sample preparation. Detection of TBP on soil has proven to be more problematic and requires further study. Ethylenediaminetetraacetic acid (EDTA) is more difficult to detect because it is very reactive with surfaces of interest. Nevertheless, it is possible to detect EDTA if the acidity of the surface is controlled. The detection of EDTA-metal complexes is currently an open question, but evidence is presented for the detection of ions arising from a EDTA-lead complex. Carboxylic acids (i.e., citric, ascorbic, malic, succinic, malonic, and oxalic) give characteristic SIM spectra, but their detection on sample surfaces awaits evaluation.

Groenewold, G.S.; Applehans, A.D.; Ingram, J.C.; Delmore, J.E.; Dahl, D.A.

1993-01-01T23:59:59.000Z

86

Toward laser ablation Accelerator Mass Spectrometry of actinides  

SciTech Connect (OSTI)

A project to measure neutron capture cross sections of a number of actinides in a reactor environment by Accelerator Mass Spectrometry (AMS) at the ATLAS facility of Argonne National Laboratory is underway. This project will require the precise and accurate measurement of produced actinide isotopes in many (>30) samples irradiated in the Advanced Test Reactor at Idaho National Laboratory with neutron fluxes having different energy distributions. The AMS technique at ATLAS is based on production of highlycharged positive ions in an electron cyclotron resonance (ECR) ion source followed by acceleration in the ATLAS linac and mass-to-charge (m/q) measurement at the focus of the Fragment Mass Analyzer. Laser ablation was selected as the method of feeding the actinide material into the ion source because we expect it will have higher efficiency and lower chamber contamination than either the oven or sputtering techniques, because of a much narrower angular distribution of emitted material. In addition, a new multi-sample holder/changer to allow quick change between samples and a computer-controlled routine allowing fast tuning of the accelerator for different beams, are being developed. An initial test run studying backgrounds, detector response, and accelerator scaling repeatability was conducted in December 2010. The project design, schedule, and results of the initial test run to study backgrounds are discussed.

R. C. Pardo; F. G. Kondev; S. Kondrashev; C. Nair; T. Palchan; R. Scott; D. Seweryniak; R. Vondrasek; M. Paul; P. Collon; C. Deibel; M. Salvatores; G. Palmiotti; J. Berg; J. Fonnesbeck; G. Imel

2013-01-01T23:59:59.000Z

87

²?²Cf-plasma desorption mass spectrometry of RNA nucleosides  

E-Print Network [OSTI]

~ CH5 + CH3 CH3 + CH4 ~ C2H5 + H2 Proton or hydride transfer reactions of these secondary ions with the sample molecule produce the major portion of the CI mass spectra. Because the molecular ions are formed by these chemical reactions... low, and co'1'lisional deactivation between sample fons and air molecules results in a loss of intensity and resolution for the sample ions detected. -7 The vacuum in the mass spectrometer is maintained in the 10 16 torr region by a Sargent...

Piper, Duane Gilbert

1976-01-01T23:59:59.000Z

88

Conformational Analysis of Disordered Proteins Using H/D Exchange Mass Spectrometry  

E-Print Network [OSTI]

Conformational Analysis of Disordered Proteins Using H/D Exchange Mass Spectrometry By Copyright 2013 Theodore Robert Keppel Submitted to the graduate degree program in Chemistry and the Graduate Faculty of the University of Kansas...: Conformational Analysis of Disordered Proteins Using H/D Exchange Mass Spectrometry ______________________________ Chairperson David Weis Date Approved: 02/01/2013 iii Abstract Intrinsically disordered proteins (IDPs...

Keppel, Theodore Robert

2013-05-31T23:59:59.000Z

89

NMIS With Gamma Spectrometry for Attributes of Pu and HEU, Explosives and Chemical Agents  

SciTech Connect (OSTI)

The concept for the system described herein is an active/passive Nuclear Materials Identification System{sup 2} (NMIS) that incorporates gamma ray spectrometry{sup 3}. This incorporation of gamma ray spectrometry would add existing capability into this system. This Multiple Attribute System can determine a wide variety of attributes for Pu and highly enriched uranium (HEU) of which a selected subset could be chosen. This system can be built using commercial off the shelf (COTS) components. NMIS systems are at All-Russian Scientific Research Institute of Experimental Physics (VNIIEF) and Russian Federal Nuclear Center Institute of Technical Physics, (VNIITF) and measurements with Pu have been performed at VNIIEF and analyzed successfully for mass and thickness of Pu. NMIS systems are being used successfully for HEU at the Y-12 National Security Complex. The use of active gamma ray spectrometry for high explosive HE and chemical agent detection is a well known activation analysis technique, and it is incorporated here. This report describes the system, explains the attribute determination methods for fissile materials, discusses technical issues to be resolved, discusses additional development needs, presents a schedule for building from COTS components, and assembly with existing components, and discusses implementation issues such as lack of need for facility modification and low radiation exposure.

Mihalczo, J. T.; Mattingly, J. K.; Mullens, J. A.; Neal, J. S.

2002-05-10T23:59:59.000Z

90

Mass determination of megadalton-DNA Electrospray Ions usingCharge Detection Mass Spectrometry  

SciTech Connect (OSTI)

Charge detection mass spectrometry (CD-MS) has been used to determine the mass of double-stranded, circular DNA and single-stranded, circular DNA in the range of 2500 to 8000 base pairs (1.5-5.0 MDa). Simultaneous measurement of the charge and velocity of an electrostatically accelerated ion allows a mass determination of the ion, with instrument calibration determined independently of samples. Positive ion mass spectra of electrosprayed commercial DNA samples supplied in tris(hydroxymethyl)ethylenediamine tetraacetic acid buffer, diluted in 50 vol. percent acetonitrile, were obtained without cleanup of the sample. ACD mass spectrum constructed from 3000 ion measurements takes 10 min to acquire and yields the DNA molecular mass directly (mass resolution = 6). The data collected represent progress toward a more automatable alternative to sizing of DNA by gel electrophoresis. In addition to the mass spectra, CD-MS generates charge versus mass plots, which provide another means to investigate the creation and fate of large electrospray ions.

Schultz, Jocelyn C.; Hack, Christopher; Benner, Henry W.

1997-10-01T23:59:59.000Z

91

Time-of-Flight Secondary Ion Mass Spectrometry Based Molecular Histology of Human Spinal Cord Tissue and Motor Neurons  

Science Journals Connector (OSTI)

Secondary ion mass spectrometry is a powerful method for imaging biological samples with high spatial resolution. Whole section time-of-flight-secondary ion mass spectrometry (TOF-SIMS) scans and multivariate data analysis have been performed on the human ...

Jörg Hanrieder; Per Malmberg; Olle R. Lindberg; John S. Fletcher; Andrew G. Ewing

2013-08-15T23:59:59.000Z

92

Accelerator mass spectrometry in biomedical dosimetry: relationship between low-level exposure and covalent binding of heterocyclic amine carcinogens to DNA.  

Science Journals Connector (OSTI)

...Division, tCenter for Accelerator Mass Spectrometry, and Nuclear Chemistry Division...1990) ABSTRACT Accelerator mass spectrometry...Abbreviations: AMS, accelerator mass spectrometry...mixture was dried under vacuum in silica tubes and...

K W Turteltaub; J S Felton; B L Gledhill; J S Vogel; J R Southon; M W Caffee; R C Finkel; D E Nelson; I D Proctor; J C Davis

1990-01-01T23:59:59.000Z

93

Accelerator Mass Spectrometry | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Accelerator Mass Spectrometry at ANL Accelerator Mass Spectrometry at ANL and ORNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Accelerator Mass Spectrometry at ANL and ORNL Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Accelerator Mass Spectrometry at ANL and ORNL Developed at: Argonne National Laboratory (ANL), Oak Ridge National Laboratory (ORNL)

94

Detecting and Removing Data Artifacts in Hadamard Transform Ion Mobility-Mass Spectrometry Measurements  

Science Journals Connector (OSTI)

Applying Hadamard transform multiplexing to ion mobility separations (IMS) can significantly improve the signal-to-noise ratio and throughput for IMS coupled mass spectrometry (MS) measurements by increasing t...

Spencer A. Prost; Kevin L. Crowell…

2014-12-01T23:59:59.000Z

95

Colocalization of the Ganglioside GM1 and Cholesterol Detected by Secondary Ion Mass Spectrometry  

E-Print Network [OSTI]

here the use of secondary ion mass spectrometry (SIMS) to image the cholesterol-dependent cohesive of molecule specific images using a NanoSIMS. Simultaneous detection of six different ion species in SIMS

Boxer, Steven G.

96

Laser Ablation Inductively Coupled Plasma Mass Spectrometry Measurement of Isotope Ratios in Depleted Uranium Contaminated Soils  

Science Journals Connector (OSTI)

Laser ablation of pressed soil pellets was examined as a means of direct sample introduction to enable inductively coupled plasma mass spectrometry (ICP-MS) screening of soils for...

Seltzer, Michael D

2003-01-01T23:59:59.000Z

97

Measurements of Volatile Organic Compounds Using Proton Transfer Reaction - Mass Spectrometry during the MILAGRO 2006 Campaign  

E-Print Network [OSTI]

Volatile organic compounds (VOCs) were measured by proton transfer reaction – mass spectrometry (PTR-MS) on a rooftop in the urban mixed residential and industrial area North Northeast of downtown Mexico City as part of ...

Fortner, E. C.

98

Rapid determination of 5-hydroxymethylfurfural by DART ionization with time-of-flight mass spectrometry  

Science Journals Connector (OSTI)

DART (direct analysis in real time), a novel technique with wide potential for rapid screening analysis, coupled with high-resolution time-of-flight mass spectrometry (TOF-MS) has been used for quantitative analy...

Aleš Rajchl; Ladislava Drgová; Adéla Grégrová…

2013-05-01T23:59:59.000Z

99

Determination of trace impurities in zircaloy-2 and tellurium by spark source mass spectrometry  

Science Journals Connector (OSTI)

Determination of trace impurities in zircaloy-2 and tellurium by Spark Source Mass Spectrometry (SSMS) is reported. The advantage of SSMS lies in the fact that along with metallic trace constituents even the n...

K. L. Ramakumar; V. A. Raman; V. L. Sant…

1988-12-01T23:59:59.000Z

100

Systematic Optimization of Long Gradient Chromatography Mass Spectrometry for Deep Analysis of Brain Proteome  

Science Journals Connector (OSTI)

The development of high-resolution liquid chromatography (LC) is essential for improving the sensitivity and throughput of mass spectrometry (MS)-based proteomics. Here we present systematic optimization of a long gradient LC–MS/MS platform to enhance ...

Hong Wang; Yanling Yang; Yuxin Li; Bing Bai; Xusheng Wang; Haiyan Tan; Tao Liu; Thomas G. Beach; Junmin Peng; Zhiping Wu

2014-12-02T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

RAPID DETERMINATION OF 237 NP AND PU ISOTOPES IN WATER BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY  

SciTech Connect (OSTI)

A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of {sup 237}Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry; a hybrid approach. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4 to 6 hours, and can also be used for emergency response. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu, {sup 238}Pu, and {sup 239}Pu were measured by alpha spectrometry.

Maxwell, S.; Jones, V.; Culligan, B.; Nichols, S.; Noyes, G.

2010-06-23T23:59:59.000Z

102

Novel mass spectrometry mutation screening for contaminant impact analysis. 1998 annual progress report  

SciTech Connect (OSTI)

'The objective is to develop innovative mass spectrometry technology to achieve fast mutation screening from contaminated area and to reveal the linkage between gene mutation and contaminants. In this program, the author will try innovative approaches to improve mass resolution and detection efficiency for large DNA ions. Allel specific polymerase chain reaction will be coupled with mass spectrometry for rapid DNA mutation detection. The ultimate goal is to lead to the risk analysis of hazardous wastes to be routinely assessed at DNA level at an affordable cost. This report is for the work after 7 months of a 3-year project.'

Chen, C.H.

1998-06-01T23:59:59.000Z

103

Spatial Querying of Imaging Mass Spectrometry Data for the Biochemical Characterization of Anatomical Regions in Tissue  

E-Print Network [OSTI]

Spatial Querying of Imaging Mass Spectrometry Data for the Biochemical Characterization tissue section. In this paper we develop methods that enable spatial querying of MSI data. The objective that adds spatial information to mass spectral biochemical analysis. It delivers insight into the spatial

104

Automation of Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry Extraction of Eucalyptus Volatiles  

Science Journals Connector (OSTI)

......Eucalyptus metabolism Gas Chromatography-Mass...SPME) coupled with gas chromatography (GC...processes involved in the production, emission, and effects...Solid-Phase Microextraction Gas ChromatographyMass Spectrometry...significant savings in time and cost could be realized. In......

Cláudia A. Zini; III; Heather Lord; Eva Christensen; Teotônio F. de Assis; Elina B. Caramão; Janusz Pawliszyn

2002-03-01T23:59:59.000Z

105

On-line electrochemistry/electrospray mass spectrometry: Studies of oxidation of polycyclic aromatic hydrocarbons (PAHs)  

SciTech Connect (OSTI)

Studies of on-line coupling of electrochemistry with mass spectrometry, i.e., {open_quotes}electrochemical mass spectrometry{close_quotes} (EC/MS) date back to work by Bruckenstein et al. in the 1970`s. In these and other early experiments, porous working electrodes or permeable membranes were usually used as the interface between the cell and the MS ionization source which exclusively employed electron ionization (EI). As a result, only volatile products of electrochemical reactions could be detected by the mass line electrochemistry/mass spectroscopy was the coupling of an mass spectrometer (EC/TS/MS) reported by Hambitzer and g an aqueous ammonium acetate thermospray buffer solution, all detected or ammoniated species in the positive ion mode or as deprotonated or acetate adduct species in the negative ion mode. Radical cations or anions were not detected. Although {open_quotes}electrochemically assisted electrospray mass spectrometry{close_quotes} has been progressing for a few years, chiefly due to the pioneering efforts of Van Berkel and coworkers, on-line coupling electrochemistry with electrospray mass spectrometry (EC/ESMS) is still a developing area because of the experimental difficulties involved, such as high voltage hazard to the electrochemistry hardware (e.g. potentiostat), and MS signal suppression caused by the presence of high concentrations of supporting electrolytes. We report the coupling of an electrochemical device on-line with electrospray mass spectrometry (EC/ESMS) to extend the potential of ESMS to detect non-polar neutral compounds, and to monitor and identify intermediates and products generated by electrochemical reactions.

Xu, Xiaoming; Lu, Wenzhe; Cole, R.B. [Univ. of New Orleans, LA (United States)] [and others

1995-12-31T23:59:59.000Z

106

Apparatus and methods for continuous beam fourier transform mass spectrometry  

DOE Patents [OSTI]

A continuous beam Fourier transform mass spectrometer in which a sample of ions to be analyzed is trapped in a trapping field, and the ions in the range of the mass-to-charge ratios to be analyzed are excited at their characteristic frequencies of motion by a continuous excitation signal. The excited ions in resonant motions generate real or image currents continuously which can be detected and processed to provide a mass spectrum.

McLuckey, Scott A. (Oak Ridge, TN); Goeringer, Douglas E. (Oak Ridge, TN)

2002-01-01T23:59:59.000Z

107

C3Bio.org - Tags: Mass Spectrometry Data  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Dave J Borton, Hilkka Inkeri Kenttamaa Developments in atmospheric pressure ionization (API) techniques have revolutionized the mass spectrometric analysis of large and...

108

Review of Mass Spectrometry–Based Metabolomics in Cancer Research  

Science Journals Connector (OSTI)

...155-71. 2. Oliver SG , Winson MK, Kell DB, Baganz F.Systematic...hepatocellular carcinoma patients by ultra performance liquid chromatography-mass...hydroxylated, polyunsaturated ultra long-chain fatty acids in...performance liquid chromatography and ultra performance liquid chromatography-mass...

David B. Liesenfeld; Nina Habermann; Robert W. Owen; Augustin Scalbert; and Cornelia M. Ulrich

2013-12-01T23:59:59.000Z

109

Noise reduction in negative-ion quadrupole mass spectrometry  

DOE Patents [OSTI]

A quadrupole mass spectrometer (QMS) system having an ion source, quadrupole mass filter, and ion collector/recorder system. A weak, transverse magnetic field and an electron collector are disposed between the quadrupole and ion collector. When operated in negative ion mode, the ion source produces a beam of primarily negatively-charged particles from a sample, including electrons as well as ions. The beam passes through the quadrupole and enters the magnetic field, where the electrons are deflected away from the beam path to the electron collector. The negative ions pass undeflected to the ion collector where they are detected and recorded as a mass spectrum.

Chastagner, Philippe (3134 Natalie Cir., Augusta, GA 30909-2748)

1993-01-01T23:59:59.000Z

110

Department of Chemistry Mass Spectrometry Sample Submission Form  

E-Print Network [OSTI]

's ID. · You are responsible to pick up your samples within 7 days after the analysis. · Please call 801: [ ] Standard (LRMS) [ ] Exact Mass (HRMS) Ionization type: [ ] ESI [ ] MALDI [ ] EI (GC/MS only) Scans required

Simons, Jack

111

Secondary Ion Mass Spectrometry Imaging of Dictyostelium discoideum...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to enable this. In this report, we employed Bi3 bombardment time-of-flight (Bi3 ToF-SIMS) and C60 bombardment Fourier transform ion cyclotron resonance secondary ion mass...

112

Single cancer cell imaging and cell extract analysis using time-of-flight secondary ion mass spectrometry (TOF-SIMS)  

Science Journals Connector (OSTI)

...secondary ion mass spectrometry (TOF-SIMS) Kristen S. Kulp Kuang J. Wu David L...Secondary Ion Mass Spectrometry (TOF-SIMS) to image and identify individual cells...A surface scanning procedure, TOF-SIMS is uniquely suited to the sensitive detection...

Kristen S. Kulp; Kuang J. Wu; David L. Shattuck; Ligang Wu; Erik J. Nelson; Jennifer L. Montgomery; James S. Felton; Mark G. Knize

2005-05-01T23:59:59.000Z

113

Composition of nanoparticles in optical fibers by Secondary Ion Mass Spectrometry  

E-Print Network [OSTI]

encapsulate LI to produce « engineered » spectroscopic properties. To determine the composition of DNP-SIMS investigation of boron distribution in steels," Surf. Interface Anal. 43, 573-575 (2011). 12. C. Lechene, F imaging of mammalian and bacterial cells using stable isotope mass spectrometry," Journal of Biology 5, 20

Boyer, Edmond

114

Tandem Mass Spectrometry for the Direct Assay of Lysosomal Enzymes in  

E-Print Network [OSTI]

. Mucopolysaccharidosis type I (MPS-I)4 is a lysosomal storage disorder caused by the deficiency of -L- iduronidase (Id-Scheie syndromes. IdA is essential for the degradation within lysosomes of the glycosamino- glycans dermatan recognition of MPS-I. Flu- orometric, radiometric, and electrospray ionization­ tandem mass spectrometry (ESI

Gelb, Michael

115

FOCUS: HARSH ENVIRONMENT MASS SPECTROMETRY Field Testing of Lake Water Chemistry with a  

E-Print Network [OSTI]

FOCUS: HARSH ENVIRONMENT MASS SPECTROMETRY Field Testing of Lake Water Chemistry with a Portable waters. KOALA is a backpackable MS operated from above the water surface, in which samples are pumped for temperature control of a membrane inlet when steep thermal gradients are present in a water body, as well

Entekhabi, Dara

116

Visual Steering and Verification of Mass Spectrometry Data Factorization in Air Quality Research  

E-Print Network [OSTI]

quality research involves the analysis of high-dimensional single particle mass spectrometry data. We data at significantly increased speed and a higher degree of ease. Index Terms--Dimension reduction of numerical error metrics, multi-dimensional data visualization. 1 INTRODUCTION Atmospheric particles increase

Hamann, Bernd

117

Desorption Electrospray Ionization Mass Spectrometry for Trace Analysis of Agrochemicals in Food  

Science Journals Connector (OSTI)

Desorption Electrospray Ionization Mass Spectrometry for Trace Analysis of Agrochemicals in Food ... Desorption electrospray ionization (DESI) is applied to the rapid, in situ, direct qualitative and quantitative (ultra)trace analysis of agrochemicals in foodstuffs. ... The results proved that DESI allows the detection and confirmation of traces of agrochemicals in actual market-purchased samples. ...

Juan F. García-Reyes; Ayanna U. Jackson; Antonio Molina-Díaz; R. Graham Cooks

2008-12-17T23:59:59.000Z

118

Apparatus and method for hydrogen and oxygen mass spectrometry of the terrestrial magnetosphere  

DOE Patents [OSTI]

A detector element for mass spectrometry of a flux of heavy and light ions, that includes: a first detector to detect light ions that transit through a foil operatively placed in front of the first detector, and a second detector that detects the flux of heavy and light ions.

Funsten, Herbert O. (Los Alamos, NM); Dors, Eric E. (Los Alamos, NM); Harper, Ronnie W. (Los Alamos, NM); Reisenfeld, Daniel B. (Stevensville, MT)

2007-05-15T23:59:59.000Z

119

Apparatus for preparing a sample for mass spectrometry  

DOE Patents [OSTI]

An apparatus is described for preparing a sample for analysis by a mass spectrometer system. The apparatus has an entry chamber and an ionization chamber separated by a skimmer. A capacitor having two space-apart electrodes followed by one or more ion-imaging lenses is disposed in the ionization chamber. The chamber is evacuated and the capacitor is charged. A valve injects a sample gas in the form of sample pulses into the entry chamber. The pulse is collimated by the skimmer and enters the ionization chamber. When the sample pulse passes through the gap between the electrodes, it discharges the capacitor and is thereby ionized. The ions are focused by the imaging lenses and enter the mass analyzer, where their mass and charge are analyzed. 1 figures.

Villa-Aleman, E.

1994-05-10T23:59:59.000Z

120

High explosives vapor detection by atmospheric sampling glow discharge ionization/tandem mass spectrometry  

SciTech Connect (OSTI)

The combination of atmospheric sampling glow discharge ionization with tandem mass spectrometry for the detection of traces of high explosives is described. Particular emphasis is placed on use of the quadrupole ion trap as the type of tandem mass spectrometer. Atmospheric sampling glow discharge provides a simple, rugged, and efficient means for anion formation while the quadrupole ion trap provides for efficient tandem mass spectrometry. Mass selective ion accumulation and non-specific ion activation methods can be used to overcome deleterious effects arising from ion/ion interactions. Such interactions constitute the major potential technical barrier to the use of the ion trap for real-time monitoring of targeted compounds in uncontrolled and highly variable matrices. Tailored waveforms can be used to effect both mass selective ion accumulation and ion activation. Concatenated tailored waveforms allow for both functions in a single experiment thereby providing the capability for monitoring several targeted species simultaneously. The combination of atmospheric sampling glow discharge ionization with a state-of-the-art analytical quadrupole ion trap is a highly sensitive and specific detector for traces of high explosives. The combination is also small and inexpensive relative to virtually any other form of tandem mass spectrometry. The science and technology underlying the glow discharge/ion trap combination is sufficiently mature to form the basis for an engineering effort to make the detector portable. 85 refs.

McLuckey, S.A.; Goeringer, D.E.; Asano, K.G. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.

1996-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Evaluation of Hypervelocity Gold Nanoparticles for Nanovolume Surface Mass Spectrometry  

E-Print Network [OSTI]

in Figure VI-1 ................................................................................................ 166 VI-3 SI yields for samples containing various amounts of silver and gold on top of a PMMA film analyzed by massive gold clusters... and Bi+ ........ 169 VI-4 Negative mode mass spectrum from atomic-SIMS analysis of a PMMA surface ........................................................................................... 170 VI-5 Proposed structures for fragment ions...

DeBord, John 1986-

2012-08-16T23:59:59.000Z

122

National Centre for Biological Sciences Mass Spectrometry Facility  

E-Print Network [OSTI]

: Sample Information Number of samples: Sample ID: Concentration: Solubility: Expected mass (Da): Molecular: Protein Peptide Lipid Nucleic acid Others (specify) Analysis Requirement ESI MS, low resolution ESI MS, high resolution LC-ESI MS LC-ESI MS/MS Others (specify) Signature of research supervisor: Signature

Bhalla, Upinder S.

123

Explanatory Optimization of Protein Mass Spectrometry via Genetic Search  

E-Print Network [OSTI]

of the mass spectrometer settings that accounts for much of this success. Specifically, the conditions of Wales, Aberystwyth, Ceredigion SY23 3DD, U.K. Optimizing experimental conditions for the effective analy that little or no a priori knowledge of the optimal conditions is available. There is much current interest

Fernandez, Thomas

124

Coulomb crystal mass spectrometry in a digital ion trap  

E-Print Network [OSTI]

We present a mass spectrometric technique for identifying the masses and relative abundances of Coulomb-crystallized ions held in a linear Paul trap. A digital radiofrequency waveform is employed to generate the trapping potential, as this can be cleanly switched off, and static dipolar fields subsequently applied to the trap electrodes for ion ejection. Excellent detection efficiency is demonstrated for Ca+ and CaF+ ions from bi-component Ca+/CaF+ Coulomb crystals prepared by reaction of Ca+ with CH3F. A quantitative linear relationship is observed between ion number and the corresponding integrated TOF peak, independent of the ionic species. The technique is applicable to a diverse range of multi-component Coulomb crystals - demonstrated here for Ca+/NH3+/NH4+ and Ca+/CaOH+/CaOD+ crystals - and will facilitate the measurement of ion-molecule reaction rates and branching ratios in complicated reaction systems.

Deb, Nabanita; Smith, Alexander D; Keller, Matthias; Rennick, Christopher J; Heazlewood, Brianna R; Softley, Timothy P

2015-01-01T23:59:59.000Z

125

Plume collimation for laser ablation electrospray ionization mass spectrometry  

DOE Patents [OSTI]

In various embodiments, a device may generally comprise a capillary having a first end and a second end; a laser to emit energy at a sample in the capillary to ablate the sample and generate an ablation plume in the capillary; an electrospray apparatus to generate an electrospray plume to intercept the ablation plume to produce ions; and a mass spectrometer having an ion transfer inlet to capture the ions. The ablation plume may comprise a collimated ablation plume. The device may comprise a flow cytometer. Methods of making and using the same are also described.

Vertes, Akos; Stolee, Jessica A.

2014-09-09T23:59:59.000Z

126

A simple algorithm improves mass accuracy to 50-100 ppm for delayed extraction linear MALDI-TOF mass spectrometry  

SciTech Connect (OSTI)

A simple mathematical technique for improving mass calibration accuracy of linear delayed extraction matrix assisted laser desorption ionization time-of-flight mass spectrometry (DE MALDI-TOF MS) spectra is presented. The method involves fitting a parabola to a plot of Dm vs. mass data where Dm is the difference between the theoretical mass of calibrants and the mass obtained from a linear relationship between the square root of m/z and ion time of flight. The quadratic equation that describes the parabola is then used to correct the mass of unknowns by subtracting the deviation predicted by the quadratic equation from measured data. By subtracting the value of the parabola at each mass from the calibrated data, the accuracy of mass data points can be improved by factors of 10 or more. This method produces highly similar results whether or not initial ion velocity is accounted for in the calibration equation; consequently, there is no need to depend on that uncertain parameter when using the quadratic correction. This method can be used to correct the internally calibrated masses of protein digest peaks. The effect of nitrocellulose as a matrix additive is also briefly discussed, and it is shown that using nitrocellulose as an additive to a CHCA matrix does not significantly change initial ion velocity but does change the average position of ions relative to the sample electrode at the instant the extraction voltage is applied.

Hack, Christopher A.; Benner, W. Henry

2001-10-31T23:59:59.000Z

127

Direct analysis of cellulose in poplar stem by matrixassisted laser desorption/ionization imaging mass spectrometry  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

analysis analysis of cellulose in poplar stem by matrix- assisted laser desorption/ionization imaging mass spectrometry Seokwon Jung 1,3 , Yanfeng Chen 3 , M. Cameron Sullards 1,3 and Arthur J. Ragauskas 1,2,3 * 1 BioEnergy Science Center, Georgia Institute of Technology, 500 10 th St., Atlanta, GA 30332, USA 2 Institute of Paper Science and Technology, Georgia Institute of Technology, 500 10 th St., Atlanta, GA 30332, USA 3 School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, GA 30332, USA Received 10 July 2010; Revised 9 August 2010; Accepted 23 August 2010 Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) was applied to the analysis of the spatial distribution of cellulose on a cross-section of juvenile poplar (Populus deltoids) stems. Microcrystalline cellulose (MCC) was used to optimize matrix (2,5-dihydroxybenzoic

128

Fundamentals and Applications of Electrospray Ionization Mass Spectrometry for Petroleum Characterization  

Science Journals Connector (OSTI)

Fundamentals and Applications of Electrospray Ionization Mass Spectrometry for Petroleum Characterization ... We are reporting a study of the fundamental and application aspects of positive-ion electrospray ionization (ESI+) for petroleum characterization. ... The gas-phase basicities (GBs) were experimental data from the NIST Chemistry WebBook,33 whereas the aqueous basicities (pKb) were derived from Lange's Handbook of Chemistry, 14th Edition. ...

Kuangnan Qian; Kathleen E. Edwards; John H. Diehl; Larry A. Green

2004-09-10T23:59:59.000Z

129

Final LDRD report : development of sample preparation methods for ChIPMA-based imaging mass spectrometry of tissue samples.  

SciTech Connect (OSTI)

The objective of this short-term LDRD project was to acquire the tools needed to use our chemical imaging precision mass analyzer (ChIPMA) instrument to analyze tissue samples. This effort was an outgrowth of discussions with oncologists on the need to find the cellular origin of signals in mass spectra of serum samples, which provide biomarkers for ovarian cancer. The ultimate goal would be to collect chemical images of biopsy samples allowing the chemical images of diseased and nondiseased sections of a sample to be compared. The equipment needed to prepare tissue samples have been acquired and built. This equipment includes an cyro-ultramicrotome for preparing thin sections of samples and a coating unit. The coating unit uses an electrospray system to deposit small droplets of a UV-photo absorbing compound on the surface of the tissue samples. Both units are operational. The tissue sample must be coated with the organic compound to enable matrix assisted laser desorption/ionization (MALDI) and matrix enhanced secondary ion mass spectrometry (ME-SIMS) measurements with the ChIPMA instrument Initial plans to test the sample preparation using human tissue samples required development of administrative procedures beyond the scope of this LDRD. Hence, it was decided to make two types of measurements: (1) Testing the spatial resolution of ME-SIMS by preparing a substrate coated with a mixture of an organic matrix and a bio standard and etching a defined pattern in the coating using a liquid metal ion beam, and (2) preparing and imaging C. elegans worms. Difficulties arose in sectioning the C. elegans for analysis and funds and time to overcome these difficulties were not available in this project. The facilities are now available for preparing biological samples for analysis with the ChIPMA instrument. Some further investment of time and resources in sample preparation should make this a useful tool for chemical imaging applications.

Maharrey, Sean P.; Highley, Aaron M.; Behrens, Richard, Jr.; Wiese-Smith, Deneille

2007-12-01T23:59:59.000Z

130

2?52Cf plasma desorption mass spectrometry of metal clusters  

E-Print Network [OSTI]

August 1991 Major Subject: Chemistry s Cf PLASMA DESORPTION MASS SPECTROMETRY OF METAL CLUSTERS A Thesis by JANITA MURIEL HUGHES Approved as to style and content by: R. D. ac ane (Chair of Co 'uee) J. P. Fac er (Member) A. . aray (Member) M... and negative ion spectra. However, close-packed complexes like [Pt (CO), g" form cluster cor- responding to the oligomeric species, [(Pt ), (CO)?], from n=2 to n=20. The latter structure contains 520 platinum atoms with an observed mass in excess of m/z 100...

Hughes, Janita Muriel

1991-01-01T23:59:59.000Z

131

Gas chromatography–mass spectrometry analysis of fatty acid profiles of Antarctic and non-Antarctic yeasts  

Science Journals Connector (OSTI)

The fatty acid profiles of Antarctic (n = 7) and non-Antarctic yeasts (n = 7) grown at different temperatures were analysed by gas chromatography–mass spectrometry. The Antarctic yeasts were enriched in oleic 18:...

Mohammad Bhuiyan; David Tucker; Kenneth Watson

2014-08-01T23:59:59.000Z

132

A high selective and sensitive liquid chromatography–tandem mass spectrometry method for quantization of BPA urinary levels in children  

Science Journals Connector (OSTI)

A selective and highly sensitive liquid chromatography–tandem mass spectrometry method has been developed and validated for determination of Bisphenol A (BPA) in human urine using labeled d6-BPA as internal stand...

Carla Nicolucci; Sergio Rossi; Ciro Menale…

2013-11-01T23:59:59.000Z

133

Automatic Gain Control in Mass Spectrometry using a Jet Disrupter Electrode in an Electrodynamic Ion Funnel  

SciTech Connect (OSTI)

We report on the use of a jet disrupter electrode in an electrodynamic ion funnel as an electronic valve to regulate the intensity of the ion beam transmitted through the interface of a mass spectrometer in order to perform automatic gain control (AGC). The ion flux is determined by either directly detecting the ion current on the conductance limiting orifice of the ion funnel or using a short mass spectrometry acquisition. Based upon the ion flux intensity, the voltage of the jet disrupter is adjusted to alter the transmission efficiency of the ion funnel to provide a desired ion population to the mass analyzer. Ion beam regulation by an ion funnel is shown to provide an unbiased control to within a few percent of a targeted ion intensity or abundance. The utility of ion funnel AGC was evaluated using a protein tryptic digest analyzed with liquid chromatography Fourier transform ion cyclotron resonance (LC-FTICR) mass spectrometry. The ion population in the ICR cell was accurately controlled to a variety of different levels, which improved data quality and provided better mass measurement accuracy.

Page, Jason S.; Bogdanov, Bogdan; Vilkov, Andrey N.; Prior, David C.; Buschbach, Michael A.; Tang, Keqi; Smith, Richard D.

2005-02-01T23:59:59.000Z

134

Mass Transfer Constraints On The Chemical Evolution Of An Active  

Open Energy Info (EERE)

Mass Transfer Constraints On The Chemical Evolution Of An Active Mass Transfer Constraints On The Chemical Evolution Of An Active Hydrothermal System, Valles Caldera, New Mexico Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Mass Transfer Constraints On The Chemical Evolution Of An Active Hydrothermal System, Valles Caldera, New Mexico Details Activities (4) Areas (2) Regions (0) Abstract: Partial equilibrium conditions occur between fluids and secondary minerals in the Valles hydrothermal system, contained principally in the Tertiary rhyolitic Bandelier Tuff. The mass transfer processes are governed by reactive phase compositions, surface areas, water-rock ratios, reaction rates, and fluid residence times. Experimental dissolution of the vitric phase of the tuff was congruent with respect to Cl in the solid and

135

Improving the Sensitivity of Mass Spectrometry by Using a New Sheath Flow Electrospray Emitter Array at Subambient Pressures  

SciTech Connect (OSTI)

Arrays of chemically etched emitters with individualized sheath gas capillaries have been developed to enhance electrospray ionization (ESI) at subambient pressures. By including an emitter array in a subambient pressure ionization with nanoelectrospray (SPIN) source, ionization and transmission efficiency can be maximized allowing for increased sensitivity in mass spectrometric analyses. The SPIN source eliminates the major ion losses at conventional ESI-mass spectrometry (MS) interface by placing the emitter in the first vacuum region of the instrument. To facilitate stable electrospray currents in such conditions we have developed an improved emitter array with individualized sheath gas around each emitter. The utility of the new emitter arrays for generating stable multi-electrosprays at subambient pressures was probed by coupling the emitter array/SPIN source with a time of flight (TOF) mass spectrometer. The instrument sensitivity was compared between single emitter/SPIN-MS and multi-emitter/SPIN-MS configurations using an equimolar solution of 9 peptides. An increase in sensitivity correlative to the number of emitters in the array was observed.

Cox, Jonathan T.; Marginean, Ioan; Kelly, Ryan T.; Smith, Richard D.; Tang, Keqi

2014-12-01T23:59:59.000Z

136

Chemical oxidation of tryptic digests to improve sequence coverage in peptide mass fingerprint protein identification  

E-Print Network [OSTI]

Peptide mass fingerprinting (PMF) of protein digests is a widely-accepted method for protein identification in MS-based proteomic studies. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI) is the technique of choice in PMF...

Lucas, Jessica Elaine

2004-09-30T23:59:59.000Z

137

Nanoelectrospray ion generation for high-throughput mass spectrometry using a micromachined ultrasonic ejector array  

SciTech Connect (OSTI)

Ultrasonic electrospray ionization (ESI) for high-throughput mass spectrometry is demonstrated using a silicon micromachined microarray. The device uses a micromachined ultrasonic atomizer operating in the 900 kHz-2.5 MHz range for droplet generation and a metal electrode in the fluid cavity for ionization. Since the atomization and ionization processes are separated, the ultrasonic ESI source shows the potential for operation at low voltages with a wide range of solvents in contrast with conventional capillary ESI technology. This is demonstrated using the ultrasonic ESI microarray to obtain the mass spectrum of a 10 {mu}M reserpine sample on a time of flight mass spectrometer with 197:1 signal-to-noise ratio at an ionization potential of 200 V.

Aderogba, S.; Meacham, J.M.; Degertekin, F.L.; Fedorov, A.G.; Fernandez, F.M. [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2005-05-16T23:59:59.000Z

138

Elemental and isotopic analysis of inorganic salts by laser desorption ionization mass spectrometry  

SciTech Connect (OSTI)

Laser desorption ionization mass spectrometry is applied for the analysis of elements as well as their isotopic composition in different inorganic salts. At very low laser energies the inorganic ions are desorbed and ionized from the thin layer of the sample surface. The naturally occurring isotopes of alkali and silver ions are resolved using time of flight mass spectrometer. Further increase in laser energy shows the appearance of Al, Cr, and Fe ions in the mass spectra. This indicates the penetration laser beam beyond the sample surface leading to the ablation of sample target at higher energies. The simultaneous appearance of atomic ions from the sample target at relatively higher laser energies hampers the unambiguous identification of amino acid residues from the biomolecular ions in MALDI-MS.

Jayasekharan, T.; Sahoo, N. K. [Applied Spectroscopy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2013-02-05T23:59:59.000Z

139

Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade boron carbide  

E-Print Network [OSTI]

1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade boron carbide powder and pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Total Carbon by Combustion and Gravimetry 7-17 Total Boron by Titrimetry 18-28 Isotopic Composition by Mass Spectrometry 29-38 Chloride and Fluoride Separation by Pyrohydrolysis 39-45 Chloride by Constant-Current Coulometry 46-54 Fluoride by Ion-Selective Electrode 55-63 Water by Constant-Voltage Coulometry 64-72 Impurities by Spectrochemical Analysis 73-81 Soluble Boron by Titrimetry 82-95 Soluble Carbon by a Manometric Measurement 96-105 Metallic Impurities by a Direct Reader Spectrometric Method 106-114

American Society for Testing and Materials. Philadelphia

2004-01-01T23:59:59.000Z

140

Imaging with Mass Spectrometry: A SIMS and VUV-Photoionization Study of Ion-Sputtered Atoms and Clusters from GaAs and Au  

SciTech Connect (OSTI)

A new mass spectrometry surface imaging method is presented in which ion-sputtered neutrals are postionized by wavelength-tunable vacuum ultraviolet (VUV) light from a synchrotron source. Mass spectra and signal counts of the photoionized neutrals from GaAs (100) and Au are compared to those of the secondary ions. While clusters larger than dimers are more efficiently detected as secondary ions, certain species, such as As2, Au and Au2, are more efficiently detected through the neutral channel. Continuously tuning the photon wavelength allows photoionization efficiency (PIE) curves to be obtained for sputtered Asm (m=1,2) and Aun (n=1-4). From the observed ionization thresholds, sputtered neutral As and Au show no clear evidence of electronic excitation, while neutral clusters have photoionization onsets shifted to lower energies by ~;;0.3 eV. These shifts are attributed to unresolved vibrational and rotational excitations. High-spatial resolution chemical imaging with synchrotron VUV postionization is demonstrated at two different photon energies using a copper TEM grid embedded in indium. The resulting images are used to illustrate the use of tunable VUV light for verifying mass peak assignments by exploiting the unique wavelength-dependent PIE of each sputtered neutral species. This capability is valuable for identifying compounds when imaging chemically complex systems with mass spectrometry-based techniques.

Takahashi, Lynelle; Zhou, Jia; Wilson, Kevin R.; Leone, Stephen R.; Ahmed, Musahid

2008-12-05T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Monitoring Genetic and Metabolic Potential for In-Site Bioremediation: Mass Spectrometry  

SciTech Connect (OSTI)

A number of DOE sites are contaminated with mixtures of dense non-aqueous phase liquids (DNAPLs) such as carbon tetrachloride, chloroform, perchloroethylene, and trichloroethylene. At many of these sites, in situ microbial bioremediation is an attractive strategy for cleanup, since it has the potential to degrade DNAPLs in situ without the need for pump-and-treat or soil removal procedures, and without producing toxic byproducts. A rapid screening method to determine broad range metabolic and genetic potential for contaminant degradation would greatly reduce the cost and time involved in assessment for in situ bioremediation, as well as for monitoring ongoing bioremediation treatment. The objective of this project was the development of mass-spectrometry-based methods to screen for genetic potential for both assessment and monitoring of in situ bioremediation of DNAPLs. These methods were designed to provide more robust and routine methods for DNA-based characterization of the genetic potential of subsurface microbes for degrading pollutants. Specifically, we sought to (1) Develop gene probes that yield information equivalent to conventional probes, but in a smaller size that is more amenable to mass spectrometric detection, (2) Pursue improvements to matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) methodology in order to allow its more general application to gene probe detection, and (3) Increase the throughput of microbial characterization by integrating gene probe preparation, purification, and MALDI-MS analysis.

Buchanan, M.V.

2000-07-20T23:59:59.000Z

142

Using electrospray ionization FTICR mass spectrometry to study competitive binding of inhibitors to carbonic anhydrase  

SciTech Connect (OSTI)

We report a method based on mass spectrometry for the characterization of noncovalent complexes of proteins with mixtures of ligands; this method is relevant to the study of drug leads and may be useful in screening libraries for tight-binding compounds. This study describes the competitive binding of inhibitors derived from para-substituted benzenesulfonamides to bovine carbonic anhydrase II (BCAII, EC 4.2.1.1) using this technique. Relative binding constants and structural information for a mixture of inhibitors can be obtained in a single experiment using ESI-FTICR-MS. The work demonstrates that ESI-MS has significant potential for measuring relative binding affinities and characterizing the structures of ligands associated noncovalently to proteins. We have detected noncovalent complexes in the gas phase for ligands having values of K{sub b} as low as 1.7 x 10{sup 6} M{sup -1} in solution. The technique also allowed identification of tightbinding ligands from small libraries. The structures of inhibitors having similar masses can be identified by the high-resolution and multistep dissociation mass spectrometry of which FTICR is uniquely capable. This range of capabilities for ESI-FTICR-MS should be widely useful in medicinal chemistry. 22 refs., 2 figs.

Cheng, X.; Chen, R.; Bruce, J.E.; Schwartz, B.L.; Anderson, G.A.; Hofstadler, S.A.; Gale, D.C.; Smith, R.D. [Pacific Northwest Lab., Richland, WA (United States); Gao, J.; Sigal, G.B.; Mammen, M.; Whitesides, G.M. [Harvard Univ., Cambridge, MA (United States)

1995-08-30T23:59:59.000Z

143

VUV photoionization time-of-flight mass spectrometry of flash pyrolysis of silane and disilane  

Science Journals Connector (OSTI)

Flash pyrolysis of silane, SiH4, and disilane, Si2H6, diluted in He or Ar (1%), was carried out at temperatures ranging from ?700 to ?1500 K. After a short reaction time of ?20 ?s, the initial products were isolated in a supersonic molecular beam and detected by single vacuum ultra-violet (VUV) photon (?=118 or 121 nm) ionization time-of-flight mass spectrometry (TOFMS). Initial decomposition and reaction products, both free radical intermediates and stable species, were directly observed, which included SiH2 and Si2H4.

Steven D. Chambreau; Jingsong Zhang

2001-01-01T23:59:59.000Z

144

Toward Single-Cell Analysis by Plume Collimation in Laser Ablation Electrospray Ionization Mass Spectrometry  

Science Journals Connector (OSTI)

In the plume collimation experiments, laser radiation was delivered through a germanium oxide (GeO2) optical fiber (450 ?m core diameter, HP Fiber, Infrared Fiber Systems, Inc., Silver Spring, MD) with a tip etched in a 2% nitric acid solution as described earlier. ... Upon ablation in the capillary, a collimated plume emerges (shown in blue) and is ionized by an electrospray. ... Individual sea urchin eggs were selected by using the micromanipulator system and deposited into a capillary for LAESI mass spectrometry with plume collimation. ...

Jessica A. Stolee; Akos Vertes

2013-02-28T23:59:59.000Z

145

Standard test methods for chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide (Gd2O3) powder  

E-Print Network [OSTI]

1.1 These test methods cover procedures for the chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide powders to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Carbon by Direct CombustionThermal Conductivity C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Total Chlorine and Fluorine by Pyrohydrolysis Ion Selective Electrode C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Loss of Weight on Ignition 7-13 Sulfur by CombustionIodometric Titration Impurity Elements by a Spark-Source Mass Spectrographic C761 Test Methods for Chemical, Mass Spectrometric, Spectrochemical,Nuclear, and Radiochemical Analysis of Uranium Hexafluoride C1287 Test Method for Determination of Impurities In Uranium Dioxide By Inductively Coupled Plasma Mass Spectrometry Gadolinium Content in Gadolinium Oxid...

American Society for Testing and Materials. Philadelphia

2006-01-01T23:59:59.000Z

146

Ultra-high-mass mass spectrometry with charge discrimination using cryogenic detectors  

DOE Patents [OSTI]

An ultra-high-mass time-of-flight mass spectrometer using a cryogenic particle detector as an ion detector with charge discriminating capabilities. Cryogenic detectors have the potential for significantly improving the performance and sensitivity of time-of-flight mass spectrometers, and compared to ion multipliers they exhibit superior sensitivity for high-mass, slow-moving macromolecular ions and can be used as "stop" detectors in time-of-flight applications. In addition, their energy resolving capability can be used to measure the charge state of the ions. Charge discrimination is very valuable in all time-of-flight mass spectrometers. Using a cryogenically-cooled Nb-Al.sub.2 O.sub.3 -Nb superconductor-insulator-superconductor (SIS) tunnel junction (STJ) detector operating at 1.3 K as an ion detector in a time-of-flight mass spectrometer for large biomolecules it was found that the STJ detector has charge discrimination capabilities. Since the cryogenic STJ detector responds to ion energy and does not rely on secondary electron production, as in the conventionally used microchannel plate (MCP) detectors, the cryogenic detector therefore detects large molecular ions with a velocity-independent efficiency approaching 100%.

Frank, Matthias (Berkeley, CA); Mears, Carl A. (Oakland, CA); Labov, Simon E. (Berkeley, CA); Benner, W. Henry (Danville, CA)

1999-01-01T23:59:59.000Z

147

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network [OSTI]

1.4.2 Atomic Absorption5.3.2 Atomic Absorption Spectrometry . . . . . . . . . . .ablation and diode laser-atomic absorption spectrometry”,

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

148

Towards secondary ion mass spectrometry on the helium ion microscope: An experimental and simulation based feasibility study with He{sup +} and Ne{sup +} bombardment  

SciTech Connect (OSTI)

The combination of the high-brightness He{sup +}/Ne{sup +} atomic level ion source with secondary ion mass spectrometry detection capabilities opens up the prospect of obtaining chemical information with high lateral resolution and high sensitivity on the Zeiss ORION helium ion microscope. The analytical performance in terms of sputtering yield, useful yield, and detection limit is studied and subsequently optimized by oxygen and cesium flooding. Detection limits down to 10{sup -6} and 10{sup -5} can be obtained for silicon using Ne{sup +} and He{sup +}, respectively. A simulation based study reveals furthermore that a lateral resolution <10 nm can be obtained.

Wirtz, T.; Vanhove, N.; Pillatsch, L.; Dowsett, D. [Department of Science and Analysis of Materials (SAM), Centre de Recherche Public - Gabriel Lippmann, 41 rue du Brill, L-4422 Belvaux (Luxembourg); Sijbrandij, S.; Notte, J. [Carl Zeiss NTS LLC, One Corporation Way, Peabody, Massachusetts 01960 (United States)

2012-07-23T23:59:59.000Z

149

Analyzing Nuclear Fuel Cycles from Isotopic Ratios of Waste Products Applicable to Measurement by Accelerator Mass Spectrometry  

SciTech Connect (OSTI)

An extensive study was conducted to determine isotopic ratios of nuclides in spent fuel that may be utilized to reveal historical characteristics of a nuclear reactor cycle. This forensic information is important to determine the origin of unknown nuclear waste. The distribution of isotopes in waste products provides information about a nuclear fuel cycle, even when the isotopes of uranium and plutonium are removed through chemical processing. Several different reactor cycles of the PWR, BWR, CANDU, and LMFBR were simulated for this work with the ORIGEN-ARP and ORIGEN 2.2 codes. The spent fuel nuclide concentrations of these reactors were analyzed to find the most informative isotopic ratios indicative of irradiation cycle length and reactor design. Special focus was given to long-lived and stable fission products that would be present many years after their creation. For such nuclides, mass spectrometry analysis methods often have better detection limits than classic gamma-ray spectroscopy. The isotopic ratios {sup 151}Sm/{sup 146}Sm, {sup 149}Sm/{sup 146}Sm, and {sup 244}Cm/{sup 246}Cm were found to be good indicators of fuel cycle length and are well suited for analysis by accelerator mass spectroscopy.

Biegalski, S R; Whitney, S M; Buchholz, B

2005-08-24T23:59:59.000Z

150

Surface analysis of rubbers and plastics using secondary neutral mass spectrometry.  

SciTech Connect (OSTI)

Rubber and plastics are complex mixtures of long-chain polymers, smaller organic additives used as plasticizers, mildicides, fungicides, colorants, etc., and inorganic additives such as carbon and silica. Surface analysis of such materials is at once difficult and important. The difficulty lies in the need to identify specific carbon molecules on a very similar organic surface. The importance arises from the dramatic effect that the distribution and concentration of additives have on the physical properties of polymeric materials. Recently we have had some success in applying laser desorption post-ionization mass spectrometry in measuring the surface concentration and distribution of both additives and the polymer molecules themselves. The key has been to use the photoionization properties of the analyte of interest to augment mass spectrometric information.

Pellin, M. J.; Savina, M. R.

1999-08-23T23:59:59.000Z

151

On-line microdialysis sample cleanup for electrospray ionization mass spectrometry of nucleic acid samples  

SciTech Connect (OSTI)

A major limitation of electrospray ionization mass spectrometry (ESI-MS) for oligonucleotide analysis arises due to sodium adduction, a problem that increases with molecular weight. Sodium adduction can preclude useful measurements when limited sample sizes prevent off-line cleanup. A novel and generally useful on-line microdialysis technique is described for the rapid (nearly 1-5 min) DNA sample cleanup for ESI-MS. Mass spectra of oligonucleotides of different size and sequence showing no significant sodium adduct peaks were obtained using the on-line microdialysis system with sodium chloride concentrations as high as 250 mM. Signal-to-noise ratios were also greatly enhanced compared to direct infusion of the original samples. By using ammonium acetate as the dialysis buffer, it was also found that the noncovalent association of double-stranded oligonucleotides could be preserved during the microdialysis process, allowing analysis by ESI-MS. 33 refs., 6 figs.

Liu, C.; Wu, Q.; Harms, A.C.; Smith, R.D. [Pacific Northwest National Lab., Richland, WA (United States)] [Pacific Northwest National Lab., Richland, WA (United States)

1996-09-15T23:59:59.000Z

152

Biases in Ion Transmission Through an Electrospray Ionization-Mass Spectrometry Capillary Inlet  

SciTech Connect (OSTI)

The standard heated capillary inlet of an electrospray ionization mass spectrometry (ESI-MS) interface was compared with shorter versions of the inlet to determine the effects on transmission and ionization efficiencies for low-flow electrosprays. The primary finding of the study was a large bias towards higher mobility species in the electrospray current losses to the inside walls of the inlet. The transmission efficiency increased with decreasing capillary length due to reduced losses along the capillary. A decrease in transmission efficiency was also confirmed for electrosprays of higher conductivity solvents. A direct correlation between mass spectrometry sensitivity and the transmitted electrospray current was not observed as some analytes showed little to no increase in sensitivity while others showed as high as a 15 – fold increase. The variation was shown to at least be partially dependent on the analytes’ mobilities. Higher mobility analytes demonstrated a larger increase in sensitivity when shorter inlets were used. The results indicate that considerable biases against higher mobility species can be produced by the use of long capillary inlets in the ESI-MS interface and strategies are provided to minimize the bias against higher mobility species for efficient ion transmission through the heated capillary interface.

Page, Jason S.; Marginean, Ioan; Baker, Erin Shammel; Kelly, Ryan T.; Tang, Keqi; Smith, Richard D.

2009-12-01T23:59:59.000Z

153

Standard test method for isotopic abundance analysis of uranium hexa?uoride and uranyl nitrate solutions by multi-collector, inductively coupled plasma-mass spectrometry  

E-Print Network [OSTI]

Standard test method for isotopic abundance analysis of uranium hexa?uoride and uranyl nitrate solutions by multi-collector, inductively coupled plasma-mass spectrometry

American Society for Testing and Materials. Philadelphia

2008-01-01T23:59:59.000Z

154

Shotgun Approach for Quantitative Imaging of Phospholipids Using Nanospray Desorption Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

Mass spectrometry imaging (MSI) has been extensively used for determining spatial distributions of molecules in biological samples, and there is increasing interest in using MSI for quantification. Nanospray desorption electrospray ionization, or nano-DESI, is an ambient MSI technique where a solvent is used for localized extraction of molecules followed by nanoelectrospray ionization. Doping the nano-DESI solvent with carefully selected standards enables online quantification during MSI experiments. In this proof-of-principle study, we demonstrate this quantification approach can be extended to provide shotgun-like quantification of phospholipids in thin brain tissue sections. Specifically, two phosphatidylcholine (PC) standards were added to the nano-DESI solvent for simultaneous imaging and quantification of 22 PC species observed in nano-DESI MSI. Furthermore, by combining the quantitative data obtained in the individual pixels, we demonstrate quantification of these PC species in seven different regions of a rat brain tissue section.

Lanekoff, Ingela T.; Thomas, Mathew; Laskin, Julia

2014-02-04T23:59:59.000Z

155

Inductively Coupled Plasma: Fundamental Particle Investigations with Laser Ablation and Applications in Magnetic Sector Mass Spectrometry  

SciTech Connect (OSTI)

Particle size effects and elemental fractionation in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) are investigated with nanosecond and femtosecond laser ablation, differential mobility analysis, and magnetic sector ICP-MS. Laser pulse width was found to have a significant influence on the LA particle size distribution and the elemental composition of the aerosol and thus fractionation. Emission from individual particles from solution nebulization, glass, and a pressed powder pellet are observed with high speed digital photography. The presence of intact particles in an ICP is shown to be a likely source of fractionation. A technique for the online detection of stimulated elemental release from neural tissue using magnetic sector ICP-MS is described. Detection limits of 1 {micro}g L{sup -1} or better were found for P, Mn, Fe, Cu, and Zn in a 60 {micro}L injection in a physiological saline matrix.

Nathan Joe Saetveit

2008-08-18T23:59:59.000Z

156

Characterization of the microdialysis junction interface for capillary electrophoresis/microelectrospray ionization mass spectrometry  

SciTech Connect (OSTI)

A capillary electrophoresis/electrospray ionization mass spectrometry (CE/ESI-MS) interface, based on an electric circuit across a microdialysis membrane surrounding a short capillary segment closely connected to the separation capillary terminus, is demonstrated to be sensitive, efficient, and rugged. A microspray type ionization emitter produces a stable electrospray at the low flow rates provided by CE and thus avoids both the need for a makeup liquid flow provided by liquid junction or sheath flow interfaces and the subsequent dilution and reduction in sensitivity. Reproducibility studies and comparisons with CE/UV and the CE/sheath flow interface with ESI-MS are presented. Additionally, postrun acidification via the microdialysis junction interface is demonstrated and shown to be capable of denaturing the holomyoglobin protein noncovalent complex while maintaining separation efficiency. 21 refs., 7 figs., 1 tab.

Severs, J.C.; Smith, R.D. [Pacific Northwest National Lab., Richland, WA (United States)] [Pacific Northwest National Lab., Richland, WA (United States)

1997-06-01T23:59:59.000Z

157

Characterization of Coordination Complexes by Desorption Electrospray Mass Spectrometry with a Capillary Target  

SciTech Connect (OSTI)

Metal coordination complexes were formed directly from liquid surfaces using desorption electrospray ionization (DESI) mass spectrometry. The approach is attractive because it separates complexities of ESI spray droplet formation from delivery of the analyte solution, and thereby gets around difficulty resulting from alteration of the spray process by changes in solution chemistry. Cs+, Ba2+, and La3+ coordination complexes were formed using 18-crown-6 (18c6) and triethylphosphate (TEP) as ligands (L), that had the general formula [Mn+(NO3-)n-1(L)m]+. Formation of singly charged cation complexes was preferred, with charge reduction at the metal site accomplished by attachment of nitrate. Using TEP as a model phosphoryl ligand, alkali metals coordinate with up to three ligands, with Cs+ preferring fewer than Na+. Ba2+ and La3+ are formed as ion pair complexes [Ba(NO3)]+ and [La(NO3)2]+, and both will coordinate with up to four TEP ligands. Using 18c6, Cs+ forms a bis-ligand complex. In contrast, [Ba(NO3)]+ prefers a single 18c6 ligand, while La forms mainly [La(NO3)2(18c6)]+, for which DFT calculations suggested a structure in which the nitrate ligands occupy pseudo-axial positions on opposing sides of the crown. Lower abundances of bis-18c6 complexes were also formed together with doubly charged [La(NO3)(18c6)n]2+ complexes (n = 2 – 4). The results suggest an alternative strategy for probing metal speciation in solution that is less perturbed by the droplet formation and ionization mechanisms operating in conventional electrospray ionization mass spectrometry.

Gary S. Groenewold; Anthony D. Appelhans; Michael E. McIlwain; Garold L. Gresham

2011-03-01T23:59:59.000Z

158

MAINTAINING HIGH RESOLUTION MASS SPECTROMETRY CAPABILITIES FOR NATIONAL NUCLEAR SECURITY ADMINISTRATION APPLICATIONS  

SciTech Connect (OSTI)

The Department of Energy (DOE) National Nuclear Security Administration (NNSA) has a specialized need for analyzing low mass gas species at very high resolutions. The currently preferred analytical method is electromagnetic sector mass spectrometry. This method allows the NNSA Nuclear Security Enterprise (NSE) to resolve species of similar masses down to acceptable minimum detection limits (MDLs). Some examples of these similar masses are helium-4/deuterium and carbon monoxide/nitrogen. Through the 1980s and 1990s, there were two vendors who supplied and supported these instruments. However, with declining procurements and down turns in the economy, the supply of instruments, service and spare parts from these vendors has become less available, and in some cases, nonexistent. The largest NSE user of this capability is the Savannah River Site (SRS), located near Aiken, South Carolina. The Research and Development Engineering (R&DE) Group in the Savannah River National Laboratory (SRNL) investigated the areas of instrument support that were needed to extend the life cycle of these aging instruments. Their conclusions, as to the focus areas of electromagnetic sector mass spectrometers to address, in order of priority, were electronics, software and hardware. Over the past 3-5 years, the R&DE Group has designed state of the art electronics and software that will allow high resolution legacy mass spectrometers, critical to the NNSA mission, to be operated for the foreseeable future. The funding support for this effort has been from several sources, including the SRS Defense Programs, NNSA Readiness Campaign, Pantex Plant and Sandia National Laboratory. To date, electronics systems have been upgraded on one development system at SRNL, two production systems at Pantex and one production system at Sandia National Laboratory. An NSE working group meets periodically to review strategies going forward. The R&DE Group has also applied their work to the electronics for a Thermal Ionization Mass Spectrometer (TIMS) instrument, which applies a similar mass spectrometric technology for resolving high mass isotopes, such as plutonium and uranium. Due to non-compete clauses for DOE, all work has been performed and applied to instruments which are obsolete and are no longer supported by the original vendor.

Wyrick, S.; Cordaro, J.; Reeves, G.; Mcintosh, J.; Mauldin, C.; Tietze, K.; Varble, D.

2011-06-06T23:59:59.000Z

159

Quantifying Uranium Isotope Ratios Using Resonance Ionization Mass Spectrometry: The Influence of Laser Parameters on Relative Ionization Probability  

SciTech Connect (OSTI)

Resonance Ionization Mass Spectrometry (RIMS) has been developed as a method to measure relative uranium isotope abundances. In this approach, RIMS is used as an element-selective ionization process to provide a distinction between uranium atoms and potential isobars without the aid of chemical purification and separation. We explore the laser parameters critical to the ionization process and their effects on the measured isotope ratio. Specifically, the use of broad bandwidth lasers with automated feedback control of wavelength was applied to the measurement of {sup 235}U/{sup 238}U ratios to decrease laser-induced isotopic fractionation. By broadening the bandwidth of the first laser in a 3-color, 3-photon ionization process from a bandwidth of 1.8 GHz to about 10 GHz, the variation in sequential relative isotope abundance measurements decreased from >10% to less than 0.5%. This procedure was demonstrated for the direct interrogation of uranium oxide targets with essentially no sample preparation. A rate equation model for predicting the relative ionization probability has been developed to study the effect of variation in laser parameters on the measured isotope ratio. This work demonstrates that RIMS can be used for the robust measurement of uranium isotope ratios.

Isselhardt, B H

2011-09-06T23:59:59.000Z

160

Aerosol Mass Spectrometry via Laser-Induced Incandescence Particle Vaporization Final Report  

SciTech Connect (OSTI)

We have successfully developed and commercialized a soot particle aerosol mass spectrometer (SP-AMS) instrument to measure mass, size, and chemical information of soot particles in ambient environments. The SP-AMS instrument has been calibrated and extensively tested in the laboratory and during initial field studies. The first instrument paper describing the SP-AMS has been submitted for publication in a peer reviewed journal and there are several related papers covering initial field studies and laboratory studies that are in preparation. We have currently sold 5 SP-AMS instruments (either as complete systems or as SP modules to existing AMS instrument operators).

Timothy B. Onasch

2011-10-20T23:59:59.000Z

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161

Proceedings of the relevance of mass spectrometry to DNA sequence determination: Research needs for the Human Genome Program  

SciTech Connect (OSTI)

A workshop was sponsored for the US Department of Energy (DOE), Office of Health and Environmental Research by Pacific Northwest Laboratory, April 4--5, 1990, in Seattle, Washington, to examine the potential role of mass spectrometry in the joint DOE/National Institutes of Health (NIH) Human Genome Program. The workshop was occasioned by recent developments in mass spectrometry that are providing new levels for selectivity, sensitivity, and, in particular, new methods of ionization appropriate for large biopolymers such as DNA. During discussions, three general mass spectrometric approaches to the determination of DNA sequence were considered: (1) the mass spectrometric detection of isotopic labels from DNA sequencing mixtures separated using gel electrophoresis, (2) the direct mass spectrometric analysis from direct ionization of unfractionated sequencing mixtures where the measured mass of the constituents functions to identify and order the base sequence (replacing separation by gel electrophoresis), and (3) an approach in which a single highly charged molecular ion of a large DNA segment produced is rapidly sequenced in an ion cyclotron resonance ion trap. The consensus of the workshop was that, on the basis of the new developments, mass spectrometry has the potential to provide the substantial increases in sequencing speed required for the Human Genome Program. 66 refs., 3 tabs.

Edmonds, C.G.; Smith, R.D. (Pacific Northwest Lab., Richland, WA (USA)); Smith, L.M. (Wisconsin Univ., Madison, WI (USA))

1990-11-01T23:59:59.000Z

162

Response of single cells and cell extracts to irradiation as detected by time-of-flight secondary ion mass spectrometry (ToF-SIMS)  

Science Journals Connector (OSTI)

...secondary ion mass spectrometry (ToF-SIMS) Mark G. Knize Kuang Jen Wu David L...Secondary Ion Mass Spectrometry (ToF-SIMS) uses an ion beam to desorb and ionize...Together these experiments show that ToF-SIMS analysis of single cells can be used to...

Mark G. Knize; Kuang Jen Wu; David L. Shattuck; Ligang Wu; Erik J. Nelson; Jennifer L. Montgomery; Cynthia B. Thomas; James S. Felton; Kristen S. Kulp

2005-05-01T23:59:59.000Z

163

Imaging and 3D Elemental Characterization of Intact Bacterial Spores by High-Resolution Secondary Ion Mass Spectrometry  

Science Journals Connector (OSTI)

We present a quantitative, imaging technique based on nanometer-scale secondary ion mass spectrometry for mapping the 3D elemental distribution present in an individual micrometer-sized Bacillus spore. We use depth profile analysis to access the 3D ...

Sutapa Ghosal; Stewart J. Fallon; Terrance J. Leighton; Katherine E. Wheeler; Michael J. Kristo; Ian D. Hutcheon; Peter K. Weber

2008-06-26T23:59:59.000Z

164

Hydrogen-exchange mass spectrometry for the study of intrinsic disorder in proteins Deepa Balasubramaniam, Elizabeth A. Komives  

E-Print Network [OSTI]

Review Hydrogen-exchange mass spectrometry for the study of intrinsic disorder in proteins Deepa 2012 Keywords: Amide exchange Intrinsically disordered proteins Flow quench Amyloid Coupled folding) is seeing wider use for the identification of intrinsically disordered parts of proteins. In this review, we

Komives, Elizabeth A.

165

Method Validation for the Simultaneous Determination of Fecal Sterols in Surface Waters by Gas Chromatography-Mass Spectrometry  

Science Journals Connector (OSTI)

......waters is estimated by gas chromatographic (GC...steroids and endogenous CHL production and metabolism, the sterol...Sterols in Surface Waters by Gas ChromatographyMass Spectrometry...ally quantitated by gas chromatography (GC...characterized. Because cost and time effectiveness......

Sándor Szucs; Attila Sárváry; Terry Cain; Róza Ádány

2006-02-01T23:59:59.000Z

166

Assessment of Non-traditional Isotopic Ratios by Mass Spectrometry for Analysis of Nuclear Activities: Annual Report Year 2  

SciTech Connect (OSTI)

The objective of this work is to identify isotopic ratios suitable for analysis via mass spectrometry that distinguish between commercial nuclear reactor fuel cycles, fuel cycles for weapons grade plutonium, and products from nuclear weapons explosions. Methods will also be determined to distinguish the above from medical and industrial radionuclide sources. Mass spectrometry systems will be identified that are suitable for field measurement of such isotopes in an expedient manner. Significant progress has been made with this project within the past year: (1) Isotope production from commercial nuclear fuel cycles and nuclear weapons fuel cycles have been modeled with the ORIGEN and MCNPX codes. (2) MCNPX has been utilized to calculate isotopic inventories produced in a short burst fast bare sphere reactor (to approximate the signature of a nuclear weapon). (3) Isotopic ratios have been identified that are good for distinguishing between commercial and military fuel cycles as well as between nuclear weapons and commercial nuclear fuel cycles. (4) Mass spectrometry systems have been assessed for analysis of the fission products of interest. (5) A short-list of forensic ratios have been identified that are well suited for use in portable mass spectrometry systems.

Biegalski, S; Buchholz, B

2009-08-26T23:59:59.000Z

167

Statistical prediction of protein–chemical interactions based on chemical structure and mass spectrometry data  

Science Journals Connector (OSTI)

......acid composition n-peptide composition and the derivatives of these...was applied. fDipeptide composition was used in mapping C and...Using pseudo amino acid composition to predict protein structural...studies of drug-likeness, agrochemical-likeness, and enzyme inhibition......

Nobuyoshi Nagamine; Yasubumi Sakakibara

2007-08-01T23:59:59.000Z

168

Combined Atomic Force Microscope-Based Topographical Imaging and Nanometer Scale Resolved Proximal Probe Thermal Desorption/Electrospray Ionization-Mass Spectrometry  

SciTech Connect (OSTI)

Nanometer scale proximal probe thermal desorption/electrospray ionization mass spectrometry (TD/ESI-MS) was demonstrated for molecular surface sampling of caffeine from a thin film using a 30 nm diameter nano-thermal analysis (nano-TA) probe tip in an atomic force microscope (AFM) coupled via a vapor transfer line and ESI interface to a MS detection platform. Using a probe temperature of 350 C and a spot sampling time of 30 s, conical desorption craters 250 nm in diameter and 100 nm deep were created as shown through subsequent topographical imaging of the surface within the same system. Automated sampling of a 5 x 2 array of spots, with 2 m spacing between spots, and real time selective detection of the desorbed caffeine using tandem mass spectrometry was also demonstrated. Estimated from the crater volume (~2x106 nm3), only about 10 amol (2 fg) of caffeine was liberated from each thermal desorption crater in the thin film. These results illustrate a relatively simple experimental setup and means to acquire in automated fashion sub-micrometer scale spatial sampling resolution and mass spectral detection of materials amenable to TD. The ability to achieve MS-based chemical imaging with 250 nm scale spatial resolution with this system is anticipated.

Ovchinnikova, Olga S [ORNL; Nikiforov, Maxim [ORNL; Bradshaw, James A [ORNL; Jesse, Stephen [ORNL; Van Berkel, Gary J [ORNL

2011-01-01T23:59:59.000Z

169

Oxalate Mass Balance During Chemical Cleaning in Tank 5F  

SciTech Connect (OSTI)

The Savannah River Site (SRS) is preparing Tank 5F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning to determine whether the tank is ready for closure. SRS personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. Analysis of the anions showed the measured oxalate removed from Tank 5F to be approximately 50% of the amount added in the oxalic acid. To close the oxalate mass balance, the author collected solid samples, leached them with nitric acid, and measured the concentration of cations and anions in the leachate.

Poirier, M.; Fink, S.

2011-07-08T23:59:59.000Z

170

OXALATE MASS BALANCE DURING CHEMICAL CLEANING IN TANK 6F  

SciTech Connect (OSTI)

The Savannah River Remediation (SRR) is preparing Tank 6F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning to determine whether the tank is ready for closure. SRR personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. Analysis of the anions showed the measured oxalate removed from Tank 6F to be approximately 50% of the amount added in the oxalic acid. To close the oxalate mass balance, the author collected solid samples, leached them with nitric acid, and measured the concentration of cations and anions in the leachate. Some conclusions from this work are: (1) Approximately 65% of the oxalate added as oxalic acid was removed with the decanted liquid. (2) Approximately 1% of the oxalate (added to the tank as oxalic acid) formed precipitates with compounds such as nickel, manganese, sodium, and iron (II), and was dissolved with nitric acid. (3) As much as 30% of the oxalate may have decomposed forming carbon dioxide. The balance does not fully account for all the oxalate added. The offset represents the combined uncertainty in the analyses and sampling.

Poirier, M.; Fink, S.

2011-07-22T23:59:59.000Z

171

Improving boron isotope ratio measurement precision with quadrupole inductively coupled plasma-mass spectrometry  

Science Journals Connector (OSTI)

A method was developed to improve the precision of inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) for the determination of boron isotope ratios (11B/10B) in various environmental materials including seawater. This approach is based on the common analyte internal standardization (CAIS) chemometric algorithm. The sample solution obtained after digestion is spiked with lithium, and both 7Li/6Li and 11B/10B values are measured using long-counting periods (20 min). The CAIS algorithm corrects the measured 11B/10B values for (a) statistical fluctuations resulting from short-term noise; (b) drift in 11B-to-10B ratio as a result of long-term deviation in instrumental parameters likely to occur during long counting times; (c) change in 11B-to-10B ratio caused by variation in matrix elements concentrations; and (d) drift in mass bias correction factor. Comparing boron isotopic ratios in seawater measured by conventional and the new isotope ratio methods validates the procedure. A synthetic isotopic mixture of boron SRM 951 and enriched 10B SRM 952 also was examined. The CAIS method provided a measured boron isotopic ratio precision of 0.05% R.S.D. while eliminating 5.1% matrix concentration error and 0.25% instrumental drift error.

Assad Al-Ammar; Eva Reitznerová; Ramon M. Barnes

2000-01-01T23:59:59.000Z

172

Size Characterization of Colloidal Platinum Nanoparticles by MALDI-TOF Mass Spectrometry  

SciTech Connect (OSTI)

In this work, matrix assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry (MS) has been utilized to characterize colloidal platinum nanoparticles synthesized in the 1-4 nm size range. The nanoparticles were prepared via a solution-based method in which the size could be controlled by varying reaction conditions, such as the alcohol used as the reductant. Poly(vinylpyrrolidone), or PVP, (MW = 29,000 g/mol) was employed as a capping agent to stabilize the synthesized nanoparticles in solution. A model for determining the size of the metallic nanoparticle core from MALDI-TOF mass spectra has been developed and verified through correlation with particle sizes from transmission electron microscopy (TEM) and X-ray diffraction (XRD) measurements. In this model it was assumed that 1.85 nm nanoparticles are capped by one PVP chain, which was verified through experiments performed with capped and uncapped nanoparticles. Larger nanoparticles are capped by either two (2.60 and 2.94 nm) or three (3.69 nm) PVP chains. These findings clearly indicate the usefulness of MALDI-TOF MS as a technique for fully characterizing nanoscale materials in order to elucidate structure-property relationships.

Navin, Jason K.; Grass, Michael E.; Somorjai, Gabor A.; Marsh, Anderson L.

2009-08-15T23:59:59.000Z

173

Observation of a noncovalent ribonuclease S-protein/S-peptide complex by electrospray ionization mass spectrometry  

SciTech Connect (OSTI)

Electrospray ionization mass spectrometry (ESI-MS) investigations of noncovalently-bound complexes are of great interest because of their relevance to solution biochemistry. ESI-MS is particularly well suited to studies of weak interactions because it is very gentle and it allows studies to be performed under physiological or near-physiological solution conditions. However, it is not yet fully understood which weakly-bound complexes known to exist in solution will be observable by ESI-MS, or what minimum binding strength may be required for ESI-MS observation. Also unclear is whether complexes observed by ESI-MS reflect only species present in the bulk solution, or whether complexes also reflect aggregation in electrospray-generated microdroplets. We address some of these issues by employing ribonuclease S (RNase-S) as a test of the applicability of ESI-MS for analysis of noncovalent complexes. These results show that the ESI mass spectra of R Nase-S can reflect the specificity of binding in solution. 33 refs., 2 figs.

Loo, R.R.O.; Goodlett, D.R.; Smith, R.D.; Loo, J.A. (Pacific Northwest Lab., Richland, WA (United States))

1993-05-19T23:59:59.000Z

174

Control of Analyte Electrolysis in Electrospray Ionization Mass Spectrometry Using Repetitively Pulsed High Voltage  

SciTech Connect (OSTI)

Analyte electrolysis using a repetitively pulsed high voltage ion source was investigated and compared to that using a regular, continuously operating direct current high voltage ion source in electrospray ionization mass spectrometry. The extent of analyte electrolysis was explored as a function of the length and frequency of the high voltage pulse using the model compound reserpine in positive ion mode. Using +5 kV as the maximum high voltage amplitude, reserpine was oxidized to its 2, 4, 6 and 8-electron oxidation products when direct current high voltage was employed. In contrast, when using a pulsed high voltage, oxidation of reserpine was eliminated by employing the appropriate high voltage pulse length and frequency. This effect was caused by inefficient mass transport of the analyte to the electrode surface during the duration of the high voltage pulse and the subsequent relaxation of the emitter electrode/ electrolyte interface during the time period when the high voltage was turned off. This mode of ESI source operation allows for analyte electrolysis to be quickly and simply switched on or off electronically via a change in voltage pulse variables.

Kertesz, Vilmos [ORNL; Van Berkel, Gary J [ORNL

2011-01-01T23:59:59.000Z

175

Pyrolysis Gas Chromatography Mass Spectrometry Studies to Evaluate High-Temperature Aqueous Pretreatment as a Way to Modify the Composition of Bio-Oil from Fast Pyrolysis of Wheat Straw  

Science Journals Connector (OSTI)

Pyrolysis Gas Chromatography Mass Spectrometry Studies to Evaluate High-Temperature Aqueous Pretreatment as a Way to Modify the Composition of Bio-Oil from Fast Pyrolysis of Wheat Straw ... ?-Cellulose was obtained from Sigma-Aldrich (St. Louis, Missouri). ... This evidence suggests that CHW pretreatment may produce bio-oil that is composed of a greater amount of sugars and furanics and fewer small molecules and may therefore be a viable option to modify the chemical composition of bio-oils. ...

Robert Lee Johnson; Shi-Shen Liaw; Manuel Garcia-Perez; Su Ha; Sean S.-Y. Lin; Armando G. McDonald; Shulin Chen

2009-10-07T23:59:59.000Z

176

SAMPLING AND MASS SPECTROMETRY APPROACHES FOR THE DETECTION OF DRUGS AND FOREIGN CONTAMINANTS IN BREATH FOR HOMELAND SECURITY APPLICATIONS  

SciTech Connect (OSTI)

Homeland security relies heavily on analytical chemistry to identify suspicious materials and persons. Traditionally this role has focused on attribution, determining the type and origin of an explosive, for example. But as technology advances, analytical chemistry can and will play an important role in the prevention and preemption of terrorist attacks. More sensitive and selective detection techniques can allow suspicious materials and persons to be identified even before a final destructive product is made. The work presented herein focuses on the use of commercial and novel detection techniques for application to the prevention of terrorist activities. Although drugs are not commonly thought of when discussing terrorism, narcoterrorism has become a significant threat in the 21st century. The role of the drug trade in the funding of terrorist groups is prevalent; thus, reducing the trafficking of illegal drugs can play a role in the prevention of terrorism by cutting off much needed funding. To do so, sensitive, specific, and robust analytical equipment is needed to quickly identify a suspected drug sample no matter what matrix it is in. Single Particle Aerosol Mass Spectrometry (SPAMS) is a novel technique that has previously been applied to biological and chemical detection. The current work applies SPAMS to drug analysis, identifying the active ingredients in single component, multi-component, and multi-tablet drug samples in a relatively non-destructive manner. In order to do so, a sampling apparatus was created to allow particle generation from drug tablets with on-line introduction to the SPAMS instrument. Rules trees were developed to automate the identification of drug samples on a single particle basis. A novel analytical scheme was also developed to identify suspect individuals based on chemical signatures in human breath. Human breath was sampled using an RTube{trademark} and the trace volatile organic compounds (VOCs) were preconcentrated using solid phase microextraction (SPME) and identified using gas chromatography - mass spectrometry (GC-MS). Modifications to the sampling apparatus allowed for increased VOC collection efficiency, and reduced the time of sampling and analysis by over 25%. The VOCs are present in breath due to either endogenous production, or exposure to an external source through absorption, inhalation, or ingestion. Detection of these exogenous chemicals can provide information on the prior location and activities of the subject. Breath samples collected before and after exposure in a hardware store and nail salon were analyzed to investigate the prior location of a subject; breath samples collected before and after oral exposure to terpenes and terpenoid compounds, pseudoephedrine, and inhalation exposure to hexamine and other explosive related compounds were analyzed to investigate the prior activity of a subject. The elimination of such compounds from the body was also monitored. In application, this technique may provide an early warning system to identify persons of interest in the prevention and preemption stages of homeland security.

Martin, A N

2009-01-27T23:59:59.000Z

177

Ionization and transmission efficiency in an electrospray ionization-mass spectrometry interface  

SciTech Connect (OSTI)

The efficiency of sample ionization by electrospray ionization (ESI) and the transmission of the charged droplets and gas-phase ions through an ESI interface were investigated in order to advance the understanding of how these factors affect mass spectrometry (MS) sensitivity. In addition, the effects of the ES emitter distance to the inlet, solution flow rate, and inlet temperature to the ionization and transmission efficiency were characterized. Quantitative measurements of ES current loss throughout the ESI interface were accomplished by electrically isolating the front surface of the interface from the inner wall of the heated inlet capillary, enabling losses on the two surfaces to be distinguished. The ES current lost to the front surface of the ESI interface was also spatially profiled with a linear array of 340-µm-dia. electrodes placed adjacent to the inlet capillary entrance. Current transmitted as gas-phase ions was differentiated from charged droplets and solvent clusters by directly measuring sensitivity with a single quadrupole mass spectrometer. The study has revealed a large sampling efficiency into the inlet capillary (>90% at an emitter distance of 1 mm), a global rather than a local gas dynamic effect on the shape of the ES plume due to the gas flow conductance limit of the inlet capillary, a large (>80%) loss of analyte after transmission through the inlet due to incomplete desolvation at a solution flow rate of 1.0 µL/min, and a decrease in analyte peak intensity at lower temperatures, despite a large increase in ES current transmission efficiency. These studies provide a clearer understanding of the parameters affecting ion transmission into the mass spectrometer, and will serve to guide the design of more efficient instrument interfaces.

Page, Jason S.; Kelly, Ryan T.; Tang, Keqi; Smith, Richard D.

2007-09-01T23:59:59.000Z

178

Simultaneous Quantitation of 2-Acetyl-4-tetrahydroxybutylimidazole, 2- and 4-Methylimidazoles, and 5-Hydroxymethylfurfural in Beverages by Ultrahigh-Performance Liquid Chromatography–Tandem Mass Spectrometry  

Science Journals Connector (OSTI)

Simultaneous Quantitation of 2-Acetyl-4-tetrahydroxybutylimidazole, 2- and 4-Methylimidazoles, and 5-Hydroxymethylfurfural in Beverages by Ultrahigh-Performance Liquid Chromatography–Tandem Mass Spectrometry ... An ultrahigh-performance liquid chromatography (UHPLC) tandem mass spectrometric (MS/MS) method was developed for the simultaneous quantification of 2-acetyl-4-tetrahydroxybutylimidazole (THI), 2- and 4-methylimidazoles (2-MI and 4-MI), and 5-hydroxymethylfurfural (HMF) in beverage samples. ... 2-acetyl-4-tetrahydroxybutylimidazole; methylimidazole; 5-hydroxymethylfurfural; carcinogen; beverage; UHPLC; mass spectrometry ...

Jinyuan Wang; William C. Schnute

2011-12-30T23:59:59.000Z

179

Using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) for sensitive cell type differentiation and analysis of paraffin- embedded bladder and prostate tissue sections: Applications for cancer prognosis  

Science Journals Connector (OSTI)

...Secondary Ion Mass Spectrometry (ToF-SIMS) for sensitive cell type differentiation...Secondary Ion Mass Spectrometry (ToF-SIMS), a powerful imaging mass spectrometry...molecular images of the tissues. ToF-SIMS measurements utilize a finely focused primary...

Kristen Kulp; Elena Berman; Susan Fortson; Kuang Jen Wu; Mark Knize; Ligang Wu; Ralph deVere White; Regina Gandour-Edwards; David Seligson; Lee Goodglick; David Chia; Shelia Tze; James Felton

2007-05-01T23:59:59.000Z

180

Detection of Biosignatures by Geomatrix-Assisted Laser Desorption/Ionization (GALDI) Mass Spectrometry  

SciTech Connect (OSTI)

Identification of mineral-associated biosignatures is of significance for retrieving biochemical information from geological records here on Earth and detecting signs of life on other planets, such as Mars. The importance of the geomatrix for identifying amino acids (e.g., histidine, threonine, and cysteine) and small proteins (e.g., gramicidin S) was investigated by laser desorption Fourier transform mass spectrometry. The investigated geomatrices include analogues of Fe-bearing minerals such as hematite and Na-bearing evaporites (e.g., halite). Samples were prepared by two methods: 1) application of analyte to the geomatrix surface and 2) production of homogenous analyte:geomatrix mixtures. Comparison of the two sample preparation methods revealed that the mixing method produces a better signal/noise ratio than surface application for the analyses of amino acids. The composition of the geomatrix has a profound influence on the detection of biomolecules. Peaks corresponding to the cation-attached biomolecular ions were observed for the Na-bearing evaporite analogue. No detectable peaks for the biomolecular ion species were observed when the biomolecules were associated with Fe-bearing minerals. Instead, only minor peaks were observed that may correspond to ions from fragments of the biomolecules. Depending on the underlying mineral composition, geomatrix-assisted laser desorption/ionization shows promise for directly identifying biosignatures associated with minerals.

Jill R. Scott; Beizhan Yan; Daphne L. Stoner; J. Michelle Kotler; Nancy W. Hinman

2007-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Observation of the noncovalent quaternary associations of proteins by electrospray ionization mass spectrometry  

SciTech Connect (OSTI)

The noncovalent tetrameric active forms of avidin, concanavalin A (Con A), and adult human hemoglobin (HbA[sub 0]) can be observed intact in the gas phase by electrospray ionization mass spectrometry (ESI-MS). The atmosphere-vacuum ESI interface conditions strongly influence the retention of these weak noncovalent solution associations into the gas phase, as well as the average extent of charging for the subunits upon dissociation. The known solution pH dependence of the dimer-tetramer equilibrium of Con A was observed by ESI-MS, and the intact heterodimeric and -tetrameric active forms of adult human HbA[sub 0], ([alpha][beta]) and ([alpha][beta])[sub 2], with the prosthetic heme groups could also be characterized by ESI-MS. Under harsher interface conditions a species corresponding to a trimer was observed for each of the proteins, a species not known to be formed under physiological conditions. Differences in the relative stabilities of these tetrameric proteins, formed from the known solution structures, are also qualitatively consistent with the gas-phase stability observed with ESI-MS by adjusting the atmosphere-vacuum interface conditions. The hemoglobin tetramer was found to be less stable in the gas phase than either the Con A or avidin tetramer, consistent with solution dissociation constants. 21 refs., 14 figs.

Light-Wahl, K.J.; Schwartz, B.L.; Smith, R.D. (Pacific Northwest Lab., Richland, WA (United States))

1994-06-15T23:59:59.000Z

182

Determination of long-lived actinides in soil leachates by inductively coupled plasma: Mass spectrometry  

SciTech Connect (OSTI)

Inductively coupled plasma -- mass spectrometry (ICP-MS) was used to concurrently determine multiple long-lived (t{sub 1/2} > 10{sup 4} y) actinide isotopes in soil samples. Ultrasonic nebulization was found to maximize instrument sensitivity. Instrument detection limits for actinides in solution ranged from 50 mBq L{sup {minus}1} ({sup 239}Pu) to 2 {mu}Bq L{sup {minus}1} ({sup 235}U) Hydride adducts of {sup 232}Th and {sup 238}U interfered with the determinations of {sup 233}U and {sup 239} Pu; thus, extraction chromatography was, used to eliminate the sample matrix, concentrate the analytes, and separate uranium from the other actinides. Alpha spectrometric determinations of {sup 230}Th, {sup 239}Pu, and the {sup 234}U/{sup 238}U activity ratio in soil leachates compared well with ICP-MS determinations; however, there were some small systematic differences (ca. 10%) between ICP-MS and a-spectrometric determinations of {sup 234}U and {sup 238}U activities.

Crain, J.S.; Smith, L.L.; Yaeger, J.S.; Alvarado, J.A.

1994-06-01T23:59:59.000Z

183

Molecular beam mass spectrometric characterization of biomass pyrolysis products for fuels and chemicals  

SciTech Connect (OSTI)

Converting biomass feedstocks to fuels and chemicals requires rapid characterization of the wide variety of possible feedstocks. The combination of pyrolysis molecular beam mass spectrometry (Py-MBMS) and multivariate statistical analysis offers a unique capability for characterizing these feedstocks. Herbaceous and woody biomass feedstocks that were harvested at different periods were used in this study. The pyrolysis mass spectral data were acquired in real time on the MBMS, and multivariate statistical analysis (factor analysis) was used to analyze and classify Py-MBMS data into compound classes. The effect of harvest times on the thermal conversion of these feedstocks was assessed from these data. Apart from sericea lespedeza, the influence of harvest time on the pyrolysis products of the various feedstocks was insignificant. For sericea lespedeza, samples harvested before plant defoliation were significantly different from those harvested after defoliation. The defoliated plant samples had higher carbohydrate-derived pyrolysis products than the samples obtained from the foliated plant. Additionally, char yields from the defoliated plant samples were lower than those from the foliated plant samples.

Agblevor, F.A.; Davis, M.F.; Evans, R.J. [National Renewal Energy Lab., Golden, CO (United States)

1994-12-31T23:59:59.000Z

184

A new detector for mass spectrometry: Direct detection of low energy ions using a multi-pixel photon counter  

SciTech Connect (OSTI)

A new type of ion detector for mass spectrometry and general detection of low energy ions is presented. The detector consists of a scintillator optically coupled to a single-photon avalanche photodiode (SPAD) array. A prototype sensor has been constructed from a LYSO (Lu{sub 1.8}Y{sub 0.2}SiO{sub 5}(Ce)) scintillator crystal coupled to a commercial SPAD array detector. As proof of concept, the detector is used to record the time-of-flight mass spectra of butanone and carbon disulphide, and the dependence of detection sensitivity on the ion kinetic energy is characterised.

Wilman, Edward S.; Gardiner, Sara H.; Vallance, Claire [Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Rd, Oxford OX1 3TA (United Kingdom); Nomerotski, Andrei [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Rd, Oxford OX1 3RH (United Kingdom); Turchetta, Renato [Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Brouard, Mark [Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Rd, Oxford OX1 3QZ (United Kingdom)

2012-01-15T23:59:59.000Z

185

Measurement of low radioactivity background in a high voltage cable by high resolution inductively coupled plasma mass spectrometry  

SciTech Connect (OSTI)

The measurement of naturally occurring low level radioactivity background in a high voltage (HV) cable by high resolution inductively coupled plasma mass spectrometry (HR ICP MS) is presented in this work. The measurements were performed at the Chemistry Service of the Gran Sasso National Laboratory. The contributions to the radioactive background coming from the different components of the heterogeneous material were separated. Based on the mass fraction of the cable, the whole contamination was calculated. The HR ICP MS results were cross-checked by gamma ray spectroscopy analysis that was performed at the low background facility STELLA (Sub Terranean Low Level Assay) of the LNGS underground lab using HPGe detectors.

Vacri, M. L. di; Nisi, S.; Balata, M. [Gran Sasso National Laboratory, Chemistry Service, SS 17bis km 18.910, 67100 Assergi (Aq) (Italy)] [Gran Sasso National Laboratory, Chemistry Service, SS 17bis km 18.910, 67100 Assergi (Aq) (Italy)

2013-08-08T23:59:59.000Z

186

Fully Automated Laser Ablation Liquid Capture Sample Analysis using NanoElectrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

RATIONALE: Laser ablation provides for the possibility of sampling a large variety of surfaces with high spatial resolution. This type of sampling when employed in conjunction with liquid capture followed by nanoelectrospray ionization provides the opportunity for sensitive and prolonged interrogation of samples by mass spectrometry as well as the ability to analyze surfaces not amenable to direct liquid extraction. METHODS: A fully automated, reflection geometry, laser ablation liquid capture spot sampling system was achieved by incorporating appropriate laser fiber optics and a focusing lens into a commercially available, liquid extraction surface analysis (LESA ) ready Advion TriVersa NanoMate system. RESULTS: Under optimized conditions about 10% of laser ablated material could be captured in a droplet positioned vertically over the ablation region using the NanoMate robot controlled pipette. The sampling spot size area with this laser ablation liquid capture surface analysis (LA/LCSA) mode of operation (typically about 120 m x 160 m) was approximately 50 times smaller than that achievable by direct liquid extraction using LESA (ca. 1 mm diameter liquid extraction spot). The set-up was successfully applied for the analysis of ink on glass and paper as well as the endogenous components in Alstroemeria Yellow King flower petals. In a second mode of operation with a comparable sampling spot size, termed laser ablation/LESA , the laser system was used to drill through, penetrate, or otherwise expose material beneath a solvent resistant surface. Once drilled, LESA was effective in sampling soluble material exposed at that location on the surface. CONCLUSIONS: Incorporating the capability for different laser ablation liquid capture spot sampling modes of operation into a LESA ready Advion TriVersa NanoMate enhanced the spot sampling spatial resolution of this device and broadened the surface types amenable to analysis to include absorbent and solvent resistant materials.

Lorenz, Matthias [ORNL] [ORNL; Ovchinnikova, Olga S [ORNL] [ORNL; Van Berkel, Gary J [ORNL] [ORNL

2014-01-01T23:59:59.000Z

187

OpenMSI: A High-Performance Web-Based Platform for Mass Spectrometry Imaging  

SciTech Connect (OSTI)

Mass spectrometry imaging (MSI) enables researchers to directly probe endogenous molecules directly within the architecture of the biological matrix. Unfortunately, efficient access, management, and analysis of the data generated by MSI approaches remain major challenges to this rapidly developing field. Despite the availability of numerous dedicated file formats and software packages, it is a widely held viewpoint that the biggest challenge is simply opening, sharing, and analyzing a file without loss of information. Here we present OpenMSI, a software framework and platform that addresses these challenges via an advanced, high-performance, extensible file format and Web API for remote data access (http://openmsi.nersc.gov). The OpenMSI file format supports storage of raw MSI data, metadata, and derived analyses in a single, self-describing format based on HDF5 and is supported by a large range of analysis software (e.g., Matlab and R) and programming languages (e.g., C++, Fortran, and Python). Careful optimization of the storage layout of MSI data sets using chunking, compression, and data replication accelerates common, selective data access operations while minimizing data storage requirements and are critical enablers of rapid data I/O. The OpenMSI file format has shown to provide >2000-fold improvement for image access operations, enabling spectrum and image retrieval in less than 0.3 s across the Internet even for 50 GB MSI data sets. To make remote high-performance compute resources accessible for analysis and to facilitate data sharing and collaboration, we describe an easy-to-use yet powerful Web API, enabling fast and convenient access to MSI data, metadata, and derived analysis results stored remotely to facilitate high-performance data analysis and enable implementation of Web based data sharing, visualization, and analysis.

Rubel, Oliver; Greiner, Annette; Cholia, Shreyas; Louie, Katherine; Bethel, E. Wes; Northen, Trent R.; Bowen, Benjamin P.

2013-10-02T23:59:59.000Z

188

Copyright0 1988by San FranciscoPress,Inc., BOX6800, San Franc&o, CA 94101&fM, USA Laser Microprobe Mass Spectrometry  

E-Print Network [OSTI]

Copyright0 1988by San FranciscoPress,Inc., BOX6800, San Franc&o, CA 94101&fM, USA 10 Laser. Bennett, W. Lauwers, A. Vertes, and R. Gijbels Laser microprobe mass spectrometry (LMMS)em- ploys

Vertes, Akos

189

Laser postionization secondary neutral mass spectrometry in tissue: a powerful tool for elemental and molecular imaging in the development of targeted drugs  

Science Journals Connector (OSTI)

...32 Chandra S, Lorey DRI, Smith DR. Quantitative subcellular secondary ion mass spectrometry (SIMS) imaging of boron-10 and boron-11 isotopes in the same cell delivered by two combined BNCT drugs: in vitro studies on human glioblastoma...

Andrea Wittig; Heinrich F. Arlinghaus; Christian Kriegeskotte; Raymond L. Moss; Klaas Appelman; Kurt W. Schmid; Wolfgang A.G. Sauerwein

2008-07-01T23:59:59.000Z

190

Determination of Depleted Uranium in Urine via Isotope Ratio Measurements Using Large-Bore Direct Injection High Efficiency Nebulizer–Inductively Coupled Plasma Mass Spectrometry  

Science Journals Connector (OSTI)

Inductively coupled plasma mass spectrometry (ICP-MS), coupled with a large-bore direct injection high efficiency nebulizer (LB-DIHEN), was utilized to determine the concentration and...

Westphal, Craig S; McLean, John A; Hakspiel, Shelly J; Jackson, William E; McClain, David E; Montaser, Akbar

2004-01-01T23:59:59.000Z

191

Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry: a Fundamental Shift in the Routine Practice of Clinical Microbiology  

Science Journals Connector (OSTI)

...Desorption Ionization-Time of Flight Mass Spectrometry: a Fundamental Shift in the Routine Practice of Clinical Microbiology Andrew...ability to absorb specific laser wavelengths, resulting in electronic excitation of the matrix. A list of matrices commonly used...

Andrew E. Clark; Erin J. Kaleta; Amit Arora; Donna M. Wolk

2013-07-01T23:59:59.000Z

192

Cluster ion formation during sputtering processes: a complementary investigation by ToF-SIMS and plasma ion mass spectrometry  

Science Journals Connector (OSTI)

Plasma ion mass spectrometry using a plasma process monitor (PPM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) have been complementarily employed to investigate the sputtering and ion formation processes of Al-doped zinc oxide. By comparing the mass spectra, insights on ion formation and relative cross-sections have been obtained: positive ions as measured during magnetron sputtering by PPM are originating from the plasma while those in SIMS start at the surface leading to large differences in the mass spectra. In contrast, negative ions originating at the surface will be accelerated through the plasma sheath. They arrive at the PPM after traversing the plasma nearly collisionless as seen from the rather similar spectra. Hence, it is possible to combine the high mass resolution of ToF-SIMS to obtain insight for separating cluster ions, e.g. Znx and ZnOy, and the energy resolution of PPM to find fragmentation patterns for negative ions. While the ion formation processes during both experiments can be assumed to be similar, differences may arise due to the lower volume probed by SIMS. In the latter case, there is a chance of small target inhomogeneities being able to be enhanced and lower surface temperatures leading to less outgassing and, thus, retention of volatile compounds.

T Welzel; S Mändl; K Ellmer

2014-01-01T23:59:59.000Z

193

Analysis of liquified coal for nitrogenous bases; separation by high performance liquid chromatography and identification by probe microdistillation/mass spectrometry  

E-Print Network [OSTI]

ANALYSIS OF LIQUIFIED COAL FOR NITROGENOUS BASES; SEPARATION BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY AND IDENTIFICATION BY PROBE MICRODISTILLATION/MASS SPECTROMETRY A Thesis by LEONARD ROYCE SCHRONK Submitted to the Graduate College... AND IDENTIFICATION BY PROBE MICRODISTILLATION/MASS SPECTROMETRY A Thesis by LEONARD ROYCE SCHRONK Approved as to style and content by: Co-Charrman o Commlxtte ) (Co-Chazrman o Committee Me er Hea of Department December 1978 ABSTRACT Analysis of Liquified...

Schronk, Leonard Royce

1978-01-01T23:59:59.000Z

194

Intra-ring variability of Cr, As, Cd, and Pb in red oak revealed by secondary ion mass spectrometry: Implications for environmental biomonitoring  

Science Journals Connector (OSTI)

...21). Mass balance studies suggest...000 tons of Cr wastewater into the watershed during...AMU, atomic mass units. (b...two alternative treatments are considered...J ( 1993 ) in Plants as Biomonitors...Activation Analysis Plants chemistry growth...Spectrometry, Mass, Secondary...

D. J. Brabander; N. Keon; R. H. R. Stanley; H. F. Hemond

1999-01-01T23:59:59.000Z

195

DETERMINATION OF 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY  

SciTech Connect (OSTI)

A new method for the determination of {sup 237}Np and Pu isotopes in large soil samples has been developed that provides enhanced uranium removal to facilitate assay by inductively coupled plasma mass spectrometry (ICP-MS). This method allows rapid preconcentration and separation of plutonium and neptunium in large soil samples for the measurement of {sup 237}Np and Pu isotopes by ICP-MS. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via {sup 238}U peak tailing. The method provides enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then transferring Pu to DGA resin for additional purification. The decontamination factor for removal of uranium from plutonium for this method is greater than 1 x 10{sup 6}. Alpha spectrometry can also be applied so that the shorter-lived {sup 238}Pu isotope can be measured successfully. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu and {sup 238}Pu were measured by alpha spectrometry.

Maxwell, S.

2010-07-26T23:59:59.000Z

196

Isotopic tracer studies of oxygen transport through SiO2 films at 1000?°C using secondary ion mass spectrometry  

Science Journals Connector (OSTI)

Dry oxides (?8 ppm H2O) grown on Si(100) at 1000?°C at 1 atm using purified 1 6O2 and purified 1 8O2 were analyzed using secondary ion mass spectrometry.1 8O is observed at the interface in the bulk of the 1 6O oxide and at the surface in agreement with other recent reports. Our results show little lattice diffusion in agreement with Mikkelsen’s work [Appl. Phys. Lett. 4 5 1187 (1984)]. A previous report [J. Electrochem. Soc. 1 3 1 1944 (1984)] of appreciable lattice diffusion is due to higher water content.

C. J. Han; C. R. Helms

1986-01-01T23:59:59.000Z

197

Development of mass spectrometry by high energy focused heavy ion beam: MeV SIMS with 8 MeV Cl7+ beam  

Science Journals Connector (OSTI)

Abstract Particle induced X-ray emission (PIXE) at microprobe of Jožef Stefan Institute is used to measure two-dimensional quantitative elemental maps of biological tissue. To improve chemical and biological understanding of the processes in vivo, supplementary information about chemical bonding and/or molecular distributions could be obtained by heavy-ion induced molecular desorption and a corresponding mass spectroscopy with Time-Of-Flight (TOF) mass spectrometer. As the method combines the use of heavy focused ions in MeV energy range and TOF Secondary Ion Mass Spectrometry, it is denoted as MeV SIMS. At Jožef Stefan Institute, we constructed a linear TOF spectrometer and mount it to our multipurpose nuclear microprobe. A beam of 8 MeV 35Cl7+ could be focused to a diameter of better than 3 ?m × 3 ?m and pulsed by electrostatic deflection at the high-energy side of accelerator. TOF mass spectrometer incorporates an 1 m long drift tube and a double stack microchannel plate (MCP) as a stop detector positioned at the end of the drift path. Secondary ions are focused at MCP using electrostatic cylindrical einzel lens. Time of flight spectra are currently acquired with a single-hit time-to-digital converter. Pulsed ion beam produces a shower of secondary ions that are ejected from positively biased target and accelerated towards MCP. We start our time measurement simultaneously with the start of the beam pulse. Signal of the first ion hitting MCP is used to stop the time measurement. Standard pulses proportional to the time of flight are produced with time to analog converter (TAC) and fed into analog-to-digital converter to obtain a time histogram. To enable efficient detection of desorbed fragments with higher molecular masses, which are of particular interest, we recently implemented a state-of art Field Programmable Gate Array (FPGA)-based multi-hit TOF acquisition. To test the system we used focused 8 MeV 35Cl7+ ion beam with pulse length of 180 ns. Mass resolution of measured SIMS spectra, dominantly determined by the duration of the beam pulse, is in good agreement with resolution estimated from pulse length. With improved high-voltage switching ability that will enable beam pulses with duration of 50 ns, a mass resolution of better than 500 is anticipated.

Luka Jeromel; Zdravko Siketi?; Nina Ogrinc Poto?nik; Primož Vavpeti?; Zdravko Rupnik; Klemen Bu?ar; Primož Pelicon

2014-01-01T23:59:59.000Z

198

In situ mass spectrometric study of pyrite (FeS{sub 2}) thin film deposition with metallorganic chemical vapor deposition  

SciTech Connect (OSTI)

Pyrite, FeS{sub 2}, thin films have been prepared by metallorganic chemical vapor deposition using tert-butyl disulfide (TBDS) and iron(III) acetylacetonate [Fe(acac){sub 3}] as the precursors and H{sub 2} as co-reactant. The reaction mechanism is studied with in situ mass spectrometry. The thermal decomposition of TBDS and Fe(acac){sub 3} has been investigated, as well as the synthesis of FeS{sub 2}. A complicated gas-phase reaction chain occurs in the deposition reaction. In the first 1--2 cm of the deposition zone, thick rough films are formed, but further downstream in the reactor a smooth FeS{sub 2} film is deposited. This remarkable change in morphology is accounted for in the proposed reaction mechanism.

Reijnen, L.; Meester, B.; Goossens, A.; Schoonman, J.

2000-05-01T23:59:59.000Z

199

Isotope correlations for determining the isotopic composition of plutonium produced in research and power reactors using the experimental data obtained by alpha and mass spectrometry  

Science Journals Connector (OSTI)

Correlations have been developed for obtaining the isotopic composition of Pu produced in Indian research (CIRUS, DHRUVA) and power (PHWR) reactors. The experimental data obtained on 238Pu/(239Pu + 240Pu) alpha activity ratio using alpha spectrometry and on 240Pu/239Pu, 241Pu/239Pu, 242Pu/239Pu atom ratios by thermal ionisation mass spectrometry were used for developing isotope correlations.

S.K. Aggarwal; D. Alamelu

2005-01-01T23:59:59.000Z

200

Time-Resolved Molecular Characterization of Limonene/Ozone Aerosol using High-Resolution Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

Molecular composition of limonene/O3 secondary organic aerosol (SOA) was investigated using high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) as a function of reaction time. SOA was generated by ozonation of D-limonene in a reaction chamber and sampled at different time intervals using a cascade impactor. The SOA samples were extracted into acetonitrile and analyzed using a HR-ESI-MS instrument with a resolving power of 100,000 (m/?m). The resulting mass spectra provided detailed information about the extent of oxidation inferred from the O:C ratios, double bond equivalency (DBE) factors, and aromaticity indexes (AI) in hundreds of identified individual SOA species.

Bateman, Adam P.; Nizkorodov, Serguei; Laskin, Julia; Laskin, Alexander

2009-09-09T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Calibration of laser ablation inductively coupled plasma mass spectrometry using dried solution aerosols for the quantitative analysis of solid samples  

SciTech Connect (OSTI)

Inductively coupled plasma mass spectrometry (ICP-MS) has become the method of choice for elemental and isotopic analysis. Several factors contribute to its success. Modern instruments are capable of routine analysis at part per trillion levels with relative detection limits in part per quadrillion levels. Sensitivities in these instruments can be as high as 200 million counts per second per part per million with linear dynamic ranges up to eight orders of magnitude. With standards for only a few elements, rapid semiquantitative analysis of over 70 elements in an individual sample can be performed. Less than 20 years after its inception ICP-MS has shown to be applicable to several areas of science. These include geochemistry, the nuclear industry, environmental chemistry, clinical chemistry, the semiconductor industry, and forensic chemistry. In this introduction, the general attributes of ICP-MS will be discussed in terms of instrumentation and sample introduction. The advantages and disadvantages of current systems are presented. A detailed description of one method of sample introduction, laser ablation, is given. The paper also gives conclusions and suggestions for future work. Chapter 2, Quantitative analysis of solids by laser ablation inductively coupled plasma mass spectrometry using dried solution aerosols for calibration, has been removed for separate processing.

Leach, J.

1999-02-12T23:59:59.000Z

202

Poly(3,4-ethylenedioxypyrrole) Modified Emitter Electrode for Substitution of Homogeneous Redox Buffer Agent Hydroquinone in Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

The electrolysis inherent to the operation of the electrospray ionization (ESI) source used with mass spectrometry (MS) is a well-known attendant effect of generating unipolar spray droplets and may affect the analysis of the analyte of interest. Undesirable electrolysis of an analyte may be prevented by limiting the emitter electrode current and/or the mass transport characteristics of the system. However, these ways to avoid analyte electrolysis may not be applcable in all ESI-MS experiments. For example, in the case of specific nanospray systems (e.g. the wire-in-a-capillary bulk-loaded or chip-based tip-loaded nanospray configurations), the solution flow rate is fixed in the 50-500 nL/min range and the electrode surface to volume ratio is large presenting a very effcient analyte to electrode mass transport configuration. In these situations, control over the interfacial potential of the working electrode via homogeneous or traditional heterogeneous (sacrificial metal) redox buffering is a possible way to prevent analyte electrolysis. However, byproducts of these redox buffering approaches can appear in the mass spectra and/or they can chemically alter the analyte. For example, the main reason for using hydroquinone as a homogeneous redox buffer, in addition to its relatively low oxidation potential, is that neither the original compound nor its oxidation product benzoquinone can be detected directly by ESI-MS. However, benzoquinone can alter analytes with thiol functional groups by reacting with those groups via a 1,4-Michael addition.

Peintler-Krivan, Emese [ORNL; Van Berkel, Gary J [ORNL; Kertesz, Vilmos [ORNL

2010-01-01T23:59:59.000Z

203

Determination of boron traces in rye grass BCR 281 by isotope dilution mass spectrometry  

Science Journals Connector (OSTI)

A method for the isotope dilution mass spectrometric (IDMS) determination of boron in rye grass at the 5 ?g...?1 level has been developed. The mass spectrometric measurements are performed using negative thermal ...

A. Lamberty; V. Holland; A. Verbruggen…

1988-01-01T23:59:59.000Z

204

High Precision Atomic Mass Spectrometry with Applications to Neutrino Physics, Fundamental Constants and Physical Chemistry.  

E-Print Network [OSTI]

?? The Florida State University single-ion cryogenic Penning trap mass spectrometer has been used to precisely measure the masses of the doublets 76Ge/76Se and 74Ge/74Se… (more)

Mount, Brianna Jane

2010-01-01T23:59:59.000Z

205

Isobar separation by time-of-flight mass spectrometry for low-energy radioactive ion beam facilities  

Science Journals Connector (OSTI)

A multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) system for low-energy radioactive ion beam facilities has been developed, which can be used for (i) isobar separation and (ii) direct mass measurements of very short-lived nuclei with half-lives of about 1 ms or longer, and (iii) for identification and diagnosis of the ion beam by mass spectrometry. The system has been designed and simulated, and individual subsystems have been built and characterized experimentally. An injection trap for cooling and bunching of the ion beam has been developed, and cooling times of less than one millisecond have been achieved. The performance of the MR-TOF-MS was characterized using the isobaric doublet of carbon monoxide and nitrogen molecular ions. A mass resolving power of 105 (FWHM) has been obtained even with an uncooled ion population. The separator capabilities of the MR-TOF-MS have been demonstrated by removing either carbon monoxide or nitrogen ions from the beam in a Bradbury-Nielsen Gate after a flight time of 320 ?s. The separation power achieved is thus at least 7000 (FWHM) and increases for longer time-of-flight. An energy buncher stage has been designed that compresses the energy spread of the beam after the separation and facilitates efficient injection of the selected ions into an accumulation trap prior to transfer of the ions to experiments downstream of the MR-TOF-MS.

Wolfgang R. Plaß; Timo Dickel; Ulrich Czok; Hans Geissel; Martin Petrick; Katrin Reinheimer; Christoph Scheidenberger; Mikhail I.Yavor

2008-01-01T23:59:59.000Z

206

Tile-Based Fisher-Ratio Software for Improved Feature Selection Analysis of Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry Data  

SciTech Connect (OSTI)

Two-dimensional (2D) gas chromatography coupled with time-of-flight mass spectrometry (GC × GC – TOFMS) is a highly capable instrumental platform that produces complex and information-rich multi-dimensional chemical data. The complex data can be overwhelming, especially when many samples (of various sample classes) are analyzed with multiple injections for each sample. Thus, the data must be analyzed in such a way to extract the most meaningful information. The pixel-based and peak table-based algorithmic use of Fisher ratios has been used successfully in the past to reduce the multi-dimensional data down to those chemical compounds that are changing between classes relative to those that are not (i.e., chemical feature selection). We report on the initial development of a computationally fast novel tile-based Fisher-ratio software that addresses challenges due to 2D retention time misalignment without explicitly aligning the data, which is a problem for both pixel-based and peak table- based methods. Concurrently, the tile-based Fisher-ratio software maximizes the sensitivity contrast of true positives against a background of potential false positives and noise. To study this software, eight compounds, plus one internal standard, were spiked into diesel at various concentrations. The tile-based F-ratio software was able to discover all spiked analytes, within the complex diesel sample matrix with thousands of potential false positives, in each possible concentration comparison, even at the lowest absolute spiked analyte concentration ratio of 1.06.

Marney, Luke C.; Siegler, William C.; Parsons, Brendon A.; Hoggard, Jamin C.; Wright, Bob W.; Synovec, Robert E.

2013-10-15T23:59:59.000Z

207

E-Print Network 3.0 - accelerator mass spectrometry Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

accelerator mass... ATLAS Argonne Tandem Linear Accelerator System The prime national facility for nuclear structure... , accelerated in the world's first superconducting linear...

208

Consecutive Ion Activation for Top Down Mass Spectrometry:? Improved Protein Sequencing by Nozzle?Skimmer Dissociation  

Science Journals Connector (OSTI)

Mass spectra produced by nozzle?skimmer dissociation (NSD) have been little used in the past for structural characterization. NSD cannot be used on mass-separated ions (MS/MS), and for electrosprayed protein ions, previous NSD spectra showed backbone ...

Huili Zhai; Xuemei Han; Kathrin Breuker; Fred W. McLafferty

2005-08-20T23:59:59.000Z

209

Electrospray ionization–tandem mass spectrometry analysis of phospholipid molecular species from Antarctic and non-Antarctic yeasts  

Science Journals Connector (OSTI)

Abstract High performance liquid chromatography-electrospray ionization tandem mass spectrometry was applied to the comprehensive analysis of phospholipids from seven Antarctic and seven non-Antarctic yeasts. Identification of specific fatty acyl moieties to the sn-1 and sn-2 positions of phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS) and phosphatidylinositol (PI) were determined by relative abundance of fragment ions associated with formation of carboxylate anions and loss of fragment ions as free fatty carboxylic acid and ketene. Modulations with growth temperature in fatty acyl moieties in the sn-1 and sn-2 positions were characterized. Principal component analysis demonstrated that PE, PC and to a lesser extent PS, but not PI, were grouped into three distinct clusters consisting of seven Antarctic yeasts (Cryptococcus victoriae, Holtermanniella wattica, H. nyarrowii, Candida psychrophila, Leucosporidium fellii, Glaciozyma antarctica, Rhodotorula mucilaginosa), four non-Antarctic yeasts (C. albicans, Zygosaccharomyces rouxii, Cr. humicolus, R. mucilaginosa) and three strains of Saccharomyces cerevisiae.

Mohammad Bhuiyan; David Tucker; Kenneth Watson

2014-01-01T23:59:59.000Z

210

Measurement of positional isotope exchange rates in enzyme catalyzed reactions by fast atom bombardment mass spectrometry  

E-Print Network [OSTI]

OF FIGURES Page Figure 1. Fast atom bombardment mass spectra of ANP from acetyl CoA synthetase PIX reactions 25 Figure 2. Fast atom bombardment mass spectra of ATP rath 18 various amounts of 0 Figure 3. Fast atom bombardment mass spectra of ANP from... of this phosphate was the result of P-y bridge to 0-non- bridge PK within the labelled ATP molecule. Through reaction rath diazcmcthane the inorganic phosphate was converted to methyl phosphate. Finally this volatile derivative was analyzed mth gas...

Hilscher, Larry Wayne

2012-06-07T23:59:59.000Z

211

Development of an on-line isotope dilution laser ablation inductively coupled plasma mass spectrometry (LA–ICP-MS) method for determination of boron in silicon wafers  

Science Journals Connector (OSTI)

A method has been developed based on an on-line isotope dilution technique couple with laser ablation/inductively coupled plasma mass spectrometry (LA–ICP-MS), for the determination of boron in p-type silicon wafers. The laser-ablated sample aerosol was mixed on-line with an enriched boron aerosol supplied continuously using a conventional nebulization system. Upon mixing the two aerosol streams, the isotope ratio of boron changed rapidly and was then recorded by the ICP-MS system for subsequent quantification based on the isotope dilution principle. As an on-line solid analysis method, this system accurately quantifies boron concentrations in silicon wafers without the need for an internal or external solid reference standard material. Using this on-line isotope dilution technique, the limit of detection for boron in silicon wafers is 2.8 × 1015 atoms cm?3. The analytical results obtained using this on-line methodology agree well with those obtained using wet chemical digestion methods for the analysis of p-type silicon wafers containing boron concentrations ranging from 1.0 × 1016 to 9.6 × 1018 atoms cm?3.

Chao-Kai Yang; Po-Hsiang Chi; Yong-Chine Lin; Yuh-Chang Sun; Mo-Hsiung Yang

2010-01-01T23:59:59.000Z

212

Identification of volatile butyl rubber thermal-oxidative degradation products by cryofocusing gas chromatography/mass spectrometry (cryo-GC/MS).  

SciTech Connect (OSTI)

Chemical structure and physical properties of materials, such as polymers, can be altered as aging progresses, which may result in a material that is ineffective for its envisioned intent. Butyl rubber formulations, starting material, and additives were aged under thermal-oxidative conditions for up to 413 total days at up to 124 %C2%B0C. Samples included: two formulations developed at Kansas City Plant (KCP) (%236 and %2310), one commercially available formulation (%2321), Laxness bromobutyl 2030 starting material, and two additives (polyethylene AC-617 and Vanax MBM). The low-molecular weight volatile thermal-oxidative degradation products that collected in the headspace over the samples were preconcentrated, separated, and detected using cryofocusing gas chromatography mass spectrometry (cryo-GC/MS). The majority of identified degradation species were alkanes, alkenes, alcohols, ketones, and aldehydes. Observations for Butyl %2310 aged in an oxygen-18 enriched atmosphere (18O2) were used to verify when the source of oxygen in the applicable degradation products was from the gaseous environment rather than the polymeric mixture. For comparison purposes, Butyl %2310 was also aged under non-oxidative thermal conditions using an argon atmosphere.

Smith, Jonell Nicole; White, Michael Irvin; Bernstein, Robert; Hochrein, James Michael

2013-02-01T23:59:59.000Z

213

Principal ComponentAnalysisof Optical EmissionSpectroscopy and MassSpectrometry:Applicationto Reactive Ion Etch  

E-Print Network [OSTI]

of process parameters (i.e., pressure, RF power, and gas mixture) on the optical emission and mass spectra.g., chamber pressure, RF power, and gas flow, while others are internal to the condition of the chamber, e

Shadmehr, Reza

214

Determination of particulate lead using aerosol mass spectrometry: MILAGRO/MCMA-2006 observations  

E-Print Network [OSTI]

We report the first measurements of particulate lead (Pb) from Aerodyne Aerosol Mass Spectrometers, which were deployed in and around Mexico City during the Megacity Initiative: Local and Global Research Observations ...

Salcedo, D.

215

Molecular beam mass spectrometry with tunable vacuum ultraviolet (VUV) synchrotron radiation  

E-Print Network [OSTI]

photoionization efficiency (PIE) curve can be plotted whicha photoionization efficiency curve (PIE) 3.1) Using the ALSto mass. 3.8) To plot a PIE curve, one easy way is to use a

Golan, Amir

2014-01-01T23:59:59.000Z

216

New Mass and Lifetime Measurements of $^{152}$Sm Projectile Fragments with Time-Resolved Schottky Mass Spectrometry  

E-Print Network [OSTI]

The FRS-ESR facilities at GSI provide unique conditions for precision measurements with stored exotic nuclei over a large range in the chart of nuclides. In the present experiment the exotic nuclei were produced via fragmentation of $^{152}$Sm projectiles in a thick beryllium target at 500-600 MeV/u, separated in-flight with the fragment separator FRS, and injected into the storage-cooler ring ESR. Mass and lifetime measurements have been performed with bare and few-electron ions. The experiment and first results will be presented in this contribution.

Yu. A. Litvinov; F. Bosch; H. Geissel; H. Weick; K. Beckert; P. Beller; D. Boutin; C. Brandau; L. Chen; O. Klepper; R. Knöbel; C. Kozhuharov; J. Kurcewicz; S. A. Litvinov; M. Mazzocco; G. Münzenberg; C. Nociforo; F. Nolden; W. Plaß; C. Scheidenberger; M. Steck; B. Sun; M. Winkler

2005-09-15T23:59:59.000Z

217

Phenotypic Detection of Carbapenemase-Producing Enterobacteriaceae by Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry and the Carba NP Test  

Science Journals Connector (OSTI)

...Flight Mass Spectrometry and the Carba NP Test James Knox a Snehal Jadhav b Danielle Sevior...the diagnostic accuracy of the Carba NP test with that of a straightforward matrix-assisted...Using PCR as the reference method, both tests demonstrated a sensitivity of 87% and...

James Knox; Snehal Jadhav; Danielle Sevior; Alex Agyekum; Margaret Whipp; Lynette Waring; Jonathan Iredell; Enzo Palombo

2014-09-03T23:59:59.000Z

218

Interface for the rapid analysis of liquid samples by accelerator mass spectrometry  

DOE Patents [OSTI]

An interface for the analysis of liquid sample having carbon content by an accelerator mass spectrometer including a wire, defects on the wire, a system for moving the wire, a droplet maker for producing droplets of the liquid sample and placing the droplets of the liquid sample on the wire in the defects, a system that converts the carbon content of the droplets of the liquid sample to carbon dioxide gas in a helium stream, and a gas-accepting ion source connected to the accelerator mass spectrometer that receives the carbon dioxide gas of the sample in a helium stream and introduces the carbon dioxide gas of the sample into the accelerator mass spectrometer.

Turteltaub, Kenneth; Ognibene, Ted; Thomas, Avi; Daley, Paul F; Salazar Quintero, Gary A; Bench, Graham

2014-02-04T23:59:59.000Z

219

Hydrothermal Liquefaction Oil and Hydrotreated Product from Pine Feedstock Characterized by Heteronuclear Two-Dimensional NMR Spectroscopy and FT-ICR Mass Spectrometry  

SciTech Connect (OSTI)

Hydrothermal liquefaction (HTL) crude oil and hydrotreated product from pine tree farm waste (forest product residual, FPR) have been analyzed by direct infusion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) in both positive- and negative-ionization modes and high-resolution twodimensional heteronuclear 1H-13C NMR spectroscopy. FT-ICR MS resolves thousands of compounds in complex oils and provides unparalleled compositional details for individual molecules for identification of compound class (heteroatom content), type (number of rings plus double bonds to carbon or double bond equivalents (DBE) and carbon number (degree of alkylation). Heteronuclear 1H-13C NMR spectroscopy provides one-bond and multiple-bond correlations between pairs of 1H and 13C chemical shifts that are characteristic of different organic functional groups. Taken together this information provides a picture of the chemical composition of these oils. Pyrolysis crude oil product from pine wood was characterized for comparison. Generally, pyrolysis oil is comprised of a more diverse distribution of heteroatom classes with higher oxygen number relative to HTL oil as shown by both positive- and negative-ion ESI FT-ICR MS. A total of 300 N1, 594 O1 and 267 O2 compounds were observed as products of hydrotreatment. The relative abundance of N1O1, N1O2, N1O3, N2, N2O1, N2O2 and O3 compounds are reduced to different degrees after hydrotreatment and other higher heteroatom containing species (O4-O10, N1O4, N1O5 and N2O3) are completely removed by hydrotreatment.

Sudasinghe, Nilusha; Cort, John R.; Hallen, Richard T.; Olarte, Mariefel V.; Schmidt, Andrew J.; Schaub, Tanner

2014-12-14T23:59:59.000Z

220

Precise ruthenium fission product isotopic analysis using dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS)  

SciTech Connect (OSTI)

99Tc is a subsurface contaminant of interest at numerous federal, industrial, and international facilities. However, as a mono-isotopic fission product, 99Tc lacks the ability to be used as a signature to differentiate between the different waste disposal pathways that could have contributed to subsurface contamination at these facilities. Ruthenium fission-product isotopes are attractive analogues for the characterization of 99Tc sources because of their direct similarity to technetium with regard to subsurface mobility, and their large fission yields and low natural background concentrations. We developed an inductively coupled plasma mass spectrometry (ICP-MS) method capable of measuring ruthenium isotopes in groundwater samples and extracts of vadose zone sediments. Samples were analyzed directly on a Perkin Elmer ELAN DRC II ICP-MS after a single pass through a 1-ml bed volume of Dowex AG 50W-X8 100-200 mesh cation exchange resin. Precise ruthenium isotopic ratio measurements were achieved using a low-flow Meinhard-type nebulizer and long sample acquisition times (150,000 ms). Relative standard deviations of triplicate replicates were maintained at less than 0.5% when the total ruthenium solution concentration was 0.1 ng/ml or higher. Further work was performed to minimize the impact caused by mass interferences using the dynamic reaction cell (DRC) with O2 as the reaction gas. The aqueous concentrations of 96Mo and 96Zr were reduced by more than 99.7% in the reaction cell prior to injection of the sample into the mass analyzer quadrupole. The DRC was used in combination with stable-mass correction to quantitatively analyze samples containing up to 2-orders of magnitude more zirconium and molybdenum than ruthenium. The analytical approach documented herein provides an efficient and cost-effective way to precisely measure ruthenium isotopes and quantitate total ruthenium (natural vs. fission-product) in aqueous matrixes.

Brown, Christopher F.; Dresel, P. Evan; Geiszler, Keith N.; Farmer, Orville T.

2006-05-09T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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221

Laser vaporization/ionization interface for coupling microscale separation techniques with mass spectrometry  

DOE Patents [OSTI]

The present invention provides a laser-induced vaporization and ionization interface for directly coupling microscale separation processes to a mass spectrometer. Vaporization and ionization of the separated analytes are facilitated by the addition of a light-absorbing component to the separation buffer or solvent. 8 figs.

Yeung, E.S.; Chang, Y.C.

1999-06-29T23:59:59.000Z

222

Combining Laser Ablation/Liquid Phase Collection Surface Sampling and High-Performance Liquid Chromatography Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

This paper describes the coupling of ambient pressure transmission geometry laser ablation with a liquid phase sample collection method for surface sampling and ionization with subsequent mass spectral analysis. A commercially available autosampler was adapted to produce a liquid droplet at the end of the syringe injection needle while in close proximity to the surface to collect the sample plume produced by laser ablation. The sample collection was followed by either flow injection or a high performance liquid chromatography (HPLC) separation of the extracted components and detection with electrospray ionization mass spectrometry (ESI-MS). To illustrate the analytical utility of this coupling, thin films of a commercial ink sample containing rhodamine 6G and of mixed isobaric rhodamine B and 6G dyes on glass microscope slides were analyzed. The flow injection and HPLC/ESI-MS analysis revealed successful laser ablation, capture and, with HPLC, the separation of the two compounds. The ablated circular area was about 70 m in diameter for these experiments. The spatial sampling resolution afforded by the laser ablation, as well as the ability to use sample processing methods like HPLC between the sample collection and ionization steps, makes this combined surface sampling/ionization technique a highly versatile analytical tool.

Ovchinnikova, Olga S [ORNL; Kertesz, Vilmos [ORNL; Van Berkel, Gary J [ORNL

2011-01-01T23:59:59.000Z

223

Cadmium binding studies to the earthworm Lumbricus rubellus metallothionein by electrospray mass spectrometry and circular dichroism spectroscopy  

SciTech Connect (OSTI)

The earthworm Lumbricus rubellus has been found to inhabit cadmium-rich soils and accumulate cadmium within its tissues. Two metallothionein (MT) isoforms (1 and 2) have been identified and cloned from L. rubellus. In this study, we address the metalation status, metal coordination, and structure of recombinant MT-2 from L. rubellus using electrospray ionization mass spectrometry (ESI-MS), UV absorption, and circular dichroism (CD) spectroscopy. This is the first study to show the detailed mass and CD spectral properties for the important cadmium-containing earthworm MT. We report that the 20-cysteine L. rubellus MT-2 binds seven Cd{sup 2+} ions. UV absorption and CD spectroscopy and ESI-MS pH titrations show a distinct biphasic demetalation reaction, which we propose results from the presence of two metal-thiolate binding domains. We propose stoichiometries of Cd{sub 3}Cys{sub 9} and Cd{sub 4}Cys{sub 11} based on the presence of 20 cysteines split into two isolated regions of the sequence with 11 cysteines in the N-terminal and 9 cysteines in the C-terminal. The CD spectrum reported is distinctly different from any other metallothionein known suggesting quite different binding site structure for the peptide.

Ngu, Thanh T. [Department of Chemistry, University of Western Ontario, London, Ont., N6A 5B7 (Canada); Sturzenbaum, Stephen R. [School of Biomedical and Health Sciences, King's College, London, SE1 9NH (United Kingdom); Stillman, Martin J. [Department of Chemistry, University of Western Ontario, London, Ont., N6A 5B7 (Canada)]. E-mail: Martin.Stillman@uwo.ca

2006-12-08T23:59:59.000Z

224

Reduction of plyatomic ion interferences in indictively coupled plasma mass spectrometry with cryogenic desolvation  

SciTech Connect (OSTI)

A desolvation scheme for introducing aqueous and organic samples into an argon inductively coupled plasma is described; the aerosol generated by nebulizer is heated (+140 C) and cooled ({minus}80 C) repeatedly, and the dried aerosol is then injected into the mass spectrometer. Polyatomic ions are greatly suppressed. This scheme was validated with analysis of seawater and urine reference samples. Finally, the removal of organic solvents by cryogenic desolvation was studied.

Alves, L.C.

1993-09-01T23:59:59.000Z

225

Qualitative and quantitative analysis of proteolytically digested glycoproteins by mass spectrometry  

E-Print Network [OSTI]

analytes simultaneously. Examples of mass analyzers include ion traps (3-D or 2-D), triple quadrupole, time of flight (TOF), Fourier transform – ion cyclotron resonance (FT-ICR), 14 and, most recently, the orbitrap.76, 77 Each of these analyzers has... is heated to approximately 200 °C, causing the solvent in the charged droplets to evaporate. A combination of solvent evaporation and Coulombic fission, due to increased space charge effects of the ions in the droplets as evaporation is occurring, allows...

Rebecchi, Kathryn

2011-05-31T23:59:59.000Z

226

Determination of thorium in seawater by neutron activation analysis and mass spectrometry  

SciTech Connect (OSTI)

The recent development of neutron activation analysis and mass spectrometric methods for the determination of /sup 232/Th in seawater has made possible rapid sampling and analysis of this long-lived, non-radiogenic thorium isotope on small-volume samples. The marine geochemical utility of /sup 232/Th, whose concentration in seawater is extremely low, warrants the development of these sensitive techniques. The analytical methods and some results are presented and discussed in this article. 24 refs., 3 figs.

Huh, Chih-An

1987-01-01T23:59:59.000Z

227

Direct Surface Analysis of Time-Resolved Aerosol Impactor Samples with Ultrahigh-Resolution Mass Spectrometry  

E-Print Network [OSTI]

.; Pan, Y.; Mitloehner, F. M. Atmos. Environ. 2012, Submitted. (21) Lundgren, D. A. Journal of the Air Pollution Control Association 1967, 17, 225-9. (22) Schultz, G. A.; Corso, T. N.; Prosser, S. J.; Zhang, S. Anal. Chem. 2000, 72, 4058-4063. 19... in negative health effects caused by air pollution and are linked to increases in respiratory and cardio-vascular diseases2,3. All these particle effects are influenced by the chemical composition of the aerosol particles. A major fraction, often more than 50...

Fuller, Stephen J.; Zhao, Yongjing; Cliff, Steven S.; Wexler, Anthony S.; Kalberer, Markus

2012-10-18T23:59:59.000Z

228

Inductively Coupled Plasma Mass Spectrometry and Atomic Emission Spectrometry Coupled to High-Performance Liquid Chromatography for Speciation and Detection of Organotin Compounds  

Science Journals Connector (OSTI)

......graphite furnace atomic absorption ( G F A A ) , flame atomic...fluent is monitored by atomic absorption (20-22). In this study...8 C with a re frigerated chiller (Neslab Instrument, Inc...gas chromatography atomic absorption spectrometry. Anal. Chem......

Hamzar Suyani; John Creed; Tim Davidson; Joseph Caruso

1989-03-01T23:59:59.000Z

229

Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade aluminum oxide and aluminum oxide-boron carbide composite pellets  

E-Print Network [OSTI]

1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade aluminum oxide and aluminum oxide-boron carbide composite pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Boron by Titrimetry 7 to 13 Separation of Boron for Mass Spectrometry 14 to 19 Isotopic Composition by Mass Spectrometry 20 to 23 Separation of Halides by Pyrohydrolysis 24 to 27 Fluoride by Ion-Selective Electrode 28 to 30 Chloride, Bromide, and Iodide by Amperometric Microtitrimetry 31 to 33 Trace Elements by Emission Spectroscopy 34 to 46 1.3 The values stated in SI units are to be regarded as the standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (F...

American Society for Testing and Materials. Philadelphia

1994-01-01T23:59:59.000Z

230

Secondary ion mass spectrometry and Raman spectroscopy for tissue engineering applications  

Science Journals Connector (OSTI)

Identifying the matrix properties that permit directing stem cell fate is crucial for expanding desired cell lineages ex vivo for disease treatment. Such efforts require knowledge of matrix surface chemistry and the cell responses they elicit. Recent progress in analyzing biomaterial composition and identifying cell phenotype with two label-free chemical imaging techniques, TOF-SIMS and Raman spectroscopy are presented. TOF-SIMS is becoming indispensable for the surface characterization of biomaterial scaffolds. Developments in TOF-SIMS data analysis enable correlating surface chemistry with biological response. Advances in the interpretation of Raman spectra permit identifying the fate decisions of individual, living cells with location specificity. Here we highlight this progress and discuss further improvements that would facilitate efforts to develop artificial scaffolds for tissue regeneration.

Yelena Ilin; Mary L Kraft

2015-01-01T23:59:59.000Z

231

Determination of Boron in Coal Using Closed-Vessel Microwave Digestion and Inductively Coupled Plasma Mass Spectrometry (ICP-MS)  

Science Journals Connector (OSTI)

Previous studies indicate that boron in coal has been mostly determined by atomic emission spectroscopy (AES) or inductively coupled plasma–atomic emission spectrometry (ICP-AES). ... The results (Figure 1) indicated that a 2% ammonia solution can effectively eliminate the boron memory effect and reduce boron signals to blank levels (within 120 s), similar to analytical results obtained by Al-Ammar et al.(54) and Huang et al.(55) The boron memory effect is not attributed to the skimmer, sampler, or other mass spectrometer components, but originates from the tendency of boron to volatilize as boric acid from the sample solution that covers the inside surface of the ICP-MS spray chamber. ... Using different online additions of internal standard solutions, the observed boron concentrations based on the 10B and 11B spectral lines are close to each other, indicating that the observed boron concentrations based on the two isotope spectral lines are both suitable for determination of boron in coal. ...

Shifeng Dai; Weijiao Song; Lei Zhao; Xiao Li; James C. Hower; Colin R. Ward; Peipei Wang; Tian Li; Xin Zheng; Vladimir V. Seredin; Panpan Xie; Qingqian Li

2014-06-23T23:59:59.000Z

232

Electrospray mass spectrometry of NeuAc oligomers associated with the C fragment of the tetanus toxin  

SciTech Connect (OSTI)

The Clostridial neurotoxins, botulinum and tetanus, gain entry into neuronal cells by protein recognition involving cell specific binding sites. The sialic or N-acetylneuraminic acid (NeuAc) residues of gangliosides attached to the surface of motor neurons are the suspected recognition and interaction points with Clostridial neurotoxins, although not necessarily the only ones. We have used electrospray ionization mass spectrometry (ESIMS) to examine formation of complexes between the tetanus toxin C fragment, or targeting domain, and carbohydrates containing NeuAc groups to determine how NeuAc residues contribute to ganglioside binding. ESI-MS was used to rapidly and efficiently measure dissociation constants for a number of related NeuAc-containing carbohydrates and NeuAc oligomers, information that has helped identify the structural features of gangliosides that determine their binding to tetanus toxin. The strength of the interactions between the C fragment and (NeuAc){sub n}, are consistent with the topography of the targeting domain of tetanus toxin and the nature of its carbohydrate binding sites. The results suggest that the targeting domain of tetanus toxin contains two binding sites that can accommodate NeuAc (or a dimer). This study also shows that NeuAc must play an important role in ganglioside binding and molecular recognition, a process critical for normal cell function and one frequently exploited by toxins, bacteria and viruses to facilitate their entrance into cells.

Prieto, M C; Whittal, R M; Baldwin, M A; Burlingame, A L; Balhorn, R

2005-04-03T23:59:59.000Z

233

Determination of secondary ion mass spectrometry relative sensitivity factors for polar and non-polar ZnO  

SciTech Connect (OSTI)

Zinc oxide (ZnO) is regarded as a promising material for optoelectronic devices, due to its electronic properties. Solely, the difficulty in obtaining p-type ZnO impedes further progress. In this connection, the identification and quantification of impurities is a major demand. For quantitative information using secondary ion mass spectrometry (SIMS), so-called relative sensitivity factors (RSF) are mandatory. Such conversion factors did not yet exist for ZnO. In this work, we present the determined RSF values for ZnO using primary (ion implanted) as well as secondary (bulk doped) standards. These RSFs have been applied to commercially available ZnO substrates of different surface termination (a-plane, Zn-face, and O-face) to quantify the contained impurities. Although these ZnO substrates originate from the same single-crystal, we observe discrepancies in the impurity concentrations. These results cannot be attributed to surface termination dependent RSF values for ZnO.

Laufer, Andreas; Volbers, Niklas; Eisermann, Sebastian; Meyer, Bruno K. [Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany); Potzger, Kay [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden (Germany); Geburt, Sebastian; Ronning, Carsten [Institut fuer Festkoerperphysik, Universitaet Jena, Max-Wien-Platz 1, 07743 Jena (Germany)

2011-11-01T23:59:59.000Z

234

Standard test method for determination of impurities in nuclear grade uranium compounds by inductively coupled plasma mass spectrometry  

E-Print Network [OSTI]

1.1 This test method covers the determination of 67 elements in uranium dioxide samples and nuclear grade uranium compounds and solutions without matrix separation by inductively coupled plasma mass spectrometry (ICP-MS). The elements are listed in Table 1. These elements can also be determined in uranyl nitrate hexahydrate (UNH), uranium hexafluoride (UF6), triuranium octoxide (U3O8) and uranium trioxide (UO3) if these compounds are treated and converted to the same uranium concentration solution. 1.2 The elements boron, sodium, silicon, phosphorus, potassium, calcium and iron can be determined using different techniques. The analyst's instrumentation will determine which procedure is chosen for the analysis. 1.3 The test method for technetium-99 is given in Annex A1. 1.4 The values stated in SI units are to be regarded as standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish ...

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

235

Characterization of a Sealed Americium-Beryllium (AmBe) Source by Inductively Coupled Plasma Mass Spectrometry  

SciTech Connect (OSTI)

Two Americium-Beryllium neutron sources were dismantled, sampled (sub-sampled) and analyzed via inductively coupled plasma mass spectrometry (ICP-MS). Characteristics such as “age” since purification, actinide content, trace metal content and inter and intra source composition were determined. The “age” since purification of the two sources was determined to be 25.0 and 25.4 years, respectively. The systematic errors in the “age” determination were ± 4 % 2s. The amount and isotopic composition of U and Pu varied substantially between the sub-samples of Source 2 (n=8). This may be due to the physical means of sub-sampling or the way the source was manufactured. Source 1 was much more consistent in terms of content and isotopic composition (n=3 sub-samples). The Be-Am ratio varied greatly between the two sources. Source 1 had an Am-Be ratio of 6.3 ± 52 % (1s). Source 2 had an Am-Be ratio of 9.81 ± 3.5 % (1s). In addition, the trace element content between the samples varied greatly. Significant differences were determined between Source 1 and 2 for Sc, Sr, Y, Zr, Mo, Ba and W.

James Sommers; Marcos Jimenez; Mary Adamic; Jeffrey Giglio; Kevin Carney

2009-12-01T23:59:59.000Z

236

Observation of a small oligonucleotide duplex by electrospray ionization mass spectrometry  

SciTech Connect (OSTI)

Electrospray ionization (ESI) has been demonstrated to be a soft ionization technique, allowing accurate molecular weight determination for biopolymers due to gas-phase multiple charging. Recent results have demonstrated that noncovalent associations can be preserved upon transfer into the gas phase with ESI, providing a new approach to the determination of both structurally-specific and nonspecific noncovalent associations in solution. The mass spectrometric experimental conditions necessary to preserve such noncovalent associations, and the physical constraints upon such, have yet to be elucidated, although it is clear that gentle interface conditions minimizing internal excitation of noncovalent complexes are helpful. Base-paired oligonucleotide hybridization constitutes one of the most important and thoroughly studied noncovalent associations of biopolymers. Initial attempts to observe duplex oligonucleotides resulted in detection of only the monomeric constituents. Since then, the authors have developed interface conditions that are more gentle and yet still provide sufficient molecular ion desolvation to preserve such associations using new instrumentation with a greatly extended m/z range. In this communication, the authors report the successful ionization of duplex oligonucleotides and the conditions necessary for detection by negative ion ESI-MS. 6 refs., 1 fig.

Light-Wahl, K.J.; Springer, D.L.; Winger, B.E.; Edmonds, C.G.; Thrall, B.D.; Smith, R.D. (Pacific Northwest Lab., Richland, WA (United States)); Camp, D.G. II (Eastern Oregon State College, La Grande (United States))

1993-01-27T23:59:59.000Z

237

1,5-Diaminonaphthalene Hydrochloride Assisted Laser Desorption/Ionization Mass Spectrometry Imaging of Small Molecules in Tissues Following Focal Cerebral Ischemia  

Science Journals Connector (OSTI)

In the present study, 1,5-naphthalenediamine (1,5-DAN) hydrochloride was prepared for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) of small molecules in liver, brain, and kidneys from mice. ... Rat brains were removed and immediately frozen under ?80 °C. ... In this study, we conducted IMS on rat brains damaged by ischemic injury and detected various phospholipids that showed unique distributions between normal and damaged areas of the brain. ...

Huihui Liu; Rui Chen; Jiyun Wang; Suming Chen; Caiqiao Xiong; Jianing Wang; Jian Hou; Qing He; Ning Zhang; Zongxiu Nie; Lanqun Mao

2014-09-23T23:59:59.000Z

238

Standard test method for isotopic analysis of hydrolyzed uranium hexafluoride and uranyl nitrate solutions by thermal ionization mass spectrometry  

E-Print Network [OSTI]

1.1 This method applies to the determination of isotopic composition in hydrolyzed nuclear grade uranium hexafluoride. It covers isotopic abundance of 235U between 0.1 and 5.0 % mass fraction, abundance of 234U between 0.0055 and 0.05 % mass fraction, and abundance of 236U between 0.0003 and 0.5 % mass fraction. This test method may be applicable to other isotopic abundance providing that corresponding standards are available. 1.2 This test method can apply to uranyl nitrate solutions. This can be achieved either by transforming the uranyl nitrate solution to a uranyl fluoride solution prior to the deposition on the filaments or directly by depositing the uranyl nitrate solution on the filaments. In the latter case, a calibration with uranyl nitrate standards must be performed. 1.3 This test method can also apply to other nuclear grade matrices (for example, uranium oxides) by providing a chemical transformation to uranyl fluoride or uranyl nitrate solution. 1.4 This standard does not purport to address al...

American Society for Testing and Materials. Philadelphia

2005-01-01T23:59:59.000Z

239

Chemical Reaction of Metal-Carbon Binary Cluster Anions by FT-ICR Mass Spectrometer  

E-Print Network [OSTI]

45 48 51 54 57 60 Number of Carbon Atoms Intensity(arbitrary) (a) as injected (b) SWIFTed (c) NO 1sChemical Reaction of Metal-Carbon Binary Cluster Anions by FT-ICR Mass Spectrometer S. Maruyama, M- fullerene and single walled carbon nanotubes are investigated through experimental studies of interaction

Maruyama, Shigeo

240

Accurate and Precise Determination of Boron Isotopic Ratios at Low Concentration by Positive Thermal Ionization Mass Spectrometry Using Static Multicollection of Cs2BO2+ Ions  

Science Journals Connector (OSTI)

Accurate and Precise Determination of Boron Isotopic Ratios at Low Concentration by Positive Thermal Ionization Mass Spectrometry Using Static Multicollection of Cs2BO2+ Ions ... (1) A relatively large mass difference (10%) between the two isotopes and high volatility results in significant boron isotopic variation from ?70‰(2) to +75‰(3) in natural materials; thus, boron isotopes have numerous applications in geochemistry, isotope hydrology, oceanography, environmental sciences, cosmology, and nuclear technology. ... (2) Our method provided better long-term stability of NIST 951 standard compared to “Zoom Quad” mode when more than two isotopes were determined in addition to boron isotope. ...

Mao-yong He; Ying-kai Xiao; Zhang-dong Jin; Yun-qi Ma; Jun Xiao; Yan-ling Zhang; Chong-guang Luo; Fei Zhang

2013-05-29T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Mass spectrometry in biomarker applications: from untargeted discovery to targeted verification, and implications for platform convergence and clinical application  

SciTech Connect (OSTI)

It is really only in the last ten years that mass spectrometry (MS) has had a truly significant (but still small) impact on biomedical research. Much of this impact can be attributed to proteomics and its more basic applications. Early biomedical applications have included a number of efforts aimed at developing new biomarkers; however, the success of these endeavors to date have been quite modest - essentially confined to preclinical applications - and have often suffered from combinations of immature technology and hubris. Now that MS-based proteomics is reaching adolescence, it is appropriate to ask if and when biomarker-related applications will extend to the clinical realm, and what developments will be essential for this transition. Biomarker development can be described as a multistage process consisting of discovery, qualification, verification, research assay optimization, validation, and commercialization (1). From a MS perspective, it is possible to 'bin' measurements into 1 of 2 categories - those aimed at discovering potential protein biomarkers and those seeking to verify and validate biomarkers. Approaches in both categories generally involve digesting proteins (e.g., with trypsin) as a first step to yield peptides that can be effectively detected and identified with MS. Discovery-based approaches use broad 'unbiased' or 'undirected' measurements that attempt to cover as many proteins as possible in the hope of revealing promising biomarker candidates. A key challenge with this approach stems from the extremely large dynamic range (i.e., relative stoichiometry) of proteins of potential interest in biofluids such as plasma and the expectation that biomarker proteins of the greatest clinical value for many diseases may very well be present at low relative abundances (2). Protein concentrations in plasma extend from approximately 10{sup 10} pg/mL for albumin to approximately 10 pg/mL and below for interleukins and other cytokines.

Smith, Richard D.

2012-03-01T23:59:59.000Z

242

18O-Labeled Proteome Reference as Global Internal Standards for Targeted Quantification by Selected Reaction Monitoring-Mass Spectrometry  

SciTech Connect (OSTI)

Selected reaction monitoring-mass spectrometry (SRM-MS) is an emerging technology for high throughput targeted protein quantification and verification in biological and biomarker discovery studies; however, the cost associated with the use of stable isotope labeled synthetic peptides as internal standards is prohibitive for quantitatively screening large numbers of candidate proteins as often required in the pre-verification phase of biomarker discovery. Herein we present the proof-of-concept experiments of using an 18O-labeled 'universal' reference as comprehensive internal standards for quantitative SRM-MS analysis. With an 18O-labeled whole proteome sample as reference, every peptide of interest will have its own corresponding heavy isotope labeled internal standard, thus providing an ideal approach for quantitative screening of a large number of candidates using SRM-MS. Our results showed that the 18O incorporation efficiency using a recently improved protocol was >99.5% for most peptides investigated, a level comparable to 13C/15N labeled synthetic peptides in terms of heavy isotope incorporation. The accuracy, reproducibility, and linear dynamic range of quantification were further assessed based on known ratios of standard proteins spiked into mouse plasma with an 18O-labeled mouse plasma reference. A dynamic range of four orders of magnitude in relative concentration was obtained with high reproducibility (i.e., coefficient of variance <10%) based on the 16O/18O peak area ratios. Absolute and relative quantification of C-reactive protein and prostate-specific antigen were demonstrated by coupling an 18O-labeled reference with standard additions of protein standards. Collectively, our results demonstrated that the use of 18O-labeled reference provides a convenient and effective strategy for quantitative SRM screening of large number of candidate proteins.

Kim, Jong Seo; Fillmore, Thomas L.; Liu, Tao; Robinson, Errol W.; Hossain, Mahmud; Champion, Boyd L.; Moore, Ronald J.; Camp, David G.; Smith, Richard D.; Qian, Weijun

2011-10-11T23:59:59.000Z

243

Periostin, discovered by nano-flow liquid chromatography and mass spectrometry, is a novel marker of diabetic retinopathy  

SciTech Connect (OSTI)

Research highlights: {yields} In proliferative membrane and epiretinal membrane specimens, the numbers of proteins are 225 and 154, respectively, and 123 proteins are common to both. {yields} Periostin and thrombospondin-1 proteins are unique to the proliferative membrane specimens. {yields} The expression of periostin is significantly up-regulated in proliferative membrane specimens. -- Abstract: Diabetes can lead to serious microvascular complications including proliferative diabetic retinopathy (PDR), the leading cause of blindness in adults. Recent studies using gene array technology have attempted to apply a hypothesis-generating approach to elucidate the pathogenesis of PDR, but these studies rely on mRNA differences, which may or may not be related to significant biological processes. To better understand the basic mechanisms of PDR and to identify potential new biomarkers, we performed shotgun liquid chromatography (LC)/tandem mass spectrometry (MS/MS) analysis on pooled protein extracts from neovascular membranes obtained from PDR specimens and compared the results with those from non-vascular epiretinal membrane (ERM) specimens. We detected 226 distinct proteins in neovascular membranes and 154 in ERM. Among these proteins, 102 were specific to neovascular membranes and 30 were specific to ERM. We identified a candidate marker, periostin, as well as several known PDR markers such as pigment epithelium-derived factor (PEDF). We then performed RT-PCR using these markers. The expression of periostin was significantly up-regulated in proliferative membrane specimens. Periostin induces cell attachment and spreading and plays a role in cell adhesion. Proteomic analysis by LC/MS/MS, which permits accurate quantitative comparison, was useful in identifying new candidates such as periostin potentially involved in the pathogenesis of PDR.

Takada, Michiya [Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Showa University School of Medicine, Tokyo (Japan)] [Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Showa University School of Medicine, Tokyo (Japan); Ban, Yoshiyuki, E-mail: yshyban@yahoo.co.jp [Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Showa University School of Medicine, Tokyo (Japan)] [Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Showa University School of Medicine, Tokyo (Japan); Yamamoto, Gou [Department of Oral Pathology and Diagnosis, School of Dentistry, Showa University, Tokyo (Japan)] [Department of Oral Pathology and Diagnosis, School of Dentistry, Showa University, Tokyo (Japan); Ueda, Toshihiko; Saito, Yuta; Nishimura, Eiichi; Fujisawa, Kunimi; Koide, Ryohei [Department of Ophthalmology, Showa University School of Medicine, Tokyo (Japan)] [Department of Ophthalmology, Showa University School of Medicine, Tokyo (Japan); Mizutani, Masakazu; Kozawa, Tadahiko; Shiraishi, Yuji [Kozawa Eye Hospital and Diabetes Center, Ibaraki-ken (Japan)] [Kozawa Eye Hospital and Diabetes Center, Ibaraki-ken (Japan); Bando, Yasuhiko [Biosys Technologies, Inc., Meguro, Tokyo (Japan)] [Biosys Technologies, Inc., Meguro, Tokyo (Japan); Tachikawa, Tetsuhiko [Department of Oral Pathology and Diagnosis, School of Dentistry, Showa University, Tokyo (Japan)] [Department of Oral Pathology and Diagnosis, School of Dentistry, Showa University, Tokyo (Japan); Hirano, Tsutomu [Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Showa University School of Medicine, Tokyo (Japan)] [Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Showa University School of Medicine, Tokyo (Japan)

2010-08-20T23:59:59.000Z

244

A High-Performance Liquid Chromatographic-Atmospheric Pressure Chemical Ionization-Tandem Mass Spectrometric Method for Determination of Risperidone and 9-Hydroxyrisperidone in Human Plasma  

Science Journals Connector (OSTI)

......Chromatographic-Atmospheric Pressure Chemical...9-Hydroxyrisperidone in Human Plasma David E. Moody...spec- trometry and atmospheric pressure chemical...or polar drugs in plasma. Ther. Drug Monit...their metabolites in plasma by liquid chromatography...spectrometry with atmospheric pres- sure chemical......

David E. Moody; John D. Laycock; Wei Huang; Rodger L. Foltz

2004-09-01T23:59:59.000Z

245

E-Print Network 3.0 - absorption spectrometry etaas Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

With Confirmation of Accuracy by Inductively Coupled Plasma Mass Spectrometry and Atomic Absorption Spectrometry... -LEAFS uses absorption; graphite furnace; inductively...

246

Real-time monitoring of volatile organic compounds using chemical ionization mass spectroscopy: Final report  

SciTech Connect (OSTI)

Volatile organic compound (VOC) emission to the atmosphere is of great concern to semiconductor manufacturing industries, research laboratories, the public, and regulatory agencies. Some industries are seeking ways to reduce emissions by reducing VOCs at the point of use (or generation). This paper discusses the requirements, design, calibration, and use of a sampling inlet/quadrupole mass spectrometer system for monitoring VOCs in a semiconductor manufacturing production line. The system uses chemical ionization to monitor compounds typically found in the lithography processes used to manufacture semiconductor devices (e.g., acetone, photoresist). The system was designed to be transportable from tool to tool in the production line and to give the operator real-time feedback so the process(es) can be adjusted to minimize VOC emissions. Detection limits ranging from the high ppb range for acetone to the low ppm range fore other lithography chemicals were achieved using chemical ionization mass spectroscopy at a data acquisition rate of approximately 1 mass spectral scan (30 to 200 daltons) per second. A demonstration of exhaust VOC monitoring was performed at a working semiconductor fabrication facility during actual wafer processing.

Thornberg, S.M.; Mowry, C.D.; Keenan, M.R.; Bender, S.F.A. [Sandia National Labs., Albuquerque, NM (United States). Gas Analysis Lab.; Owen, T. [Intel Corp., Rio Rancho, NM (United States)

1997-04-01T23:59:59.000Z

247

Real-Time, On-Line Characterization of Diesel Generator Air Toxic Emissions by Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry  

Science Journals Connector (OSTI)

Real-Time, On-Line Characterization of Diesel Generator Air Toxic Emissions by Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry ... For the same reasons, the far more abundant exhaust gases such as nitrogen, water, and carbon dioxide cannot be ionized and, therefore, do not interfere with the potential detection of low (2?100 pptv) concentrations of organic molecules. ... The sample was introduced into the ionization chamber (Figure 1) through a modified pulsed valve (General Valve Series 99) that delivers 150-?s sample pulses at atmospheric back pressure through a 0.5-mm orifice at a repetition rate of 10 Hz. ...

Lukas Oudejans; Abderrahmane Touati; Brian K. Gullett

2004-03-24T23:59:59.000Z

248

Real-Time Quantitative Analysis of Combustion-Generated Polycyclic Aromatic Hydrocarbons by Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry  

Science Journals Connector (OSTI)

Real-Time Quantitative Analysis of Combustion-Generated Polycyclic Aromatic Hydrocarbons by Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry ... Field data1 suggest that naphthalene, fluorene, and anthracene are among the most abundant PAH products of incomplete hydrocarbon production. ... The sample transfer line is 6.35 mm diameter, quartz-lined stainless steel tubing (Alltech, Deerfield, IL) that is heated to 250?300 °C using flexible cable heaters (Omega Engineering, Stamford, CT). Care is taken to uniformly heat the sample transfer line, since the efficiency of the line is reduced dramatically by the presence of cold spots. ...

Christopher M. Gittins; Marco J. Castaldi; Selim M. Senkan; Eric A. Rohlfing

1997-02-01T23:59:59.000Z

249

Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry of coal liquids produced during a coal liquefaction process  

SciTech Connect (OSTI)

Comprehensive two-dimensional gas chromatography (GC) coupled to time-of-flight mass spectrometry (MS) has been applied to the analysis of coal-derived liquids from the former British Coal Point-of-Ayr coal liquefaction plant. The feed to the hydrocracker and the resulting product were analyzed. The results refer almost exclusively to the plant-derived recycle solvent, known as the liquefaction solvent; the molecular mass range of the GC does not exceed that of the solvent. The method allows for the resolution of the numerous structural isomers of tetralin and methyl indan, one pair of hydrogen-donor (necessary for the dissolution of coal) and isomeric nondonor (that reduce the hydrogen donors) components of the recycle solvent. In addition, the n-alkanes that concentrate in the recycle solvent are easily observed in comparison with the results from one-dimensional GC-MS. 24 refs., 6 figs., 1 tab.

Jacqui F. Hamilton; Alistair. C. Lewis; Marcos Millan; Keith D. Bartle; Alan A. Herod; Rafael Kandiyoti [University of York, York (United Kingdom). Department of Chemistry

2007-01-15T23:59:59.000Z

250

Airfoil sampling of a pulsed Laval beam with tunable vacuum ultraviolet (VUV) synchrotron ionization quadrupole mass spectrometry: Application to low--temperature kinetics and product detection  

SciTech Connect (OSTI)

A new pulsed Laval nozzle apparatus with vacuum ultraviolet (VUV) synchrotron photoionization quadrupole mass spectrometry is constructed to study low-temperature radicalneutralchemical reactions of importance for modeling the atmosphere of Titan and the outer planets. A design for the sampling geometry of a pulsed Laval nozzle expansion has beendeveloped that operates successfully for the determination of rate coefficients by time-resolved mass spectrometry. The new concept employs airfoil sampling of the collimated expansion withexcellent sampling throughput. Time-resolved profiles of the high Mach number gas flow obtained by photoionization signals show that perturbation of the collimated expansion by theairfoil is negligible. The reaction of C2H with C2H2 is studied at 70 K as a proof-of-principle result for both low-temperature rate coefficient measurements and product identification basedon the photoionization spectrum of the reaction product versus VUV photon energy. This approach can be used to provide new insights into reaction mechanisms occurring at kinetic ratesclose to the collision-determined limit.

Soorkia, Satchin; Liu, Chen-Lin; Savee, John D.; Ferrell, Sarah J.; Leone, Stephen R.; Wilson, Kevin R.

2011-10-12T23:59:59.000Z

251

Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride  

E-Print Network [OSTI]

1.1 These test methods cover procedures for subsampling and for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride UF6. Most of these test methods are in routine use to determine conformance to UF6 specifications in the Enrichment and Conversion Facilities. 1.2 The analytical procedures in this document appear in the following order: Note 1—Subcommittee C26.05 will confer with C26.02 concerning the renumbered section in Test Methods C761 to determine how concerns with renumbering these sections, as analytical methods are replaced with stand-alone analytical methods, are best addressed in subsequent publications. Sections Subsampling of Uranium Hexafluoride 7 - 10 Gravimetric Determination of Uranium 11 - 19 Titrimetric Determination of Uranium 20 Preparation of High-Purity U3O 8 21 Isotopic Analysis 22 Isotopic Analysis by Double-Standard Mass-Spectrometer Method 23 - 29 Determination of Hydrocarbons, Chlorocarbons, and Partially Substitut...

American Society for Testing and Materials. Philadelphia

2011-01-01T23:59:59.000Z

252

Improving the Sensitivity of Mass Spectrometry by Using a New Sheath Flow Electrospray Emitter Array at Subambient Pressures  

Science Journals Connector (OSTI)

Arrays of chemically etched emitters with individualized sheath gas capillaries were developed to enhance electrospray ionization (ESI) efficiency at subambient pressures. By incorporating the new emitter arra...

Jonathan T. Cox; Ioan Marginean…

2014-12-01T23:59:59.000Z

253

Synchrotron Vacuum-Ultraviolet Postionization Mass Spectrometry with Laser and Ion Probes for Intact Molecular Spatial Mapping of Lignin  

E-Print Network [OSTI]

and Biosynthesis of Lignin; Springer-Verlag: Berlin, 1968. (chemical imaging studies of lignin and related compounds.and Alkali and Organosolv Lignins with Synchrotron Vacuum-UV

Takahashi, Lynelle Kazue

2011-01-01T23:59:59.000Z

254

Liquid Sampling-Atmospheric Pressure Glow Discharge (LS-APGD) Ionization Source for Elemental Mass Spectrometry: Preliminary Parametric Evaluation and Figures of Merit  

SciTech Connect (OSTI)

A new, low power ionization source for the elemental analysis of aqueous solutions has recently been described. The liquid sampling-atmospheric pressure glow discharge (LS-APGD) source operates at relatively low currents (<20 mA) and solution flow rates (<50 ?L min-1), yielding a relatively simple alternative for atomic mass spectrometry applications. The LS-APGD has been interfaced to what is otherwise an organic, LC-MS mass analyzer, the Thermo Scientific Exactive Orbitrap without any modifications; other than removing the electrospray ionization (ESI) source supplied with that instrument. A glow discharge is initiated between the surface of the test solution exiting a glass capillary and a metallic counter electrode mounted at a 90° angle and separated by a distance of ~5 mm. As with any plasma-based ionization source, there are key discharge operation and ion sampling parameters that affect the intensity and composition of the derived mass spectra; including signal-to-background ratios. We describe here a preliminary parametric evaluation of the roles of discharge current, solution flow rate, argon sheath gas flow rate, and ion sampling distance as they apply on this mass analyzer system. A cursive evaluation of potential matrix effects due to the presence of easily ionized elements (EIEs) indicate that sodium concentrations of up to 500 ?g mL-1 generally cause suppressions of less than 50%, dependant upon the analyte species. Based on the results of this series of studies, preliminary limits of detection (LOD) have been established through the generation of calibration functions. Whilst solution-based concentrations LOD levels of 0.02 – 2 ?g mL-1 3 are not impressive on the surface, the fact that they are determined via discrete 5 ?L injections leads to mass-based detection limits at picogram to singlenanogram levels. The overhead costs associated with source operation (10 W d.c. power, solution flow rates of <50 ?L min-1, and gas flow rates <10 mL min-1) are very attractive. While further optimization in the source design is suggested here, it is believed that the LS-APGD ion source may present a practical alternative to inductively-coupled plasma (ICP) sources typically employed in elemental mass spectrometry.

Quarles, C. Derrick; Carado, Anthony J.; Barinaga, Charles J.; Koppenaal, David W.; Marcus, R. Kenneth

2012-01-01T23:59:59.000Z

255

Automated probe microdistillation/mass spectrometry for the analysis of high-molecular weight compounds in fossil fuels  

SciTech Connect (OSTI)

Automated probe microdistillation/mass spectroscopy is described. The application of computer hardware and the development of computer software eliminate the dilatory nature of acquiring both the temperature and associated mass spectra and reduces the acquired data for processing. The interaction of various hardware components of the system as well as the associated software is described. (DMC)

Scheppele, S.E.; Grindstaff, Q.G.; Grigsby, R.D.; Chung, K.C.; Hwang, C.S.; Marriott, T.D.; Schronk, L.R.

1982-08-01T23:59:59.000Z

256

Thermochemical Analysis of U.S. Argonne Premium Coal Samples by Time-Resolved Pyrolysis-Field ionization Mass Spectrometry  

Science Journals Connector (OSTI)

Analytical pyrolysis techniques are widely used for the thermochemical analysis of coals and coal-derived products. During heating, complex mixtures of chemical substances are released from coal by distillatio...

Norbert Simmleit; Hans-Rolf Schulten; Yongseung Yun…

1992-01-01T23:59:59.000Z

257

Headspace gas chromatography–mass spectrometry for rapid determination of halonitromethanes in tap and swimming pool water  

Science Journals Connector (OSTI)

Halonitromethanes (HNMs) are one of the most cytotoxic and genotoxic classes found among the unregulated disinfection by-products formed by the reaction of chemical disinfectants with natural organic matter in...

I. Montesinos; M. Gallego

2012-03-01T23:59:59.000Z

258

Rapid Analysis of Lewisite Metabolites in Urine by High-Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometry  

Science Journals Connector (OSTI)

......six-week period to demonstrate the long-term previ- sion and accuracy of the...chemical weapon becomes hazardous waste. Chem. Eng. Prog. 101: 64...C. Le. Sample preparation and storage can change arsenic spe- ciation......

Rayman D. Stanelle; William J. McShane; Elena N. Dodova; R. Steven Pappas; Robert J. Kobelski

2010-04-01T23:59:59.000Z

259

C-O-H ratios of silicate melt inclusions in basalts from the Galapagos spreading center near 95 degree W: A leaser decrepitation mass spectrometry study  

SciTech Connect (OSTI)

Volatile ratios (primarily of H{sub 2}O and CO{sub 2}) in individual silicate melt (glass) inclusions in minerals have been analyzed using laser volatilization and mass spectrometry. A Nd-glass laser was used to produce 50-micrometer diameter pits in silicate melt inclusions. Released volatiles were analyzed directly with a computer-controlled quadrupole mass spectrometer. The mean CO{sub 2}/H{sub 2}O from the propagating rift (0.245 {plus minus} 0.068) silicate glass inclusions is significantly lower than that of the actively failing rift (0.641 {plus minus} 0.241); this difference probably reflects different degrees of degassing during contrasting magmatic histories for the two regions. Relatively undifferentiated failing rift magmas must have relatively short crustal residence time prior to eruption and, therefore, have not undergone significant degassing of CO{sub 2}, as would appear to be the case for the more highly fractionated propagating rift magmas. The laser-mass spectrometric system described herein has the ability to act as a point-source probing device that can differentiate between the various volatile sites in minerals and rocks (as well as synthetic materials) on a micrometer scale.

Yonover, R.N.; Sinton, J.M. (Univ. of Hawaii, Honolulu (USA)); Gibson, E.K. (NASA/Johnson Space Center, Houston, TX (USA)); Sommer, M.A.

1989-12-01T23:59:59.000Z

260

Isotope pattern deconvolution for peptide mass spectrometry by non-negative least squares/least absolute deviation template matching  

Science Journals Connector (OSTI)

Identification of overlapping isotope patterns in mass spectrometric data is achieved using non-negative least squares/non-negative least absolute deviation regression, and is able to disentangle complicated overlaps of patterns.

Martin Slawski; Rene Hussong; Andreas Tholey; Thomas Jakoby; Barbara Gregorius; Andreas Hildebrandt; Matthias Hein

2012-11-08T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Atmospheric-Pressure Argon Surface-Wave Plasma (SWP) as an Ion Source in Elemental Mass Spectrometry  

Science Journals Connector (OSTI)

Results of the study of a high-power argon surface-wave plasma as an ion source for mass spectrometric elemental analysis of aqueous solutions are presented. The plasma is operated...

Boudreau, D; Hubert, J

1993-01-01T23:59:59.000Z

262

Advanced Mass Calibration and Visualization for FT-ICR Mass Spectromet...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

for FT-ICR Mass Spectrometry Imaging. Abstract: Mass spectrometry imaging by Fourier transform ion cyclotron resonance (FT-ICR) yields hundreds of unique peaks, many of which...

263

Accurate-Mass Databases for Comprehensive Screening of Pesticide Residues in Food by Fast Liquid Chromatography Time-of-Flight Mass Spectrometry  

Science Journals Connector (OSTI)

The use of agrochemicals at various stages of cultivation has an important impact in food protection and quality preservation. ... The chromatographic method held the initial mobile phase composition (10% B) constant for 1 min, followed by a linear gradient to 100% B up to 12 min, and kept for 5 min at 100% B. The flow rate used was 0.6 mL min?1. ... Accurate-Mass Database of the Studied Pesticides Including Retention Times (RT), Theoretical Accurate Masses, and Elemental Compositions of the Detected Ions ...

Milagros Mezcua; Octavio Malato; Juan F. García-Reyes; Antonio Molina-Díaz; Amadeo R. Fernández-Alba

2008-12-31T23:59:59.000Z

264

Direct determination of the adiabatic ionization energy of NO2 as measured by guided ion-beam mass spectrometry  

E-Print Network [OSTI]

Direct determination of the adiabatic ionization energy of NO2 as measured by guided ion-beam mass the past 60 years the value for the ionization energy (IE) of nitrogen dioxide has been measured many times, Utah 84112 (Received 16 April 1992; accepted 4 May 1992) The adiabatic ionization energy (IE) of NOa

Clemmer, David E.

265

Analysis on the Go: Quantitation of Drugs of Abuse in Dried Urine with Digital Microfluidics and Miniature Mass Spectrometry  

E-Print Network [OSTI]

Analysis on the Go: Quantitation of Drugs of Abuse in Dried Urine with Digital Microfluidics the development of a method coupling microfluidics and a miniature mass spectrometer, applied to quantitation of drugs of abuse in urine. A custom digital microfluidic system was designed to deliver droplets

Zandstra, Peter W.

266

Simultaneous Determination of 16 Pyrethroid Residues in Tea Samples Using Gas Chromatography and Ion Trap Mass Spectrometry  

Science Journals Connector (OSTI)

......67-64-1 Acetone | Acetone Gas Chromatography-Mass...are widely used in tea production, and pesticide residues...Analysis was performed by gas chromatography with ion...chroma- tography (LC), gas chromatography (GC...sensitive, and low- cost detection for pyrethroids......

Kuang Hua; Miao Hong; Hou Xiaolin; Zhao Yunfeng; Wu Yongning; Xu Chuanlai

2010-10-01T23:59:59.000Z

267

Applications of High-Resolution Electrospray Ionization Mass Spectrometry to Measurements of Average Oxygen to Carbon Ratios in Secondary Organic Aerosols  

SciTech Connect (OSTI)

The applicability of high resolution electrospray ionization mass spectrometry (HR ESI-MS) to measurements of the average oxygen to carbon ratio (O/C) in organic aerosols was investigated. Solutions with known average O/C containing up to 10 standard compounds representative of secondary organic aerosol (SOA) were analyzed and corresponding electrospray ionization efficiencies were quantified. The assumption of equal ionization efficiency commonly used in estimating O/C ratios of organic aerosols was found to be reasonably accurate. We found that the accuracy of the measured O/C ratios increases by averaging the values obtained from both (+) and (-) modes. A correlation was found between the ratio of the ionization efficiencies in the positive and negative ESI modes with the octanol-water partition constant, and more importantly, with the compound's O/C. To demonstrate the utility of this correlation for estimating average O/C values of unknown mixtures, we analyzed the ESI (+) and ESI (-) data for SOA produced by oxidation of limonene and isoprene and compared to online O/C measurements using an aerosol mass spectrometer (AMS). This work demonstrates that the accuracy of the HR ESI-MS methods is comparable to that of the AMS, with the added benefit of molecular identification of the aerosol constituents.

Bateman, Adam P.; Laskin, Julia; Laskin, Alexander; Nizkorodov, Sergey

2012-07-02T23:59:59.000Z

268

Standard test method for analysis of urine for uranium-235 and uranium-238 isotopes by inductively coupled plasma-mass spectrometry  

E-Print Network [OSTI]

1.1 This test method covers the determination of the concentration of uranium-235 and uranium-238 in urine using Inductively Coupled Plasma-Mass Spectrometry. This test method can be used to support uranium facility bioassay programs. 1.2 This method detection limits for 235U and 238U are 6 ng/L. To meet the requirements of ANSI N13.30, the minimum detectable activity (MDA) of each radionuclide measured must be at least 0.1 pCi/L (0.0037 Bq/L). The MDA translates to 47 ng/L for 235U and 300 ng/L for 238U. Uranium– 234 cannot be determined at the MDA with this test method because of its low mass concentration level equivalent to 0.1 pCi/L. 1.3 The digestion and anion separation of urine may not be necessary when uranium concentrations of more than 100 ng/L are present. 1.4 Units—The values stated in picoCurie per liter units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1....

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

269

An Ultra-Trace Analysis Technique for SF6 Using Gas Chromatography with Negative Ion Chemical Ionization Mass Spectrometry  

Science Journals Connector (OSTI)

......Mark H.L. A preliminary evaluation of gas air tracers. Journal of the Air Pollution Control Association (1965) 15(3):109-112...hygiene investigations. In: 12th AIVC Conference - Air Movement and Ventilation Control Within Buildings......

Edmund C. Jong; Paul V. Macek; Inoka E. Perera; Kray D. Luxbacher; Harold M. McNair

270

New approaches for the chemical and physical characterization of aerosols using a single particle mass spectrometry based technique  

E-Print Network [OSTI]

composition of fly ash from a coal-fired thermal powersignature for coal combustion or fly ash particles. Singleresembles fly ash particles formed by coal combustion (

Spencer, Matthew Todd

2007-01-01T23:59:59.000Z

271

Mass Spectrometer: Orbitrap | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Software (ISIS): A Machine Learning Approach to Tandem Mass Spectral Identification of Lipids. Liquid chromatography-mass spectrometry-based metabolomics has gained importance...

272

CHEMICAL EVOLUTION IN HIGH-MASS STAR-FORMING REGIONS: RESULTS FROM THE MALT90 SURVEY  

SciTech Connect (OSTI)

The chemical changes of high-mass star-forming regions provide a potential method for classifying their evolutionary stages and, ultimately, ages. In this study, we search for correlations between molecular abundances and the evolutionary stages of dense molecular clumps associated with high-mass star formation. We use the molecular line maps from Year 1 of the Millimetre Astronomy Legacy Team 90 GHz (MALT90) Survey. The survey mapped several hundred individual star-forming clumps chosen from the ATLASGAL survey to span the complete range of evolution, from prestellar to protostellar to H II regions. The evolutionary stage of each clump is classified using the Spitzer GLIMPSE/MIPSGAL mid-IR surveys. Where possible, we determine the dust temperatures and H{sub 2} column densities for each clump from Herschel/Hi-GAL continuum data. From MALT90 data, we measure the integrated intensities of the N{sub 2}H{sup +}, HCO{sup +}, HCN and HNC (1-0) lines, and derive the column densities and abundances of N{sub 2}H{sup +} and HCO{sup +}. The Herschel dust temperatures increase as a function of the IR-based Spitzer evolutionary classification scheme, with the youngest clumps being the coldest, which gives confidence that this classification method provides a reliable way to assign evolutionary stages to clumps. Both N{sub 2}H{sup +} and HCO{sup +} abundances increase as a function of evolutionary stage, whereas the N{sub 2}H{sup +} (1-0) to HCO{sup +} (1-0) integrated intensity ratios show no discernable trend. The HCN (1-0) to HNC(1-0) integrated intensity ratios show marginal evidence of an increase as the clumps evolve.

Hoq, Sadia; Jackson, James M.; Foster, Jonathan B.; Sanhueza, Patricio; Claysmith, Christopher [Institute for Astrophysical Research, Boston University, Boston, MA 02215 (United States); Guzmán, Andrés [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Whitaker, J. Scott [Physics Department, Boston University, Boston, MA 02215 (United States); Rathborne, Jill M. [Australia Telescope National Facility, CSIRO Astronomy and Space Science, Epping, NSW (Australia); Vasyunina, Tatiana; Vasyunin, Anton, E-mail: shoq@bu.edu, E-mail: jackson@bu.edu, E-mail: patricio@bu.edu, E-mail: claysmit@bu.edu, E-mail: jonathan.b.foster@yale.edu, E-mail: aguzmanf@cfa.harvard.edu, E-mail: scott@bu.edu, E-mail: rathborne@csiro.au, E-mail: tv3h@virginia.edu, E-mail: aiv3f@virginia.edu [Department of Chemistry, University of Virginia, Charlottesville, VA 22904 (United States)

2013-11-10T23:59:59.000Z

273

Mass, energy, and exergy balance analysis of chemical looping with oxygen uncoupling (CLOU) process  

Science Journals Connector (OSTI)

Abstract Chemical looping with oxygen uncoupling (CLOU) is a promising concept for efficient combustion of solid fuels with an inherent capture of the greenhouse gas CO 2 . This paper presents a CLOU process scheme with stoichiometric mass, energy, and exergy balances. A CLOU reactor system using medium volatile bituminous coal as fuel and silica-supported CuO as an oxygen carrier is analyzed. The analysis includes the estimation of various design and operational parameters, thermal considerations, and evaluation of the overall performance. The operation of a reactor system of two interacting circulating fluidized beds (CFBs) is greatly influenced by the hydrodynamics. For the CuO oxygen carrier, the hydrodynamic operating range appeared feasible considering the maximum solid circulation rates in current CFB boilers. Depending upon the reactor temperatures, oxygen carrier inventories of 400–680 kg/MW in the system were found necessary for stoichiometric combustion of the fuel. The temperature difference between the reactors should not exceed 50 °C, as otherwise, problems may arise with the heat balance. Exergetic efficiencies in the range of 63–70% were obtained for different combinations of relevant design parameters. It is evident that the possible operating conditions in the system are closely related to the properties of the chosen oxygen carrier. However, the calculation procedure and design criteria presented here are applicable to any oxygen carrier to be used in the process.

Petteri Peltola; Tero Tynjälä; Jouni Ritvanen; Timo Hyppänen

2014-01-01T23:59:59.000Z

274

Rapid characterization of lignocellulosic feedstocks for fuels and chemicals: Molecular beam mass spectrometric approach  

SciTech Connect (OSTI)

Rapid characterization of biomass feedstocks has a pivotal role in the development of biomass energy because of the large number of samples that must be analyzed due to the diversity of biomass feedstocks and the significant differences in the chemical and physical properties of these feedstocks. Several biomass feedstocks (herbaceous, woody, and agricultural residues) were screened for the effects of storage, season of harvest, geographic location, clonal, and species variation on the pyrolysis products of the feed stocks. For herbaceous species such as sericea lespedeza, the season of harvest had a significant effect on the pyrolysis products. Effects of clonal variation on the composition of hybrid poplar feedstocks was easily discerned with the molecular beam mass spectrometric analysis. The effect of geographic location on the poplar clones pyrolysis products was minimal. However in the case of switchgrass, varietal influence on the pyrolysis products was minimal, but where the plant was grown had a strong influence on the pyrolysis products of the feedstock. Significant differences because of species variation could also be shown from the pyrolysis products of various biomass feedstocks. The influence of storage time on biomass samples stored outside in the open could also be discerned from the pyrolysis products of the feedstocks. The differences noted in the pyrolysis products of the feedstocks were noted for samples which were significantly degraded during storage either through the action of microflora or weathering.

Agblevor, F.A.; Davis, M.F. [National Renewable Energy Lab., Golden, CO (United States)

1996-12-31T23:59:59.000Z

275

Confirmatory analysis of ethylglucuronide in urine by liquid-chromatography/electrospray ionization/tandem mass spectrometry according to forensic guidelines  

Science Journals Connector (OSTI)

?-D-ethylglucuronide (EtG) is a stable Phase II metabolite of ethanol which can be detected in urine samples several days after elimination of ethanol. It is a useful diagnostic parameter for monitoring abstinence of alcoholics in alcohol withdrawal treatment. For this purpose, determination in urine is mainly performed by LC-MS, LC-MS/MS, or by GC-MS. For the mass spectrometric identification and detection of controlled substances in more sensitive fields such as forensic toxicology, workplace drug testing, doping analysis, and veterinary organic residue control, official guidelines have been released requiring a chromatographic separation and a minimum of two mass spectrometric transitions of the analyte. However, for detection of EtG none of the published LC-MS/MS methods could fulfill the minimum requirements of any of these guidelines. Therefore, an existing LC-MS/MS method has been modified by monitoring further MS/MS transitions instead of only one (deprotonated molecule [M ? H]?/product ions: m/z 75, 85, 113, and 159 optional) with the aim of withstanding administrative or court scrutiny in forensic or workplace drug testing cases. Full method validation has been performed in accordance to guidelines of the German Society of Toxicology and Forensic Chemistry (GTFCh) and requirements of ISO 17025. One application field in the United States is a workplace monitoring program to detect surreptitious alcohol use among recovering health professionals, who by contract had agreed on total abstinence after drug and alcohol withdrawal therapy.

Wolfgang Weinmann; Patrick Schaefer; Annette Thierauf; André Schreiber; Friedrich Martin Wurst

2004-01-01T23:59:59.000Z

276

Radio-frequency glow discharge spectrometry:: A critical review  

Science Journals Connector (OSTI)

This paper presents a critical review of analytical radio frequency glow discharge spectrometry (rf-GDS). The historical foundations of rf-GDS are described, and current knowledge of the fundamental physics of analytical rf glow discharges is discussed. Additionally, instrumentation, methodologies, and applications of rf glow discharge optical emission spectrometry (rf-GDOES) and mass spectrometry (rf-GDMS) are reviewed. Although other rf-GDS techniques have appeared [e.g. rf glow discharge atomic absorption spectrophotometry (rf-GDAAS)], the emphasis is placed upon rf-GDOES and rf-GDMS, because they have received by far the most interest from analytical chemical metrologists. This review also provides explanations of some developments that are needed for further progress in the field of analytical rf-GDS.

Michael R. Winchester; Richard Payling

2004-01-01T23:59:59.000Z

277

Soluble arsenic and selenium species in fly ash/organic waste-amended soils using ion chromatography-inductively coupled plasma mass spectrometry  

SciTech Connect (OSTI)

Mixing coal fly ash with an organic waste increases macronutrient content and may make land application of fly ash a viable disposal alternative. However, trace element chemistry of these mixed waste products warrants investigation. Speciation of As and Se in soil solutions of fly ash-, poultry litter- and sewage sludge-amended soils was determined over a 10-day period by ion chromatography coupled to inductively coupled plasma mass spectrometry (IC-ICP-MS). Detection limits were 0.031, 0.028, 0.051, 0.161, 0.497, and 0.660 {micro}g L{sup {minus}1} for dimethylarsinate (DMA), As(III), monomethylarsonate (MMA), As(V), Se(IV), and Se(VI), respectively. Arsenic was highly water-soluble from poultry litter and appeared to be predominantly As(V). Arsenic(V) was the predominant species in soil amended with two fly ashes. Application of fly ash/poultry litter mixtures increased As solubility and led to the prevalence of DMA as the major As species. DMA concentrations of these soil solutions decreased rapidly over the sampling period relative to As(V), suggesting that DMA readily underwent mineralization in the soil solution. Se(VI) was the predominant soluble Se species in all treatments indicating rapid oxidation of Se(IV) initially solubilized from the fly ashes.

Jackson, B.P.; Miller, W.P. [Univ. of Georgia, Athens, GA (United States). Dept. of Crop and Soil Sciences] [Univ. of Georgia, Athens, GA (United States). Dept. of Crop and Soil Sciences

1999-01-15T23:59:59.000Z

278

Rapid determination of endogenous cytokinins in plant samples by combination of magnetic solid phase extraction with hydrophilic interaction chromatography–tandem mass spectrometry  

Science Journals Connector (OSTI)

A 2-acrylamido-2-methyl-1-propanesulfonic acid-co-ethylene glycol dimethacrylate (Fe3O4/SiO2/P(AMPS-co-EGDMA)) copolymer was prepared and used as a magnetic solid phase extraction (MSPE) medium for recovery of endogenous cytokinins (CKs) from plant extracts. This magnetic porous polymer was characterized by electron microscopy, nitrogen sorption experiments, elemental analysis and Fourier-transformed infrared spectroscopy. It was demonstrated to have high extraction capacity toward \\{CKs\\} in plants due to its specificity, surface area and porous structure. Coupled with hydrophilic interaction chromatography–tandem mass spectrometry (HILIC–MS/MS), a rapid, simple, and effective MSPE–HILIC–MS/MS analytical method for the quantitative analysis of endogenous \\{CKs\\} in Oryza sativa (O. sativa) roots was successfully established. Good linearities were obtained for all \\{CKs\\} investigated with correlation coefficients (R2) > 0.9975. The results showed that \\{LODs\\} (S/N = 3) were ranged from 0.18 to 3.65 pg mL?1. Reproducibility of the method was obtained with intra-day and inter-day relative standard deviations (RSDs) less than 16.1% and the recoveries in plant samples ranged from 72.8% to 115.5%. Finally, the MSPE–HILIC–MS/MS method was applied to several plant samples, and the amounts of endogenous \\{CKs\\} in O. sativa roots, leaves and Arabidopsis thaliana (A. thaliana) were successfully determined.

Zhao Liu; Bao-Dong Cai; Yu-Qi Feng

2012-01-01T23:59:59.000Z

279

Determination of N,N-dimethyltryptamine in beverages consumed in religious practices by headspace solid-phase microextraction followed by gas chromatography ion trap mass spectrometry  

Science Journals Connector (OSTI)

A novel analytical approach combining solid-phase microextraction (SPME)/gas chromatography ion trap mass spectrometry (GC-IT-MS) was developed for the detection and quantification N,N-dimethyltryptamine (DMT), a powerful psychoactive indole alkaloid present in a variety of South American indigenous beverages, such as ayahuasca and vinho da jurema. These particular plant products, often used within a religious context, are increasingly consumed throughout the world following an expansion of religious groups and the availability of plant material over the Internet and high street shops. The method described in the present study included the use of SPME in headspace mode combined GC-IT-MS and included the optimization of the SPME procedure using multivariate techniques. The method was performed with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber in headspace mode (70 min at 60 °C) which resulted in good precision (RSD9975) was also observed. In addition, the proposed method showed good robustness and allowed for the minimization of sample manipulation. Five jurema beverage samples were prepared in the laboratory in order to study the impact of temperature, pH and ethanol on the ability to extract DMT into solution. The developed method was then applied to the analysis of twelve real ayahuasca and vinho da jurema samples, obtained from Brazilian religious groups, which revealed DMT concentration levels between 0.10 and 1.81 g L?1.

Alain Gaujac; Nicola Dempster; Sandro Navickiene; Simon D. Brandt; Jailson Bittencourt de Andrade

2013-01-01T23:59:59.000Z

280

Determination of actinides in environmental and biological samples using high-performance chelation ion chromatography coupled to sector-field inductively coupled plasma mass spectrometry  

Science Journals Connector (OSTI)

High-performance chelation ion chromatography, using a neutral polystyrene substrate dynamically loaded with 0.1 mM dipicolinic acid, coupled with sector-field inductively coupled plasma mass spectrometry has been successfully used for the separation of the actinides thorium, uranium, americium, neptunium and plutonium. Using this column it was possible to separate the various actinides from each other and from a complex sample matrix. In particular, it was possible to separate plutonium and uranium to facilitate the detection of the former free of spectral interference. The column also exhibited some selectivity for different oxidation states of Np, Pu and U. Two oxidation states each for plutonium and neptunium were found, tentatively identified as Np(V) and Pu(III) eluting at the solvent front, and Np(IV) and Pu(IV) eluting much later. Detection limits were 12, 8, and 4 fg for 237Np, 239Pu, and 241Am, respectively, for a 0.5 ml injection. The system was successfully used for the determination of 239Pu in NIST 4251 Human Lung and 4353 Rocky Flats Soil, with results of 570±29 and 2939±226 fg g?1, respectively, compared with a certified range of 227–951 fg g?1 for the former and a value of 3307± 248 fg g?1 for the latter.

Jason B. Truscott; Phil Jones; Ben E. Fairman; E. Hywel Evans

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Chemometric optimization of dispersive suspended microextraction followed by gas chromatography–mass spectrometry for the determination of polycyclic aromatic hydrocarbons in natural waters  

Science Journals Connector (OSTI)

Abstract A dispersive suspended microextraction (DSME) method coupled with gas chromatography–mass spectrometry (GC–MS) was developed and validated for the simultaneous determination of ten polycyclic aromatic hydrocarbons in real water samples. The optimization of the method was achieved with a 27–4 Plackett–Burman design, while the significant factors were optimized using a central composite design (CCD). The parameters that were studied included the sample volume, organic solvent volume, extraction time, restoration time and organic solvent. The optimum experimental conditions for the proposed method comprised 4.3 mL of the water sample, 93 ?L of toluene as the extraction solvent, a 104-s extraction time and a 10-min restoration time. The recoveries varied from 70 to 111%. Chrysene was the least recovered compound, while anthracene displayed the highest extraction efficiency. The analytical method (DSME) was shown to be linear (R2 > 0.993) over the studied range of concentrations, exhibiting satisfactory precision (RSD% < 10.6%) and reaching limits of detection between 8 and 46 ng L?1.

Nikolaos P. Petridis; Vasilios A. Sakkas; Triantafyllos A. Albanis

2014-01-01T23:59:59.000Z

282

Chemical Analysis of Complex Organic Mixtures Using Reactive...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Mass Spectrometry. Abstract: Reactive nanospray desorption electrospray ionization (nano-DESI) combined with high-resolution mass spectrometry was utilized for the analysis of...

283

Slurry Nebulization-Inductively Coupled Plasma Mass Spectrometry with Solution Calibration for Determination of Ultratrace Boron in High Pure Nuclear Graphite Powder  

Science Journals Connector (OSTI)

Slurry nebulization-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the direct determination of trace boron (B) in high-purity graphite powders. After the graphite powders were ground and sifted, the particle size of graphite was collected less than 5 ?m. Polyvinylpyrrolidone (PVP) was used as the dispersant in slurry preparation. The optimal mass ratio of PVP to the graphite was found to be 0.5. Well-proportioned and stable slurry solution was obtained by magnetic stirrer. 0.1 M NH4OH as the aqueous medium could provide the optimal pH of 10 for the stable slurry and eliminate the memory effect of B. ICP-MS was operated in a higher resolution mode (0.6 amu) to eliminate the interference with the matrix 12C by peak tailing. Oxygen was added into the plasma at a flow rate of 60 mL min?1 to resolve carbon deposition on the sampler and skimmer cones and accelerate particle dissociation in the plasma. External calibration with aqueous solution standards was established for quantification. Beryllium was chosen as the internal standard to evaluate the efficiency of matrix effect correction. A correlation coefficient of 0.9995 was obtained for B concentration ranging 2–200 ?g L?1. The detection limit (3S) of B was 0.095 ?g g?1. As a practical application, the proposed method was used for the determination of trace B in four nuclear graphite samples (claimed 99.999% purity), with the satisfactory recoveries for the spike tests in the range of 97.2%–103.1%.

Xin-Li LIU; Tai-Cheng DUAN; Yi HAN; Xiao-Yu JIA; Wei-Na ZHANG; Hang-Ting CHEN

2010-01-01T23:59:59.000Z

284

C60 Secondary Ion Fourier Transform Ion Cyclotron Resonance Mass...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

C60 Secondary Ion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. C60 Secondary Ion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Abstract: Secondary...

285

A Hybrid Approach to Protein Differential Expression in Mass...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Hybrid Approach to Protein Differential Expression in Mass Spectrometry-Based Proteomics. A Hybrid Approach to Protein Differential Expression in Mass Spectrometry-Based...

286

Atmospheric Amines and Ammonia Measured with a Chemical Ionization Mass Spectrometer (CIMS)  

SciTech Connect (OSTI)

We report ambient measurements of amines and ammonia with a fast response chemical ionization mass spectrometer (CIMS) in a Southeastern U.S. forest in Alabama and a moderately polluted Midwestern site during the summer. In the Alabama forest, mostly C3-amines (from pptv to tens of pptv) and ammonia (up to 2 ppbv) were detected on a daily basis. C3-amines and ammonia showed similar diurnal trends and temperature and wind direction dependences, and were not associated with transported CO and SO2 plumes. Consistent with temperature dependences, amine and ammonia in the gas and aerosol phases showed opposite diurnal trends, indicating gas-to-particle partitioning of amines and ammonia. Temperature dependences also imply reversible processes of amines and ammonia evaporation from soil surfaces in daytime and deposition of amines and ammonia to soil surfaces at nighttime. Various amines (C1-C6) at the pptv level were observed in the transported biomass burning plumes, showing that biomass burning can be a substantial source of amines in the Southeast U.S. At the moderately polluted Kent site, higher concentrations of amines (C1-C6, from pptv to tens of pptv) and ammonia (up to 6 ppbv) were detected. Diurnal variations of C1- to C3-amines and ammonia were correlated with the ambient temperature. C4- to C6-amines showed abrupt increases during the nighttime, suggesting that they were emitted from local sources. These abundant amines and ammonia may in part explain the frequent new particle formation events reported from Kent. Lower amine concentrations at the rural forested site highlight the importance of constraining anthropogenic sources of amines.

You, Y.; Kanawade, V. P.; de Gouw, J. A.; Guenther, Alex B.; Madronich, Sasha; Sierra-Hernandez, M. R.; Lawler, M.; Smith, James N.; Takahama, S.; Ruggeri, G.; Koss, A.; Olson, K.; Baumann, K.; Weber, R. J.; Nenes, A.; Guo, H.; Edgerton, Eric S.; Porcelli, L.; Brune, W. H.; Goldstein, Allen H.; Lee, S.-H

2014-11-19T23:59:59.000Z

287

E-Print Network 3.0 - absorption spectrometry feasibility Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Franc&o, CA 94101&fM, USA Laser Microprobe Mass Spectrometry Summary: graphite fur- nace atomic absorption spectrometry (ETAAS) measurement of tin in sulfate matrices were......

288

Targeted Peptide Measurements in Biology and Medicine: Best Practices for Mass Spectrometry-based Assay Development Using a Fit-for-Purpose Approach  

SciTech Connect (OSTI)

Adoption of targeted mass spectrometry (MS) approaches such as multiple reaction monitoring (MRM) to study biological and biomedical questions is well underway in the proteomics community. Successful application depends on the ability to generate reliable assays that uniquely and confidently identify target peptides in a sample. Unfortunately, there is a wide range of criteria being applied to say that an assay has been successfully developed. There is no consensus on what criteria are acceptable and little understanding of the impact of variable criteria on the quality of the results generated. Publications describing targeted MS assays for peptides frequently do not contain sufficient information for readers to establish confidence that the tests work as intended or to be able to apply the tests described in their own labs. Guidance must be developed so that targeted MS assays with established performance can be made widely distributed and applied by many labs worldwide. To begin to address the problems and their solutions, a workshop was held at the National Institutes of Health with representatives from the multiple communities developing and employing targeted MS assays. Participants discussed the analytical goals of their experiments and the experimental evidence needed to establish that the assays they develop work as intended and are achieving the required levels of performance. Using this “fit-for-purpose” approach, the group defined three tiers of assays distinguished by their performance and extent of analytical characterization. Computational and statistical tools useful for the analysis of targeted MS results were described. Participants also detailed the information that authors need to provide in their manuscripts to enable reviewers and readers to clearly understand what procedures were performed and to evaluate the reliability of the peptide or protein quantification measurements reported. This paper presents a summary of the meeting and recommendations. Molecular & Cellular Proteomics 13: 10.1074/mcp.M113.036095, 907–917, 2014.

Carr, Steven A.; Abbateillo, Susan E.; Ackermann, Bradley L.; Borchers, Christoph H.; Domon, Bruno; Deutsch, Eric W.; Grant, Russel; Hoofnagle, Andrew N.; Huttenhain, Ruth; Koomen, John M.; Liebler, Daniel; Liu, Tao; MacLean, Brendan; Mani, DR; Mansfield, Elizabeth; Neubert, Hendrik; Paulovich, Amanda G.; Reiter, Lukas; Vitek, Olga; Aebersold, Ruedi; Anderson, Leigh N.; Bethem, Robert; Blonder, Josip; Boja, Emily; Botelho, Julianne; Boyne, Michael; Bradshaw, Ralph A.; Burlingame, Alma S.; Chan, Daniel W.; Keshishian, Hasmik; Kuhn, Eric; Kingsinger, Christopher R.; Lee, Jerry S.; Lee, Sang-Won; Moritz, Robert L.; Oses-Prieto, Juan; Rifai, Nader; Ritchie, James E.; Rodriguez, Henry; Srinivas, Pothur R.; Townsend, Reid; Van Eyk , Jennifer; Whiteley, Gordon; Wiita, Arun; Weintraub, Susan

2014-01-14T23:59:59.000Z

289

Rapid Quantitation of Ascorbic and Folic Acids in SRM 3280 Multivitamin/Multielement Tablets using Flow-Injection Tandem Mass Spectrometry  

SciTech Connect (OSTI)

RATIONALE: Ascorbic acid (AA) and folic acid (FA) are water-soluble vitamins and are usually fortified in food and dietary supplements. For the safety of human health, proper intake of these vitamins is recommended. Improvement in the analysis time required for the quantitative determination of these vitamins in food and nutritional formulations is desired. METHODS: A simple and fast (~5 min) in-tube sample preparation was performed, independently for FA and AA, by mixing extraction solvent with a powdered sample aliquot followed by agitation, centrifugation, and filtration to recover an extract for analysis. Quantitative detection was achieved by flow-injection (1 L injection volume) electrospray ionization tandem mass spectrometry (ESI-MS/MS) in negative ion mode using the method of standard addition. RESULTS: Method of standard addition was employed for the quantitative estimation of each vitamin in a sample extract. At least 2 spiked and 1 non-spiked sample extract were injected in triplicate for each quantitative analysis. Given an injection-to-injection interval of approximately 2 min, about 18 min was required to complete the quantitative estimation of each vitamin. The concentration values obtained for the respective vitamins in the standard reference material (SRM) 3280 using this approach were within the statistical range of the certified values provided in the NIST Certificate of Analysis. The estimated limit of detections of FA and AA were 13 and 5.9 ng/g, respectively. CONCLUSIONS: Flow-injection ESI-MS/MS was successfully applied for the rapid quantitation of FA and AA in SRM 3280 multivitamin/multielement tablets.

Bhandari, Deepak [ORNL] [ORNL; Kertesz, Vilmos [ORNL] [ORNL; Van Berkel, Gary J [ORNL] [ORNL

2013-01-01T23:59:59.000Z

290

Development of Ion Mobility-mass Spectrometry Instrumentation to Probe the Conformations and Capture the Solution to Gas Phase Transition of Electrosprayed Biomolecules  

E-Print Network [OSTI]

(i.e., peptides and proteins) produced upon ESI and provide new insight into their solution to gas phase evolution. First, fundamental principles of periodic focusing ion mobility spectrometry are comprehensively discussed. Radial ion confinement...

Silveira, Joshua A

2013-11-22T23:59:59.000Z

291

High-Throughput Identification of Bacteria and Yeast by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry in Conventional Medical Microbiology Laboratories  

Science Journals Connector (OSTI)

...D. J., T. R. Olma, and G. L. Gilbert. 1998. Evaluation of four methods...spectrometry in conventional medical microbiology laboratories. | Matrix-assisted laser...laboratory. | Department of Medical Microbiology, Leiden University Medical Center...

S. Q. van Veen; E. C. J. Claas; Ed J. Kuijper

2010-01-06T23:59:59.000Z

292

Determination of Mercury in Soils by Flameless Atomic Absorption Spectrometry  

Science Journals Connector (OSTI)

...chemical analysis exploration flameless geochemical methods mercury...Determination of Mercury in Soils by Flameless Atomic Absorption Spectrometry...Determinationof Mercury in Soilsby Flameless Atomic AbsorptionSpectrometry...the mercuryre- RF Induction Heater work coils 1. Carriergas...

B. G. Weissberg

293

Interfacing Chromatography and Mass Spectrometry  

Science Journals Connector (OSTI)

......an active area of 1 to 2...of a known thermal sensitivity...interfacing is the large unbalance...pressure, an atmospheric pressure...to the ion plasma by a stream...occur in the atmospheric pres- sure...in the ion plasma and compete...doubtful that non-volatile...seldom a large number...work in this area using a variety...operated with RF only. The......

William H. McFadden

1979-01-01T23:59:59.000Z

294

Neutralization of chemical and biological weapons of mass destruction using nuclear methods  

E-Print Network [OSTI]

Nuclear Science Center Reactor. M. S. Thesis. Texas A&M University. August 2001. Kruger, H. and Mcndelsohn, E. Neutralization of Chemical/Biological Ballistic Warheads by Low- Yield Nuclear Interceptors. Lawrence Livermorc National Laboratory; (UCRL...-ID-111403); August 1992. Mendelsohn, E. Neutron Shielding of Chemical/Biological Warheads to Minimize the Effects from Low-yield Nuclear Interceptors. Lawrence Livermore National Laboratory; (UCRL-ID-112014); October 1992. Mendelsohn, E. Effectiveness...

McAffrey, Veronica Lynn

2012-06-07T23:59:59.000Z

295

E-Print Network 3.0 - alpha spectrometry contribution Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Tissue Composition using Peak Intensity... Kortrijk, E. Sabbelaan 53, B-8500 Kortrijk, Belgium. Abstract-- Imaging mass spectrometry or mass spectral... dimension to mass...

296

Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions  

E-Print Network [OSTI]

1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Plutonium by Controlled-Potential Coulometry Plutonium by Amperometric Titration with Iron(II) Plutonium by Diode Array Spectrophotometry Free Acid by Titration in an Oxalate Solution 8 to 15 Free Acid by Iodate Precipitation-Potentiometric Titration Test Method 16 to 22 Uranium by Arsenazo I Spectrophotometric Test Method 23 to 33 Thorium by Thorin Spectrophotometric Test Method 34 to 42 Iron by 1,10-Phenanthroline Spectrophotometric Test Method 43 to 50 Impurities by ICP-AES Chloride by Thiocyanate Spectrophotometric Test Method 51 to 58 Fluoride by Distillation-Spectrophotometric Test Method 59 to 66 Sulfate by Barium Sulfate Turbidimetric Test Method 67 to 74 Isotopic Composition by Mass Spectrom...

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

297

MetPP: a computational platform for comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry-based metabolomics  

Science Journals Connector (OSTI)

......herein report a computational platform for analysis of metabolomics...v = 4:1). Details of chemicals, sample preparation (spike-in...second dimension time (s), chemical abstract system (CAS) number...CONCLUSIONS A computational platform for analysis of metabolomics......

Xiaoli Wei; Xue Shi; Imhoi Koo; Seongho Kim; Robin H. Schmidt; Gavin E. Arteel; Walter H. Watson; Craig McClain; Xiang Zhang

2013-07-15T23:59:59.000Z

298

Magnetic fields and chemical peculiarities of the very young intermediate-mass binary system HD 72106  

E-Print Network [OSTI]

The recently discovered magnetic Herbig Ae and Be stars may provide qualitatively new information about the formation and evolution of magnetic Ap and Bp stars. We have performed a detailed investigation of one particularly interesting binary system with a Herbig Ae secondary and a late B-type primary possessing a strong, globally ordered magnetic field. Twenty high-resolution Stokes V spectra of the system were obtained with the ESPaDOnS instrument mounted on the CFHT. In these observations we see clear evidence for a magnetic field in the primary, but no evidence for a magnetic field in the secondary. A detailed abundance analysis was performed for both stars, revealing strong chemical peculiarities in the primary and normal chemical abundances in the secondary. The primary is strongly overabundant in Si, Cr, and other iron-peak elements, as well as Nd, and underabundant in He. The primary therefore appears to be a very young Bp star. In this context, line profile variations of the primary suggest non-unifo...

Folsom, C P; Kochukhov, O; Alecian, E; Catala, C; Bagnulo, S; Böhm, T; Bouret, J -C; Donati, J -F; Grunhut, J; Hanes, D A; Landstreet, J D

2008-01-01T23:59:59.000Z

299

Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solutions  

E-Print Network [OSTI]

1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solution to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Determination of Uranium 7 Specific Gravity by Pycnometry 15-20 Free Acid by Oxalate Complexation 21-27 Determination of Thorium 28 Determination of Chromium 29 Determination of Molybdenum 30 Halogens Separation by Steam Distillation 31-35 Fluoride by Specific Ion Electrode 36-42 Halogen Distillate Analysis: Chloride, Bromide, and Iodide by Amperometric Microtitrimetry 43 Determination of Chloride and Bromide 44 Determination of Sulfur by X-Ray Fluorescence 45 Sulfate Sulfur by (Photometric) Turbidimetry 46 Phosphorus by the Molybdenum Blue (Photometric) Method 54-61 Silicon by the Molybdenum Blue (Photometric) Method 62-69 Carbon by Persulfate Oxidation-Acid Titrimetry 70 Conversion to U3O8 71-74 Boron by ...

American Society for Testing and Materials. Philadelphia

1999-01-01T23:59:59.000Z

300

THERMOHALINE MIXING: DOES IT REALLY GOVERN THE ATMOSPHERIC CHEMICAL COMPOSITION OF LOW-MASS RED GIANTS?  

SciTech Connect (OSTI)

First results of our three-dimensional numerical simulations of thermohaline convection driven by {sup 3}He burning in a low-mass red giant branch (RGB) star at the bump luminosity are presented. They confirm our previous conclusion that this convection has a mixing rate that is a factor of 50 lower than the observationally constrained rate of RGB extra-mixing. It is also shown that the large-scale instabilities of the salt-fingering mean field (those of the Boussinesq and advection-diffusion equations averaged over length and timescales of many salt fingers), which have been observed to increase the rate of oceanic thermohaline mixing up to one order of magnitude, do not enhance the RGB thermohaline mixing. We speculate on possible alternative solutions of the problem of RGB extra-mixing, among which the most promising one that is related to thermohaline mixing takes advantage of the shifting of the salt-finger spectrum toward larger diameters by toroidal magnetic field.

Denissenkov, Pavel A. [Department of Physics and Astronomy, University of Victoria, P.O. Box 3055, Victoria, BC, V8W 3P6 (Canada); Merryfield, William J., E-mail: pavel.denisenkov@gmail.com, E-mail: bill.merryfield@ec.gc.ca [Canadian Centre for Climate Modelling and Analysis, University of Victoria, P.O. Box 3065, Victoria, BC, V8W 3V6 (Canada)

2011-01-20T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Device for collecting chemical compounds and related methods  

DOE Patents [OSTI]

A device for sampling chemical compounds from fixed surfaces and related methods are disclosed. The device may include a vacuum source, a chamber and a sorbent material. The device may utilize vacuum extraction to volatilize the chemical compounds from the fixed surfaces so that they may be sorbed by the sorbent material. The sorbent material may then be analyzed using conventional thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) instrumentation to determine presence of the chemical compounds. The methods may include detecting release and presence of one or more chemical compounds and determining the efficacy of decontamination. The device may be useful in collection and analysis of a variety of chemical compounds, such as residual chemical warfare agents, chemical attribution signatures and toxic industrial chemicals.

Scott, Jill R.; Groenewold, Gary S.; Rae, Catherine

2013-01-01T23:59:59.000Z

302

A Rapid, Sensitive Method for the Quantitation of Specific Metabolites of Sulfur Mustard in Human Urine Using Isotope-Dilution Gas Chromatography-Tandem Mass Spectrometry  

Science Journals Connector (OSTI)

......Chemicals, remains a public health concern because it is simple...synthetic methods make HD a dangerous chemical warfare agent. In...tinued monitoringfor long-term health effects)from the wor- ried...the initial stages ofa public health re- sponse because additional......

Carrie L. Young; Doris Ash; W. Jack Driskell; Anne E. Boyer; Rodolfo A. Martinez; L.A. Silks; John R. Barr

2004-01-01T23:59:59.000Z

303

Current developments in laser ablation-inductively coupled plasma-mass spectrometry for use in geology, forensics, and nuclear nonproliferation research  

SciTech Connect (OSTI)

This dissertation focused on new applications of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The diverse fields that were investigated show the versatility of the technique. In Chapter 2, LA-ICP-MS was used to investigate the rare earth element (REE) profiles of garnets from the Broken Hill Deposit in New South Wales, Australia. The normalized REE profiles helped to shed new light on the formation of deposits of sulfide ores. This information may be helpful in identifying the location of sulfide ore deposits in other locations. New sources of metals such as Pg, Zn, and Ag, produced from these ores, are needed to sustain our current technological society. The application of LA-ICP-MS presented in Chapter 3 is the forensics analysis of automotive putty and caulking. The elemental analysis of these materials was combined with the use of Principal Components Analysis (PCA). The PCA comparison was able to differentiate the automotive putty samples by manufacturer and lot number. The analysis of caulk was able to show a differentiation based on manufacturer, but no clear differentiation was shown by lot number. This differentiation may allow matching of evidence in the future. This will require many more analyses and the construction of a database made up of many different samples. The 4th chapter was a study of the capabilities of LA-ICP-MS for fast and precise analysis of particle ensembles for nuclear nonproliferation applications. Laser ablation has the ability to spatially resolve particle ensembles which may contain uranium or other actinides from other particles present in a sample. This is of importance in samples obtained from air on filter media. The particle ensembles of interest may be mixed in amongst dust and other particulates. A problem arises when ablating these particle ensembles directly from the filter media. Dust particles other than ones of interest may be accidentally entrained in the aerosol of the ablated particle ensemble. This would cause the analysis to be skewed. The use of a gelatin substrate allows the ablation a particle ensemble without disturbing other particles or the gelatin surface. A method to trap and ablate particles on filter paper using collodion was also investigated. The laser was used to dig through the collodion layer and into the particle ensemble. Both of these methods fix particles to allow spatial resolution of the particle ensembles. The use of vanillic acid as a possible enhancement to ablation was also studied. A vanillic acid coating of the particles fixed on top of the gelatin substrate was not found to have any positive effect on either signal intensity or precision. The mixing of vanillic acid in the collodion solution used to coat the filter paper increased ablation signal intensity by a factor of 4 to 5. There was little effect on precision, though. The collodion on filter paper method and the gelatin method of resolving particles have shown themselves to be possible tools in fighting proliferation of nuclear weapons and material. Future applications of LA-ICP-MS are only limited by the imagination of the investigator. Any material that can be ablated and aerosolized is a potential material for analysis by LA-ICP-MS. Improvements in aerosol transport, ablation chamber design, and laser focusing can make possible the ablation and analysis of very small amounts of material. This may perhaps lead to more possible uses in forensics. A similar method to the one used in Chapter 3 could perhaps be used to match drug residue to the place of origin. Perhaps a link could be made based on the elements leached from the soil by plants used to make drugs. This may have a specific pattern based on where the plant was grown. Synthetic drugs are produced in clandestine laboratories that are often times very dirty. The dust, debris, and unique materials in the lab environment could create enough variance to perhaps match drugs produced there to samples obtained off the street. Even if the match was not strong enough to be evidence, the knowledge that many sa

Messerly, Joshua D.

2008-08-26T23:59:59.000Z

304

The Use of Stable Isotope Labeling and Liquid Chromatography—Tandem Mass Spectrometry Techniques To Simultaneously Determine the Oral and Ophthalmic Bioavailability of Timolol in Dogs  

Science Journals Connector (OSTI)

......liquid chromatography with atmospheric-pressure chemical-ionization...Phillipsburg, NJ). Water (deionized) was generated using a Barnstead generator (Dubuque, IA). Dosing...solution of its maleate salt in water at a concentration of 0......

J.D. Gilbert; T.V. Olah; M.J. Morris; A. Bortnick; J. Brunner

1998-04-01T23:59:59.000Z

305

Influence of Wetting and Mass Transfer Properties of Organic Chemical Mixtures in Vadose Zone Materials on Groundwater Contamination by Nonaqueous Phase Liquids  

SciTech Connect (OSTI)

Previous studies have found that organic acids, organic bases, and detergent-like chemicals change surface wettability. The wastewater and NAPL mixtures discharged at the Hanford site contain such chemicals, and their proportions likely change over time due to reaction-facilitated aging. The specific objectives of this work were to (1) determine the effect of organic chemical mixtures on surface wettability, (2) determine the effect of organic chemical mixtures on CCl4 volatilization rates from NAPL, and (3) accurately determine the migration, entrapment, and volatilization of organic chemical mixtures. Five tasks were proposed to achieve the project objectives. These are to (1) prepare representative batches of fresh and aged NAPL-wastewater mixtures, (2) to measure interfacial tension, contact angle, and capillary pressure-saturation profiles for the same mixtures, (3) to measure interphase mass transfer rates for the same mixtures using micromodels, (4) to measure multiphase flow and interphase mass transfer in large flow cell experiments, all using the same mixtures, and (5) to modify the multiphase flow simulator STOMP in order to account for updated P-S and interphase mass transfer relationships, and to simulate the impact of CCl4 in the vadose zone on groundwater contamination. Results and findings from these tasks and summarized in the attached final report.

Charles J Werth; Albert J Valocchi, Hongkyu Yoon

2011-05-21T23:59:59.000Z

306

Determination of ultratrace boron concentrations in uranium oxide by isotope dilution-thermal ionization mass spectrometry using a simplified separation procedure  

Science Journals Connector (OSTI)

Exhaustive reviews on analytical methodologies and mass spectrometric instrumentation for the determination of boron in different matrices such as biological tissues,...1, 4, 5]. It is an established fact that Isotope

Radhika M. Rao; Ankush R. Parab; K. Sasi Bhushan; Suresh K. Aggarwal

2010-06-01T23:59:59.000Z

307

Note: Laser-induced acoustic desorption/synchrotron vacuum ultraviolet photoionization mass spectrometry for analysis of fragile compounds and heavy oils  

Science Journals Connector (OSTI)

In this work we coupled synchrotron vacuum ultraviolet photoionization (SVUV PI) method with the laser-induced acoustic desorption (LIAD) technique for mass spectrometric analysis. The LIAD technique is a “soft” desorption method which could avoid the degradation of analytes during desorption process. Meanwhile SVUV PI is an efficient “soft” ionization source. The new combination of the “soft” desorption technique and “soft” photoionization method is well suitable to reduce the difficulty for interpreting the mass spectra of the fragile compounds and heavy oils.

Liangyuan Jia; Junjie Weng; Zhongyue Zhou; Fei Qi; Wenyue Guo; Lianming Zhao; Juan Chen

2012-01-01T23:59:59.000Z

308

Journal of Chemical Ecology, Vol. 27, No. 10, October 2001 ( c 2001) IDENTIFICATION, SYNTHESIS, AND FIELD EVALUATION  

E-Print Network [OSTI]

for a monounsaturated acetate. Further analyses by chemical ionization mass spectrometry (CI-MS), vapor-phase infrared of the major component as (E)-8-dodecenyl acetate (E8­12 : Ac). The second constituent was identi- fied- thesis utilizing lithium chemistry. Field tests showed that captures in traps baited with a mixture of E8

Ishida, Yuko

309

Detection of chlorpyrifos-ethyl (Dursban) and its metabolites in urine samples using immunoassays with confirmation by gas chromatography/mass spectrometry  

E-Print Network [OSTI]

by The Dow Chemical Company. ' In 1986, when regulatory measures restricted chlordane usage, Dursban (a 5% formulation of chlorpytifos-ethyl) became popular for termite control. Since chlotpyrifoswthyl is effective against a wide range of insects... (O, O-diethyl phosphate) and DETP (O, O-diethyl phosphorothioate). " A study involving termite control workers concluded that urinary alkyl phosphate levels would be a useful index in biological monitoring of chlorpyrifos exposuie: maximum DETP...

Clewis, Suenda Beth

1995-01-01T23:59:59.000Z

310

Characterization of submicron particles influenced by mixed biogenic and anthropogenic emissions using high-resolution aerosol mass spectrometry: results from CARES  

SciTech Connect (OSTI)

The Carbonaceous Aerosols and Radiative Effects Study (CARES) took place in the Sacramento Valley of California in summer 2010. We present results obtained at Cool, CA, the T1 site of the project ({approx}40 km downwind of urban emissions from Sacramento), where we deployed an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) in parallel with complementary instrumentation to characterize the sources and processes of submicron particles (PM1). Cool is located at the foothill of the Sierra Nevada Mountains, where intense biogenic emissions are periodically mixed with urban outflow transported by daytime southwesterly winds from the Sacramento metropolitan area. The particle mass loading was low (3.0 {micro}gm{sup -3} on average) and dominated by organics (80% of the PM1 mass) followed by sulfate (9.9 %). Organics and sulfate appeared to be externally mixed, as suggested by their different time series (r2 = 0.13) and size distributions. Sulfate showed a bimodal distribution with a droplet mode peaking at {approx}400nm in vacuum aerodynamic diameter (Dva), and a condensation mode at {approx}150 nm, while organics generally displayed a broad distribution in 60-600nm (Dva). New particle formation and growth events were observed almost every day, emphasizing the roles of organics and sulfate in new particle growth, especially that of organics. The organic aerosol (OA) had a nominal formula of C{sub 1}H{sub 1.38}N{sub 0.004}O{sub 0.44}, thus an average organic mass-to-carbon (OM/OC) ratio of 1.70. Two different oxygenated OA (OOA, 90% of total OA mass) and a hydrocarbon-like OA (HOA, 10 %) were identified by Positive matrix factorization (PMF) of the high resolution mass spectra. The more oxidized MO-OOA (O/C = 0.54) corresponded to secondary OA (SOA) primarily influenced by biogenic emissions, while the less oxidized LO-OOA (O/C = 0.42) corresponded to SOA associated with urban transport. The HOA factor corresponded to primary emissions mainly due to local traffic. Twenty three periods of urban plumes from T0 (Sacramento) to T1 (Cool) were identified using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). The average PM1 mass loading was much higher in urban plumes (3.9 {micro}gm{sup -3}) than in air masses dominated by biogenic SOA (1.8 {micro}gm{sup -3}). The change in OA mass relative to CO ({Delta}OA/{Delta}CO) varied in the range of 5-196 {micro}gm{sup -3} ppm{sup -1}, reflecting large variability in SOA production. The highest {Delta}OA/{Delta}CO were reached when urban plumes arrived at Cool in the presence of a high concentration of biogenic volatile organic compounds (BVOCs=isoprene+monoterpenes+2-methyl-3-buten-2- ol [MBO]+methyl chavicol). This ratio, which was 77 {micro}gm{sup -3} ppm{sup -1} on average when BVOCs > 2 ppb, is much higher than when urban plumes arrived in a low biogenic VOCs environment (28 {micro}gm{sup -3} ppm{sup -1} when BVOCs < 0.7 ppb) or during other periods dominated by biogenic SOA (40 {micro}gm{sup -3} ppm{sup -1}). The results from this study demon10 strate that SOA formation is enhanced when anthropogenic emissions interact with biogenic precursors.

Setyan, Ari; Zhang, Qi; Merkel, M.; Knighton, Walter B.; Sun, Y.; Song, Chen; Shilling, John E.; Onasch, Timothy B.; Herndon, Scott C.; Worsnop, Douglas R.; Fast, Jerome D.; Zaveri, Rahul A.; Berg, Larry K.; Wiedensohler, A.; Flowers, B. A.; Dubey, Manvendra K.; Subramanian, R.

2012-09-11T23:59:59.000Z

311

Method for quantitative determination and separation of trace amounts of chemical elements in the presence of large quantities of other elements having the same atomic mass  

DOE Patents [OSTI]

Photoionization via autoionizing atomic levels combined with conventional mass spectroscopy provides a technique for quantitative analysis of trace quantities of chemical elements in the presence of much larger amounts of other elements with substantially the same atomic mass. Ytterbium samples smaller than 10 ng have been detected using an ArF* excimer laser which provides the atomic ions for a time-of-flight mass spectrometer. Elemental selectivity of greater than 5:1 with respect to lutetium impurity has been obtained. Autoionization via a single photon process permits greater photon utilization efficiency because of its greater absorption cross section than bound-free transitions, while maintaining sufficient spectroscopic structure to allow significant photoionization selectivity between different atomic species. Separation of atomic species from others of substantially the same atomic mass is also described.

Miller, C.M.; Nogar, N.S.

1982-09-02T23:59:59.000Z

312

Quantitation by Gas Chromatography-Chemical Ionization Mass Spectrometry of Cyclophosphamide, Phosphoramide Mustard, and Nornitrogen Mustard in the Plasma and Urine of Patients Receiving Cyclophosphamide Therapy  

Science Journals Connector (OSTI)

...Mutagenicity of Urethan (Ethyl Carbamate) Gas in Drosophila melanogaster 1 1 The work...spermatozoa to urethan (ethyl carbamate) gas induced a high frequency of X-linked recessive...observed. Mutagenic activity of urethan gas on mature spermatozoa following 1.5...

I. Jardine; C. Fenselau; M. Appler; M-N. Kan; R. B. Brundrett; M. Colvin

1978-02-01T23:59:59.000Z

313

Dispersive micro-solid phase extraction combined with gas chromatography–chemical ionization mass spectrometry for the determination of N-nitrosamines in swimming pool water samples  

Science Journals Connector (OSTI)

A simple sample pretreatment technique, dispersive micro-solid phase extraction, was applied for the extraction of N-nitrosodimethylamine (NDMA) and other four N-nitrosamines (NAs) from samples of swimming pool w...

Ssu-Chieh Fu; Shin-Hwa Tzing; Hsin-Chang Chen…

2012-02-01T23:59:59.000Z

314

Development of matrix assisted laser desorption ionization-ion mobility-orthogonal time-of-flight mass spectrometry as a tool for proteomics  

E-Print Network [OSTI]

trend line, it is possible to include peptide masses obtained from lower intensity ion signals in a database search at a higher level of confidence, thus obtaining higher percent protein coverage and higher confidence-level protein identification.7... line correlation data in combination with database search results that found no match for m/z 1880 or 2380 (at 2 missed cleavage) was used to tentatively identify the two signals as 14-25+heme and 8-22+heme respectfully, where no such identification...

Ruotolo, Brandon Thomas

2005-08-29T23:59:59.000Z

315

LipidMiner: A Software for Automated Identification and Quantification of Lipids from Multiple Liquid Chromatography-Mass Spectrometry Data Files  

SciTech Connect (OSTI)

We have developed a tool for automated, high-throughput analysis of LC-MS/MS data files, which greatly simplifies LC-MS based lipidomics analysis. Our results showed that LipidMiner is accurate and comprehensive in identification and quantification of lipid molecular species. In addition, the workflow implemented in LipidMiner is not limited to identification and quantification of lipids. If a suitable metabolite library is implemented in the library matching module, LipidMiner could be reconfigured as a tool for general metabolomics data analysis. It is of note that LipidMiner currently is limited to singly charged ions, although it is adequate for the purpose of lipidomics since lipids are rarely multiply charged,[14] even for the polyphosphoinositides. LipidMiner also only processes file formats generated from mass spectrometers from Thermo, i.e. the .RAW format. In the future, we are planning to accommodate file formats generated by mass spectrometers from other predominant instrument vendors to make this tool more universal.

Meng, Da; Zhang, Qibin; Gao, Xiaoli; Wu, Si; Lin, Guang

2014-04-30T23:59:59.000Z

316

Standard test method for analysis of isotopic composition of uranium in nuclear-grade fuel material by quadrupole inductively coupled plasma-mass spectrometry  

E-Print Network [OSTI]

1.1 This test method is applicable to the determination of the isotopic composition of uranium (U) in nuclear-grade fuel material. The following isotopic weight percentages are determined using a quadrupole inductively coupled plasma-mass spectrometer (Q-ICP-MS): 233U, 234U, 235U, 236U, and 238U. The analysis can be performed on various material matrices after acid dissolution and sample dilution into water or dilute nitric (HNO3) acid. These materials include: fuel product, uranium oxide, uranium oxide alloys, uranyl nitrate (UNH) crystals, and solutions. The sample preparation discussed in this test method focuses on fuel product material but may be used for uranium oxide or a uranium oxide alloy. Other preparation techniques may be used and some references are given. Purification of the uranium by anion-exchange extraction is not required for this test method, as it is required by other test methods such as radiochemistry and thermal ionization mass spectroscopy (TIMS). This test method is also described i...

American Society for Testing and Materials. Philadelphia

2000-01-01T23:59:59.000Z

317

Liquid Microjunction Surface Sampling Coupled with High-Pressure Liquid Chromatography-Electrospray Ionization-Mass Spectrometry for Analysis of Drugs and Metabolites in Whole-Body Thin Tissue Sections  

SciTech Connect (OSTI)

In this work, a commercially available autosampler was adapted to perform direct liquid microjunction (LMJ) surface sampling followed by a high-pressure liquid chromatography (HPLC) separation of the extract components and detection with electrospray ionization mass spectrometry (ESI-MS). To illustrate the utility of coupling a separation with this direct liquid extraction based surface sampling approach, four different organs (brain, lung, kidney, and liver) from whole-body thin tissue sections of propranolol dosed and control mice were examined. The parent drug was observed in the chromatograms of the surface sampling extracts from all the organs of the dosed mouse examined. In addition, two isomeric phase II metabolites of propranolol (an aliphatic and an aromatic hydroxypropranolol glucuronide) were observed in the chromatograms of the extracts from lung, kidney, and liver. Confirming the presence of one or the other or both of these glucuronides in the extract from the various organs was not possible without the separation. These drug and metabolite data obtained using the LMJ surface sampling/HPLC-MS method and the results achieved by analyzing similar samples by conventional extraction of the tissues and subsequent HPLC-MS analysis were consistent.

Kertesz, Vilmos [ORNL; Van Berkel, Gary J [ORNL

2010-01-01T23:59:59.000Z

318

Accurate determination of Curium and Californium isotopic ratios by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) in 248Cm samples for transmutation studies  

SciTech Connect (OSTI)

The French Atomic Energy Commission has carried out several experiments including the mini-INCA (INcineration of Actinides) project for the study of minor-actinide transmutation processes in high intensity thermal neutron fluxes, in view of proposing solutions to reduce the radiotoxicity of long-lived nuclear wastes. In this context, a Cm sample enriched in {sup 248}Cm ({approx}97 %) was irradiated in thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). This work describes a quadrupole ICP-MS (ICP-QMS) analytical procedure for precise and accurate isotopic composition determination of Cm before sample irradiation and of Cm and Cf after sample irradiation. The factors that affect the accuracy and reproducibility of isotopic ratio measurements by ICP-QMS, such as peak centre correction, detector dead time, mass bias, abundance sensitivity and hydrides formation, instrumental background, and memory blank were carefully evaluated and corrected. Uncertainties of the isotopic ratios, taking into account internal precision of isotope ratio measurements, peak tailing, and hydrides formations ranged from 0.3% to 1.3%. This uncertainties range is quite acceptable for the nuclear data to be used in transmutation studies.

Gourgiotis, A.; Isnard, H.; Aubert, M.; Dupont, E.; AlMahamid, I.; Cassette, P.; Panebianco, S.; Letourneau, A.; Chartier, F.; Tian, G.; Rao, L.; Lukens, W.

2011-02-01T23:59:59.000Z

319

Thermal Desorption-Gas Chromatography or Gas Chromatography-Mass Spectrometry for Analysis of Semi-Volatile Compounds on Atmospheric Particulate Matters  

Science Journals Connector (OSTI)

Abstract A thermal desorption (TD) device was developed and coupled to gas chromatograph (GC) or gas chromatograph-mass spectrometer (GC-MS) for the qualitative and quantitative analysis of semi-volatile organic compounds on atmospheric particulate matters (PM). The TD was operated by direct heating and placed on the top of GC injector, leading to high heating rate and easy transfer of analytes to GC without re-focusing of analytes by cold trap. The materials used for supporting PM samples, desorption temperature and time, and types of sample injection were investigated for the detection of sixteen polycyclic aromatic hydrocarbons (PAHs) and nine n-alkanes. The limits of detection of the proposed TD-GC method were in the range of 0.014–0.094 ng for PAHs, and 0.016–0.026 ng for n-alkanes, with coefficients of correlation above 0.9975. The TD-GC method was applied to the determination of trace \\{PAHs\\} and n-alkanes on PM10 samples from three cities. The recoveries were in the range of 95%–135% (PAHs) and 95%–115% (n-alkanes). Finally, the TD was coupled to GC-MS for comparison of the contents of \\{PAHs\\} and n-alkanes on \\{PMx\\} with different particulate size (x = 10, 5, 2, 1, 0.5, 0.25, 0.1).

Hu MENG; Jing-Hong ZHAO; Chun-Feng DUAN; Liang HAO; Ya-Feng GUAN

2014-01-01T23:59:59.000Z

320

Bioaccumulation Potential Of Air Contaminants: Combining Biological Allometry, Chemical Equilibrium And Mass-Balances To Predict Accumulation Of Air Pollutants In Various Mammals  

SciTech Connect (OSTI)

In the present study we develop and test a uniform model intended for single compartment analysis in the context of human and environmental risk assessment of airborne contaminants. The new aspects of the model are the integration of biological allometry with fugacity-based mass-balance theory to describe exchange of contaminants with air. The developed model is applicable to various mammalian species and a range of chemicals, while requiring few and typically well-known input parameters, such as the adult mass and composition of the species, and the octanol-water and air-water partition coefficient of the chemical. Accumulation of organic chemicals is typically considered to be a function of the chemical affinity forlipid components in tissues. Here, we use a generic description of chemical affinity for neutral and polar lipids and proteins to estimate blood-air partition coefficients (Kba) and tissue-air partition coefficients (Kta) for various mammals. This provides a more accurate prediction of blood-air partition coefficients, as proteins make up a large fraction of total blood components. The results show that 75percent of the modeled inhalation and exhalation rate constants are within a factor of 2 from independent empirical values for humans, rats and mice, and 87percent of the predicted blood-air partition coefficients are within a factor of 5 from empirical data. At steady-state, the bioaccumulation potential of air pollutants is shown to be mainly a function of the tissue-air partition coefficient and the biotransformation capacity of the species and depends weakly on the ventilation rate and the cardiac output of mammals.

Veltman, Karin; McKone, Thomas E.; Huijbregts, Mark A.J.; Hendriks, A. Jan

2009-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Simultaneous determination of triazine herbicides in rice by high-performance liquid chromatography coupled with high resolution and high mass accuracy hybrid linear ion trap-orbitrap mass spectrometry  

Science Journals Connector (OSTI)

A method was developed for the simultaneous determination of 10 triazine herbicides (cyanazine, simazine, simetryn, metribuzin, atrazine, ametryn, terbuthylazine, prometryn, terbutryn, and dimethametryn) in rice samples by high resolution and high mass accuracy hybrid linear ion trap-Orbitrap mass spectrometer. After extraction with acetonitrile and evaporation, the herbicides were redissolved in n-hexane and purified on a Florisil solid-phase extraction column. All compounds were separated within 12 min, producing more than 11 data points for each herbicide and high mass accuracy quantified ions which the mass errors of absolute value were less than 1.9 ppm in pure solution and 2.1 ppm in the matrix-matched standards solution. The method was validated in terms of the limits of detection and the limits of quantification. The linearity was satisfactory, with a correlation coefficient of >0.9975. Precision and recovery studies were evaluated at three concentration levels for Japonica, Indica, and Glutinous rice matrix. The mean recoveries obtained for all analytes in spiked Xiushui 03, Liangyoupeijiu, and Taihunuo rice samples were 83.3–99.0%, 82.0–99.7%, and 84.2–99.4%, respectively, with relative standard deviation in range 1.7–10.6%, 1.2–10.7%, and 1.9–11.6% for spiked rice samples, respectively. The intra-day precision (n = 5) for the 10 herbicides in rice samples spiked at an intermediate level was between 2.8% and 7.9%, and the inter-day precision over 10 days (n = 10) was between 5.5% and 15.9%.

Ren-Xiang Mou; Ming-Xue Chen; Zhao-Yun Cao; Zhi-Wei Zhu

2011-01-01T23:59:59.000Z

322

Anthropogenic 236U at Rocky Flats, Ashtabula river harbor, and Mersey estuary: three case studies by sector inductively coupled plasma mass spectrometry  

Science Journals Connector (OSTI)

236U (t1/2=2.3×107 y) is formed as a result of thermal neutron capture by 235U. In naturally occurring U ores, where a high neutron flux is present from spontaneous fission of 238U, 236U/238U atom ratios are ~10?4 ppm. In the natural Earth’s crust, unaffected by nuclear fallout, these ratios are expected to be on the order of 10?8 ppm. Reactor-irradiated U, however, exhibits high 236U/238U atom ratios approaching 104 ppm. As a result, the presence of very small quantities of reactor-irradiated U will significantly enhance the ‘background’ 236U/238U atom ratio. When sufficiently elevated 236U/238U ratios are present, the determination of 236U/238U by rapid inductively coupled plasma mass spectrometric (ICPMS) methods is attractive. We have used sector ICPMS at medium resolving power (R=3440) to measure 236U/238U atom ratios with a determination limit of 0.2 ppm. The limiting factors in the measurement are the 235U1H+ isobar and background signal at m/z 236 arising from the 238U+ peak tail. Based upon the analysis of replicates and considerations of possible systematic errors, uncertainties of ±5% are found for 236U/238U atom ratios of 1?100 ppm. This procedure has been demonstrated in studies of anthropogenic 236U in the environment at three locations: (a) offsite soils from the vicinity of the Rocky Flats Environmental Technology site (Golden, Colorado, USA); (b) sediments from the Ashtabula River (Ohio, USA); and (c) sediments from the Mersey estuary (Liverpool, UK). In each of these three locations, definite plumes of elevated 236U/238U are identified and characterized. Maximum 236U/238U atom ratios observed in RFETS-vicinity soils, the Ashtabula River, and the Mersey Estuary are 2.8, 140, and 4.4 ppm, respectively.

M.E Ketterer; K.M Hafer; C.L Link; C.S Royden; W.J Hartsock

2003-01-01T23:59:59.000Z

323

Applications of High-Resolution Electrospray Ionization Mass...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

High-Resolution Electrospray Ionization Mass Spectrometry to Measurements of Average Oxygen to Carbon Ratios in Applications of High-Resolution Electrospray Ionization Mass...

324

Nuclear Masses in Astrophysics  

E-Print Network [OSTI]

Among all nuclear ground-state properties, atomic masses are highly specific for each particular combination of N and Z and the data obtained apply to a variety of physics topics. One of the most crucial questions to be addressed in mass spectrometry of unstable radionuclides is the one of understanding the processes of element formation in the Universe. To this end, accurate atomic mass values of a large number of exotic nuclei participating in nucleosynthesis are among the key input data in large-scale reaction network calculations. In this paper, a review on the latest achievements in mass spectrometry for nuclear astrophysics is given.

Christine Weber; Klaus Blaum; Hendrik Schatz

2008-12-09T23:59:59.000Z

325

The role of the acquisition methods in the analysis of natural and synthetic steroids and cholic acids by gas chromatography–mass spectrometry  

Science Journals Connector (OSTI)

An exhaustive GC–MS acquisition study was performed, for the simultaneous analysis of natural and synthetic steroids and cholic acids (in order to insert them into the last tierce of our multiresidue analysis system), such as androsterone, ?-estradiol, transdehydroandro-sterone, transdehyroandrosterone, mestranol, dihydrotestosterone, ethinylestradiol, testosterone, norethisterone, estriol, 4-androstene-3,17-dione, gestodene, levonorgestrel, etonogestrel, coprostanol, progesterone, cholesterol, medroxyprogesterone-acetate, lithocholic acid, stigmasterol, cholic acid, chenodeoxycholic acid, ?-sitosterol, ursodeoxycholic acid, 3-hydroxy-7-ketocholic acid and dehydrocholic acid, in total 26 compounds. As novelties to the field, for the trimethylsilyl (TMS) oxime ether/ester derivatives of steroids and cholic acids, at first, a tandem mass spectrometric (MS/MS), multiple reaction monitoring (MRM) type acquisition method has been developed in a single run; also for the first time, the three acquisition techniques, the full scan (FS), the selective ion monitoring (SIM), in our case the multiple ion monitoring (MIM) and the currently optimized MRM methods, have been compared; all three, in parallel, under strictly the same derivatization/instrumental conditions, both in matrix free solutions and municipal wastewater from two Hungarian wastewater treatment plants (WWTPs). Critical evaluation of the three acquisition protocols was collated on their analytical performances and validated under the same conditions. The data of six point calibration curves for FS, MIM and MRM methods, showed that both R2 (0.9995, 0.9858, 0.9975) and RSD (5.3, 5.8, 5.0), for two parallel derivatizations, each injected three times, proved to be independent of the acquisition processes. Whereas, for the method limit of quantification (LOQ) and the instrument limit of quantification (ILQ) values showed considerable differences. LOQ data, were decreasing in the FS, MIM, MRM line (expressed in ng/L), for all steroids and cholic acids. The same trend was determined in terms of the ILQ values. The practical utility of the optimized acquisition techniques was confirmed by the quantitation of the steroids and cholic acids contents of wastewater samples. Results confirmed the importance of the MRM acquisition method, even in comparison to the MIM one: with particular interest in selected cases: avoiding the extreme overestimation of the ?-estradiol (156–1325%) and that of the ethinylestradiol (582–831%) concentrations in the wastewater samples.

N. Andrási; A. Helenkár; A. Vasanits-Zsigrai; Gy. Záray; I. Molnár-Perl

2011-01-01T23:59:59.000Z

326

Chemical Characterization of Crude Petroleum Using Nanospray...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Coupled with High-Resolution Abstract: Nanospray desorption electrospray ionization (nano-DESI) combined with high-resolution mass spectrometry was used for the first time for...

327

Ultraviolet photodissociation enhances top?down mass...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ultraviolet photodissociation enhances top-down mass spectrometry as demonstrated on green fluorescent protein variants Xibei Dang 1,2 and Nicolas L. Young 1 1 Ion Cyclotron...

328

Determination of actinide elements at femtogram per gram levels in environmental samples by on-line solid phase extraction and sector-field-inductively coupled plasma-mass spectrometry  

Science Journals Connector (OSTI)

An on-line solid phase extraction method has been developed for the determination of 232Th, 237Np, 238U, 239Pu, 240Pu, 241Am and 243Am in biological certified reference material using a column containing TRU-Spec™ resin coupled with sector-field inductively coupled plasma-mass spectrometry. Absolute detection limits were 0.7, 0.85, 0.6, and 0.65 fg for 237Np, 239Pu, 241Am and 243Am, respectively. The 239Pu was determined in NIST Human Liver (963±297 fg g?1 compared with a certified value of 848±161 fg g?1) using a dry and wet ashing sample preparation method, and in a spiked cabbage reference material (394±54 fg g?1 compared to an indicative value of 467 fg g?1) using microwave digestion. Sequential separation of Pu and U was achieved by on-column reduction of Pu with titanium(III) chloride and elution in 4 M \\{HCl\\} to facilitate the determination of 239Pu in samples containing high levels of 238U, thereby eliminating the interference of 238U1H+ at m/z 239. The sequential elution procedure was used to determine 239Pu in NIST human lung (814±55 fg g?1 compared with a certified range of 227–951 fg g?1) and NIST Rocky Flats Soil (2423±137 fg g?1 compared with a certified value of 3307±248 fg g?1).

Jason B Truscott; Phil Jones; Ben E Fairman; E.Hywel Evans

2001-01-01T23:59:59.000Z

329

HRI catalytic two-stage liquefaction (CTSL) process materials: chemical analysis and biological testing  

SciTech Connect (OSTI)

This report presents data from the chemical analysis and biological testing of coal liquefaction materials obtained from the Hydrocarbon Research, Incorporated (HRI) catalytic two-stage liquefaction (CTSL) process. Materials from both an experimental run and a 25-day demonstration run were analyzed. Chemical methods of analysis included adsorption column chromatography, high-resolution gas chromatography, gas chromatography/mass spectrometry, low-voltage probe-inlet mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The biological activity was evaluated using the standard microbial mutagenicity assay and an initiation/promotion assay for mouse-skin tumorigenicity. Where applicable, the results obtained from the analyses of the CTSL materials have been compared to those obtained from the integrated and nonintegrated two-stage coal liquefaction processes. 18 refs., 26 figs., 22 tabs.

Wright, C.W.; Later, D.W.

1985-12-01T23:59:59.000Z

330

Chip-based genotyping by mass spectrometry  

Science Journals Connector (OSTI)

...use. A piezo-electric...using a piezo-electric pipette...molecules. A piezo-electric pipette was used for...indicating uneven distribution...the Department of Energy and National Institutes of Health planning groups ( 1998...

Kai Tang; Dong-Jing Fu; Dominique Julien; Andreas Braun; Charles R. Cantor; Hubert Köster

1999-01-01T23:59:59.000Z

331

Improvements in Inductively Coupled Plasma - Mass Spectrometry...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Simpler sampling can reduce the hazards, costs and complexity of site assessment, and that's what's on the way for an established analytical technique. Scientists are modifying...

332

Signatures for Mass Spectrometry Data Quality  

SciTech Connect (OSTI)

Ensuring data quality and proper instrument functionality is a prerequisite for scientific investigation. Manual validation for quality assurance is time consuming, expensive and subjective. Metrics for describing various features of LC-MS data have been developed to assist operators in discriminating poor (out of control) and good (in control) datasets. However, the wide variety of instrument specifications and LC-MS configurations precludes applying a simple range of acceptable values or cutoffs for such metrics. We explored a variety of statistical modeling approaches to predict the quality of LC-MS data. Using 1164 manually classified quality control (QC) LC-MS datasets, we fit logistic regression classification models to the QC data to predict whether a dataset is in or out of control. Model parameters were optimized by minimizing a loss function that accounts for the tradeoff between false positive and false negative errors. The optimal logistic regression classifier models detected bad data sets with high sensitivity (i.e. low false negative rate) while maintaining high specificity (i.e. controlling the false positive rate). As an example, predictions for Velos-Orbitrap instrumentation data had a sensitivity of 93.7% in detecting out of control datasets with a false positive rate of 8.3%. In comparison, we investigated the performance of several single metrics in predicting dataset quality. While maintaining a sensitivity of 93.7%, the corresponding false positive rates for these single-metric models unacceptably ranged from 32% to 97.7%. Finally, we evaluated the performance of the

Amidan, Brett G.; Orton, Daniel J.; Lamarche, Brian L.; Monroe, Matthew E.; Moore, Ronald J.; Venzin, Alexander M.; Smith, Richard D.; Sego, Landon H.; Tardiff, Mark F.; Payne, Samuel H.

2014-03-10T23:59:59.000Z

333

Aerosol mass spectrometry systems and methods  

DOE Patents [OSTI]

A system according to one embodiment includes a particle accelerator that directs a succession of polydisperse aerosol particles along a predetermined particle path; multiple tracking lasers for generating beams of light across the particle path; an optical detector positioned adjacent the particle path for detecting impingement of the beams of light on individual particles; a desorption laser for generating a beam of desorbing light across the particle path about coaxial with a beam of light produced by one of the tracking lasers; and a controller, responsive to detection of a signal produced by the optical detector, that controls the desorption laser to generate the beam of desorbing light. Additional systems and methods are also disclosed.

Fergenson, David P.; Gard, Eric E.

2013-08-20T23:59:59.000Z

334

Improving liquid chromatography-mass spectrometry sensitivity...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

sensitivity using a subambient pressure ionization with nanoelectrospray (SPIN Abstract: In this work the Subambient Pressure Ionization with Nanoelectrospray (SPIN) ion...

335

Chemical Analysis of Diesel Engine Nanoparticles Using a Nano-DMA/Thermal Desorption Particle Beam Mass Spectrometer  

Science Journals Connector (OSTI)

Modern combustion engines burn cleaner and produce less particulate mass than older models, but it has also been observed that some engines, for example, diesels, emit high number concentrations of a subset of fine particles called nanoparticles (diameter cycle, turbocharged diesel engine that produced a peak torque of 350 N-m at an intermediate engine speed of 1400 rpm, which is generally used for short-duration work periods of heavy lifting or material handling. ... However, general trends from past studies can be applied to the analysis of this work. ...

Herbert J. Tobias; Derek E. Beving; Paul J. Ziemann; Hiromu Sakurai; Miriam Zuk; Peter H. McMurry; Darrick Zarling; Robert Waytulonis; David B. Kittelson

2001-04-25T23:59:59.000Z

336

LTQ-XL mass spectrometry proteome analysis expands the Pseudomonas aeruginosa AmpR regulon to include cyclic di-GMP phosphodiesterases and phosphoproteins, and identifies novel open reading frames  

Science Journals Connector (OSTI)

Abstract Pseudomonas aeruginosa is well known for its antibiotic resistance and intricate regulatory network, contributing to its success as an opportunistic pathogen. This study is an extension of our transcriptomic analyses (microarray and RNA-Seq) to understand the global changes in PAO1 upon deleting a gene encoding a transcriptional regulator AmpR, in the presence and absence of ?-lactam antibiotic. This study was performed under identical conditions to explore the proteome profile of the ampR deletion mutant (PAO?ampR) using LTQ-XL mass spectrometry. The proteomic data identified ~ 53% of total PAO1 proteins and expanded the master regulatory role of AmpR in determining antibiotic resistance and multiple virulence phenotypes in P. aeruginosa. AmpR proteome analysis identified 853 AmpR-dependent proteins, which include 102 transcriptional regulators and 21 two-component system proteins. AmpR also regulates cyclic di-GMP phosphodiesterases (PA4367, PA4969, PA4781) possibly affecting major virulence systems. Phosphoproteome analysis also suggests a significant role for AmpR in Ser, Thr and Tyr phosphorylation. These novel mechanisms of gene regulation were previously not associated with AmpR. The proteome analysis also identified many unannotated and misannotated \\{ORFs\\} in the P. aeruginosa genome. Thus, our data sheds light on important virulence regulatory pathways that can potentially be exploited to deal with P. aeruginosa infections. Biological significance The AmpR proteome data not only confirmed the role of AmpR in virulence and resistance to multiple antibiotics, but also expanded the perimeter of AmpR regulon. The data presented here points to the role of AmpR in regulating cyclic di-GMP levels and phosphorylation of Ser, Thr and Tyr, adding another dimension to the regulatory functions of AmpR. We also identify some previously unannotated/misannotated \\{ORFs\\} in the P. aeruginosa genome, indicating the limitations of existing ORF analyses software. This study will contribute towards understanding complex genetic organization of P. aeruginosa. Whole genome proteomic picture of regulators at higher nodal positions in the regulatory network will not only help us link various virulence phenotypes but also design novel therapeutic strategies.

Hansi Kumari; Senthil K. Murugapiran; Deepak Balasubramanian; Lisa Schneper; Massimo Merighi; David Sarracino; Stephen Lory; Kalai Mathee

2014-01-01T23:59:59.000Z

337

Chemical speciation of radionuclides migrating in groundwaters  

SciTech Connect (OSTI)

In order to more accurately predict the rates and mechanisms of radionuclide migration from low-level waste disposal facilities via groundwater transport, ongoing studies are being conducted at field sites at Chalk River Laboratories to identify and characterize the chemical speciation of mobile, long-lived radionuclides migrating in groundwaters. Large-volume water sampling techniques are being utilized to separate and concentrate radionuclides into particular, cationic, anionic, and nonionic chemical forms. Most radionuclides are migrating as soluble, anionic species that appear to be predominantly organoradionuclide complexes. Laboratory studies utilizing anion exchange chromatography have separated several anionically complexed radionuclides, e.g., {sup 60}Co and {sup 106}Ru, into a number of specific compounds or groups of compounds. Further identification of the anionic organoradionuclide complexes is planned utilizing high resolution mass spectrometry. Large-volume ultra-filtration experiments are characterizing the particulate forms of radionuclides being transported in these groundwaters.

Robertson, D.; Schilk, A.; Abel, K.; Lepel, E.; Thomas, C.; Pratt, S. [Pacific Northwest Lab., Richland, WA (United States); Cooper, E.; Hartwig, P.; Killey, R. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.

1994-04-01T23:59:59.000Z

338

Decommissioning samples from the Ft. Lewis, WA, solvent refined coal pilot plant: chemical analysis and biological testing  

SciTech Connect (OSTI)

This report presents the results from chemical analyses and limited biological assays of three sets of samples from the Ft. Lewis, WA solvent refined coal (SRC) pilot plant. The samples were collected during the process of decommissioning this facility. Chemical composition was determined for chemical class fractions of the samples by using high-resolution gas chromatography (GC), high-resolution GC/mass spectrometry (MS) and high-resolution MS. Biological activity was measuring using both the histidine reversion microbial mutagenicity assay with Salmonella typhimurium, TA98 and an initiation/promotion mouse-skin tumorigenicity assay. 19 refs., 7 figs., 27 tabs.

Weimer, W.C.; Wright, C.W.

1985-10-01T23:59:59.000Z

339

Chemical species of migrating radionuclides at a shallow land low-level radioactive-waste burial site  

SciTech Connect (OSTI)

A research program at the Maxey Flats, Kentucky (U.S.A.) waste disposal site has been undertaken to define the chemical species contributing to the migration or retention of radionuclides contained in waste buried at that site. An experimental trench and inert atmosphere sampling wells were installed to sample water for determination of the chemical species of migrating radionuclides. The organic ligands are studied by gas chromatography, steric exclusion chromatography and mass spectrometry; and the data correlated with specific radionuclide counting data to determine precise chemical species. Preliminary data are reported in the text.

Kirby, L.J.; Toste, A.P.; Wilkerson, C.L.

1981-01-01T23:59:59.000Z

340

Physical and chemical characteristics of an interesterified blend of butterfat and cottonseed oil with possible industrial applications  

E-Print Network [OSTI]

: dilatometry, glyceride compositional analysis, thin layer chromatography, gas liquid chromatography, mass spectrometry, and pancreatic lipase hydrolysis. physical/Chemical properties of the Modified pats Use of official methods of the American Oil... butterfat, cottonseed oil, the blend, the interesterified blend, and cheese. The following tests were conducted: Free fatty acids A. O. C. S. official method Ca 5a-40 was used. The molten samples were well mixed and a sample size of 28. 2 g of each...

Rashidi, Nabil

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Electrospray ionization mass spectrometric characterization of acrylamide adducts to hemoglobin  

SciTech Connect (OSTI)

The most common procedure to identify hemoglobin adducts has been to cleave the adducts from the protein and characterize the adducting species, by, for example, derivatization and gas chromatography/mass spectrometry. To extend these approaches we used electrospray ionization mass spectrometry (ESI-MS) to characterize adducted hemoglobin. For this we incubated [[sup 14]C]acrylamide with the purified human hemoglobin (type A[sub 0]) under conditions that yielded high adduct levels. When the hemoglobin was separated by reversed-phase high-performance liquid chromatography (HPLC), 65% of the radioactivity copurified with the [beta]-subunit. Three adducted species were prominent in the ESI mass spectrum of the intact [beta]-subunit, indicating acrylamide adduction (i.e., mass increase of 71 Da) and two addition unidentified moieties with mass increments of 102 and 135 Da. Endoproteinase Glu-C digestion of the adducted [beta]-subunit resulted in a peptide mixture that, upon reversed-phase HPLC separation, provided several radiolabeled peptides. Using ESI-MS we identified these as the V[sub 91-101] and V[sub 102-122] peptides that represent the cysteine-containing peptides of the [beta]-subunit. These results provide definitive information on acrylamide-modified human hemoglobin and demonstrate that ESI-MS provides valuable structure information on chemically adducted proteins. 30 refs., 9 figs., 3 tabs.

Springer, D.L.; Goheen, S.C.; Edmonds, C.G. (Pacific Northwest Lab., Richland, WA (United States)); Bull, R.J.; Sylvester, D.M. (Washington State Univ., Pullman, WA (United States))

1993-01-01T23:59:59.000Z

342

Gas chromatographic-mass spectrometric determination of benzo[a]pyrene and chrysene diol epoxide globin adducts in humans.  

Science Journals Connector (OSTI)

...Orlando, FL Abstract 5104: Serum metabolomic profiles acquired by gas chromatography-mass spectrometry (GC-MS) distinguish patients...disease. Accompanying clinical data were collected prospectively. Gas chromatography-mass spectrometry (GC-MS) spectra were acquired...

A A Melikian; P Sun; C Pierpont; S Coleman; S S Hecht

1997-10-01T23:59:59.000Z

343

Application of Surface Chemical Analysis Tools for Characterization...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

photoelectron spectroscopy (XPS); time of flight secondary ion mass spectrometry (TOF-SIMS); low energy ion scattering (LEIS); and scanning probe microscopy (SPM), including...

344

2, 21672208, 2002 Chemical mass  

E-Print Network [OSTI]

results simulating water soluble organic compound production by gas-to-particle conversion an important role in the atmosphere for several reasons. They transport material through the atmosphere, affect

Boyer, Edmond

345

CHEMICAL SENSORS School of Chemistry and Biochemistry  

E-Print Network [OSTI]

CHEMICAL SENSORS CHEM 6282 School of Chemistry and Biochemistry Chemical sensors theory of chemical recognition, electrochemical, optical, mass sensors and data reduction. Text: J. Janata, "Principles of Chemical Sensors", 2010 Springer NOTE: GT Library purchased an e

Sherrill, David

346

12.141 Electron Microprobe Analysis by Wavelength Dispersive X-ray Spectrometry, January IAP 2010  

E-Print Network [OSTI]

This lab-oriented course introduces the student to the subject of X-ray spectrometry and micro-scale chemical quantitative analysis of solid samples through an intensive series of hands-on laboratory exercises that use the ...

Chatterjee, Nilanjan

2010-01-01T23:59:59.000Z

347

The use of HPTLC and Direct Analysis in Real Time-Of-Flight Mass Spectrometry (DART-TOF-MS) for rapid analysis of degradation by oxidation and sonication of an azo dye  

E-Print Network [OSTI]

-oxidation of an azo dye, methyl red sodium salt (MRSS) as a model compound. Initial and final UV-Vis spectra showed of pollutants in wastewater. These effluents may cause environmental, visual and chemical pollution. Amongst

Paris-Sud XI, Université de

348

Chemical compounds and toxicological assessments of drinking water stored in polyethylene terephthalate (PET)  

E-Print Network [OSTI]

Chemical compounds and toxicological assessments of drinking water stored in polyethyleneMS, gas chromatographyemass spectrometry; HDPE, high density polyethylene; HULYs, human blood lymphocytes

Short, Daniel

349

Quantification of Methadone and its Metabolite 2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine in Third Instar Larvae of Lucilia sericata (Diptera: Calliphoridae) Using Liquid Chromatography-Tandem Mass Spectrometry  

Science Journals Connector (OSTI)

......Sensitivity and Specificity Substance Abuse Detection methods Tandem Mass...substances such as drugs-of-abuse, ethanol, or benzodiazepines...detected in human remains of a young man suspected to consume heroin...importance in Medellin, Colombia. Internet J. Forensic Med. Toxicol......

Matthias Gosselin; Maria del Mar Ramirez Fernandez; Sarah M.R. Wille; Nele Samyn; Gert De Boeck; Benoit Bourel

2010-09-01T23:59:59.000Z

350

Standard practices for dissolving glass containing radioactive and mixed waste for chemical and radiochemical analysis  

E-Print Network [OSTI]

1.1 These practices cover techniques suitable for dissolving glass samples that may contain nuclear wastes. These techniques used together or independently will produce solutions that can be analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS), radiochemical methods and wet chemical techniques for major components, minor components and radionuclides. 1.2 One of the fusion practices and the microwave practice can be used in hot cells and shielded hoods after modification to meet local operational requirements. 1.3 The user of these practices must follow radiation protection guidelines in place for their specific laboratories. 1.4 Additional information relating to safety is included in the text. 1.5 The dissolution techniques described in these practices can be used for quality control of the feed materials and the product of plants vitrifying nuclear waste materials in glass. 1.6 These pr...

American Society for Testing and Materials. Philadelphia

2000-01-01T23:59:59.000Z

351

Polyfluoroalkyl chemicals in house dust  

SciTech Connect (OSTI)

We developed a high throughput analytical method using on-line solid phase extraction coupled with isotope dilution high-performance liquid chromatography-tandem mass spectrometry (on-line SPE-HPLC-MS/MS) to simultaneously determine the concentrations of 17 polyfluoroalkyl chemicals (PFCs) in house dust. The sample preparation includes dispersion of the dust samples in 0.1 M formic acid:MeOH (1:1), followed by agitation and filtration, addition of the isotope-labeled internal standard solution to the filtrate, and analysis by on-line SPE-HPLC-MS/MS. The limits of quantitation were <4.0 ng/g. The method accuracies ranged between 73.2% and 100.2% for the different analytes at two spike levels. We confirmed the validity of the method by analyzing 39 household dust samples collected in 2004. Of the 17 PFCs measured, 6 of them-perfluorobutane sulfonate (PFBuS), N-ethyl-perfluorooctane sulfonamide, 2-(N-ethyl-perfluorooctane sulfonamido) acetic acid (Et-PFOSA-AcOH), 2-(N-methyl-perfluorooctane sulfonamido) ethanol (Me-PFOSA-EtOH), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS)-had detection frequencies >70%. We detected PFOS, PFBuS, and PFHxS at the highest median concentration, followed by Et-PFOSA-AcOH and Me-PFOSA-EtOH.

Kato, Kayoko [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F53, Atlanta, GA 30341 (United States)] [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F53, Atlanta, GA 30341 (United States); Calafat, Antonia M., E-mail: acalafat@cdc.gov [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F53, Atlanta, GA 30341 (United States); Needham, Larry L. [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F53, Atlanta, GA 30341 (United States)] [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F53, Atlanta, GA 30341 (United States)

2009-07-15T23:59:59.000Z

352

E-Print Network 3.0 - atomic masses library Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

21 ATOMS... ... Source: UK Fusion Center at Culham (UKAEA) Collection: Plasma Physics and Fusion 27 Modeling Mass Spectrometry-Based Protein Analysis Jan Eriksson and David Feny...

353

The SFM/ToF-SIMS combination for advanced chemically-resolved analysis at the nanoscale  

Science Journals Connector (OSTI)

Abstract The combination of Time-of-flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Scanning Force Microscopy (SFM) allows the 3D-compositional analysis of samples or devices. Typically, the topographical data obtained by SFM is used to determine the initial sample topography and the absolute depth of the ToF-SIMS analysis. Here ToF-SIMS and SFM data sets obtained on 2 prototypical samples are explored to go beyond conventional 3D-compositional analysis. SFM topographical and material contrast maps are combined with ToF-SIMS retrospective analysis to detect features that would have escaped a conventional ToF-SIMS data analysis. In addition, SFM data is used to extrapolate the chemical information beyond the spatial resolution of ToF-SIMS, allowing the mapping of the chemical composition at the nanoscale.

Laetitia Bernard; Jakob Heier; Wolfgang Paul; Hans J. Hug

2014-01-01T23:59:59.000Z

354

Mass Spectrometry and Density Functional Theory Characterizations of DNA Modifications  

E-Print Network [OSTI]

to fully characterize synthetic DNA bearing cisplatin cross-in the hydrolysis of synthetic DNA as part of the MS-basedlink yield from synthetic DNA harboring 5-X-pyrimidines,

Williams, Renee Therese

2012-01-01T23:59:59.000Z

355

Mass Spectrometry and Density Functional Theory Characterizations of DNA Modifications  

E-Print Network [OSTI]

link yield from synthetic DNA harboring 5-X-pyrimidines,dU- and Br dC-containing synthetic DNA were reported, it wasthe phosphoramidites into synthetic DNA at a 5’-CpG-3’ site;

Williams, Renee Therese

2012-01-01T23:59:59.000Z

356

Ambient Sampling/Ionization Mass Spectrometry: Applications and Current Trends  

Science Journals Connector (OSTI)

drugs of abuse ... We felt that because ambient techniques are still young, fundamental studies are still critically needed to understand the range of applications that can be enabled by their use. ... The detection of counterfeit drugs is of particular interest since it is a growing issue in developing countries and over the Internet. ...

Glenn A. Harris; Asiri S. Galhena; Facundo M. Fernández

2011-04-15T23:59:59.000Z

357

Investigation of Metalloproteins Utilizing High Resolution Mass Spectrometry  

E-Print Network [OSTI]

.............................................................. 79 30 Fragment ion spectra of the [M+H]+ ions (a) Ac- Y(AEAAKA)2F-NH2 (-OCH3), (b) Ac-Y(AEAAKA)2F-NH2 (- 2OCH3) and (c) Ac-Y(AEAAKA)2F-NH2 (-3CH3)................. 82 31 Arrival time distribution (ATD) of the [M+H]+ ions of (a) Ac- Y...(AEAAKA)2F-NH2 (3OCH3) (FWHM:14), (b) Ac- Y(AEAAKA)2F-NH2 (2OCH3) (FWHM:25), (c) Ac- Y(AEAAKA)2F-NH2 (OCH3) (FWHM:21) and (d) Ac- Y(AEAAKA)2F-NH2 (FWHM:31)......................................... 85 32 Arrival time distribution (ATD) of the [M...

Wu, Zhaoxiang

2011-08-08T23:59:59.000Z

358

Environmental Mass Spectrometry: Emerging Contaminants and Current Issues  

Science Journals Connector (OSTI)

Alkylphenol ethoxylate surfactants are used heavily in the textile industry in pretreatment formulations and as additives in detergents or wetting agents for wool scouring, hydrogen peroxide bleaching, and dyeing. ...

Susan D. Richardson

2008-05-23T23:59:59.000Z

359

Extending the Capabilities of Single Particle Mass Spectrometry...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

nm creating a distinct sharp feature on the small particle side 11 of the vacuum aerodynamic size distribution. Thus, the two quantities needed to determine 12 particle...

360

Site-specific analysis of glycosylated proteins using mass spectrometry  

E-Print Network [OSTI]

principle of ion cyclotron resonance (ICR)……….12 1.2.3 Ion injection into ICR…………………………………………….14 1.2.4 Ion trapping in the ICR…………………………………………..16 1.2.5 Ions excitation and detection in FTICR………………………17 1.3 MS/MS experiments... tension of the liquid, the liquid droplet explodes into smaller droplets containing an excess of positive charges as shown in Figure 1-2. 15 Once the charged droplet is formed, evaporation of the solvent is attained through application of heated...

Irungu, Janet W.

2008-01-16T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Review of Mass Spectrometry–Based Metabolomics in Cancer Research  

Science Journals Connector (OSTI)

...potential future applications. Materials and Methods Identification...Administrative, technical, or material support (i.e., reporting...the studies reviewed: Pie diagrams including numbers and percentages...L-EDA in metabonomics data handling: Global metabolite profiling...

David B. Liesenfeld; Nina Habermann; Robert W. Owen; Augustin Scalbert; and Cornelia M. Ulrich

2013-12-01T23:59:59.000Z

362

Characterization of Bacteria by Particle Beam Mass Spectrometry  

Science Journals Connector (OSTI)

...of complex biological material is that of Meuzelaar...instrument, bulk samples of material (>10 Kg) are pyrolyzed...with minimal sample handling, from a naturally occurring...naires Disease (10). MATERIALS AND METHODS Bacteria...FIG. 1. Schematic diagram of particle beam MS...

Mahadeva P. Sinha; Robert M. Platz; Sheldon K. Friedlander; Vincent L. Vilker

1985-06-01T23:59:59.000Z

363

Mass Spectrometry and Density Functional Theory Characterizations of DNA Modifications  

E-Print Network [OSTI]

alkaline phosphatase (CIP). We chose Incorporation of DNADigestion NP1, exoPII, CIP, exoPI + Internal Standard Enzymethe addition of exoPI and CIP. Similar to NPI, exoPI creates

Williams, Renee Therese

2012-01-01T23:59:59.000Z

364

Alternate Methods of Sample Introduction for Plasma Mass Spectrometry  

Science Journals Connector (OSTI)

......usually operated at 27.1 MHz. Plasmas such as these were first...species from matrix elements, plasma gases, atmospheric gases, or a combination...is not as severe with an atmospheric pressure plasma. Although a majority of......

J.M. Carey; F.A. Byrdy; J.A. Caruso

1993-08-01T23:59:59.000Z

365

Plasma desorption mass spectrometry of organics at low temperatures  

E-Print Network [OSTI]

The desorption/ionization of volatile hydrocarbons by Plasma Desorption (PD) produces a series of molecular ions. Among these are deprotonated molecular ions, which are not usually observed in PD. The H-loss phenomenon was examined as a function...

Shirey, Eldon Lynn

1993-01-01T23:59:59.000Z

366

Defining the Role of Mass Spectrometry in Cancer Diagnostics  

Science Journals Connector (OSTI)

...concentration of individual proteins. Although automation of the standard practice of selective...research. This point has been driven home again and again in the past as promising...samples simultaneously, the development of automation via robotics has descended on the sample...

O. John Semmes

2004-10-01T23:59:59.000Z

367

Algorithms for tandem mass spectrometry-based proteomics  

E-Print Network [OSTI]

By restricting this advanced search to the set of unidenti?require time-consuming advanced search techniques. Insteadimplementation of the advanced database searches such as the

Frank, Ari Michael

2008-01-01T23:59:59.000Z

368

Quantitative analysis of amino acid mixtures by mass spectrometry  

E-Print Network [OSTI]

trii&is' ir, il f actor to a deer?a'e iri . ,eii iLivt ty. Tlic v ir i sl iors i;s ner~si? I ivity diirirss1 a rii:i c, in i&e corrcciccl I r-orss I l, c cnanr, cs in the ?ieights of t he I'itK pe, iks. l' rrsigt. r ? e arJc'? I that the I risrrumc...:. pool&lc:r;i. T:ie 1ix1 t of cl?i ceil. i osi wor? sio L iles & sii I ? I iy?u? tablish?i' in Ll, ? c irr?" L work. llew?ver s ciili, r L o, , ciir. ve - w?co lirieii; I, ir oi&illi Li, ? rii, ii. en coi. . i dere?. Ti ? sels. i Livit y 1 or eacs...

Bird, James Spencer

2012-06-07T23:59:59.000Z

369

Recovering Sparse Low-rank Blocks in Tandem Mass Spectrometry  

E-Print Network [OSTI]

, Pedro Navarro2, and Richard G. Baraniuk1 1 Rice University, Houston, TX, USA; e-mail: {studer, richb}@rice.edu 2 ETH Z¨urich, Z¨urich, Switzerland; e-mail: graemepope@gmail.com, navarro

370

Safeguards Verification Measurements using Laser Ablation, Absorbance Ratio Spectrometry in Gaseous Centrifuge Enrichment Plants  

SciTech Connect (OSTI)

Laser Ablation Absorbance Ratio Spectrometry (LAARS) is a new verification measurement technology under development at the US Department of Energy’s (DOE) Pacific Northwest National Laboratory (PNNL). LAARS uses three lasers to ablate and then measure the relative isotopic abundance of uranium compounds. An ablation laser is tightly focused on uranium-bearing solids producing a small plume containing uranium atoms. Two collinear wavelength-tuned spectrometry lasers transit through the plume and the absorbance of U-235 and U-238 isotopes are measured to determine U-235 enrichment. The measurement has high relative precision and detection limits approaching the femtogram range for uranium. It is independent of chemical form and degree of dilution with nuisance dust and other materials. High speed sample scanning and pinpoint characterization allow measurements on millions of particles/hour to detect and analyze the enrichment of trace uranium in samples. The spectrometer is assembled using commercially available components at comparatively low cost, and features a compact and low power design. Future designs can be engineered for reliable, autonomous deployment within an industrial plant environment. Two specific applications of the spectrometer are under development: 1) automated unattended aerosol sampling and analysis and 2) on-site small sample destructive assay measurement. The two applications propose game-changing technological advances in gaseous centrifuge enrichment plant (GCEP) safeguards verification. The aerosol measurement instrument, LAARS-environmental sampling (ES), collects aerosol particles from the plant environment in a purpose-built rotating drum impactor and then uses LAARS-ES to quickly scan the surface of the impactor to measure the enrichments of the captured particles. The current approach to plant misuse detection involves swipe sampling and offsite analysis. Though this approach is very robust it generally requires several months to obtain results from a given sample collection. The destructive assay instrument, LAARS-destructive assay (DA), uses a simple purpose-built fixture with a sampling planchet to collect adsorbed UF6 gas from a cylinder valve or from a process line tap or pigtail. A portable LAARS-DA instrument scans the microgram quantity of uranium collected on the planchet and the assay of the uranium is measured to ~0.15% relative precision. Currently, destructive assay samples for bias defect measurements are collected in small sample cylinders for offsite mass spectrometry measurement.

Anheier, Norman C.; Cannon, Bret D.; Qiao, Hong (Amy) [Amy; Phillips, Jon R.

2012-07-01T23:59:59.000Z

371

Accelerator Mass Spectrometric (AMS) Measurements of Plutonium Activity Concentrations and 240Pu/239Pu Atom Ratios In Soil Extracts Supplied by the Carlsbad Environmental Monitoring & Research Center  

SciTech Connect (OSTI)

Plutonium-239 ({sup 239}Pu) and plutonium-239+240 ({sup 239+240}Pu) activities concentrations and {sup 240}Pu/{sup 239}Pu atom ratios are reported for a series of chemically purified soil extracts received from the Carlsbad Environmental Monitoring & Research Center (CEMRC) in New Mexico. Samples were analyzed without further purification at the Lawrence Livermore National Laboratory (LLNL) using accelerator mass spectrometry (AMS). This report also includes a brief description of the AMS system and internal laboratory procedures used to ensure the quality and reliability of the measurement data.

Hamilton, T F; Brown, T A; Marchetti, A A; Martinelli, R E; Kehl, S R

2005-02-28T23:59:59.000Z

372

Determination of boron isotope ratios by Zeeman effect background correction-graphite furnace atomic absorption spectrometry  

Science Journals Connector (OSTI)

A new method for the determination of isotopic ratio of boron using Zeeman effect background correction-graphite furnace atomic absorption spectrometry with conventional atomizer and natural-boron hollow cathode source is described. The isotope-shift Zeeman effect at 208.9 nm is utilized for isotopic ratio determination. At a given concentration of total boron, the net absorbance decreases linearly with increasing 10B/11B ratio. The absorbances are recorded at the field strength of 1.0 T. The isotope ratios measured by the proposed method were in good agreement with the results obtained by inductively coupled plasma-quadruple mass spectrometry or thermal ionization mass spectrometry. The present method is fairly fast and less expensive compared to the above techniques and is quite suitable for plant environments.

S. Thangavel; S.V. Rao; K. Dash; J. Arunachalam

2006-01-01T23:59:59.000Z

373

Molecular Characterization of Biomass Burning Aerosols Using...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Biomass Burning Aerosols Using High Resolution Mass Spectrometry. Molecular Characterization of Biomass Burning Aerosols Using High Resolution Mass Spectrometry. Abstract: Chemical...

374

IRAQ'S WEAPONS OF MASS DESTRUCTION  

Science Journals Connector (OSTI)

DESPITE SEVEN YEARS OF INtrusive United Nations inspections and decimation of Iraq's weapons of mass destruction, Iraq was able to sequester sizable stocks of chemical and biological weapons, some missiles to deliver them, and the scientific and technical ...

LOIS EMBER

2002-09-16T23:59:59.000Z

375

Optical and Mass Spectrometric Studies of a Helium Dielectric-Barrier Atmospheric-Pressure Plasma Jet Used as an Ambient Desorption Ionization Source.  

E-Print Network [OSTI]

??Recently there has been a surge in the field of mass spectrometry centered around the concept of rapid analysis of target analytes with minimal or… (more)

Heywood, Matthew Spencer

2012-01-01T23:59:59.000Z

376

Fission product studies in the symmetric mass region  

SciTech Connect (OSTI)

Fission yields can be determined by radiochemical or mass spectrometric techniques. Mass spectrometry can provide more accurate data, particularly in the symmetric mass region where the probability of fission is low and uncertainties in isometric ratios occur. Fine structure in the mass distribution can usually only be determined by mass spectrometry. Many of the elements in the valley of symmetry have high ionization potentials and are therefore difficult to measure by solid source mass spectrometry. Analytical techniques have been developed to provide the sensitivity required to measure the small sample sizes available in fission product studies. Cumulative fission yields for ruthenium, palladium, cadmium, tin, and tellurium have been measured by mass spectrometry for the thermal and epicadmium fission of {sup 233}U and for thermal and epicadmium fission of {sup 239}Pu. These fission yields, which span the mass range 101 {le} A {le} 130, can be combined to give a mass yield curve for {sup 235}U in the valley region, which is symmetrical about A = 116.8 and exhibits fine structure in the mass 113 to 114 region. Fine structure in {sup 233}U is also present at mass 111. Mass spectrometric determinations of the fission yields of uranium ore at the Oklo mine site in Gabon enable the nuclear parameters of this natural reactor to be evaluated. This in turn enables the amounts of fission products produced in the reactor zone and the surrounding rocks enables an assessment to be made of the efficiency of this geological repository for containing radioactive waste. The elemental abundances can be determined by isotope dilution mass spectrometry. Unfortunately, the paucity of good fission yield data available for {sup 238}U by fast neutrons is a severe constraint in this evaluation.

De Laeter, J.R.; Rosman, K.J.R.; Loss, R.D. [Curtin Univ. of Technology, Perth (AU)

1993-05-01T23:59:59.000Z

377

Stable Isotope, Site-Specific Mass Tagging For Protein Identification  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Stable Isotope, Site-Specific Mass Tagging For Protein Stable Isotope, Site-Specific Mass Tagging For Protein Identification Stable Isotope, Site-Specific Mass Tagging For Protein Identification Proteolytic peptide mass mapping as measured by mass spectrometry provides an important method for the identification of proteins, which are usually identified by matching the measured and calculated m/z values of the proteolytic peptides. Available for thumbnail of Feynman Center (505) 665-9090 Email Stable Isotope, Site-Specific Mass Tagging For Protein Identification Proteolytic peptide mass mapping as measured by mass spectrometry provides an important method for the identification of proteins, which are usually identified by matching the measured and calculated m/z values of the proteolytic peptides. A unique identification is, however, heavily

378

Improving Alpha Spectrometry Energy Resolution by Ion Implantation with ICP-MS  

SciTech Connect (OSTI)

We report results of a novel technique using an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) as a method of source preparation for alpha spectrometry. This method produced thin, contaminant free 241Am samples which yielded extraordinary energy resolution which appear to be at the lower limit of the detection technology used in this research.

Dion, Michael P.; Liezers, Martin; Farmer, Orville T.; Miller, Brian W.; Morley, Shannon M.; Barinaga, Charles J.; Eiden, Gregory C.

2015-01-01T23:59:59.000Z

379

Cadmium measurements in coral skeleton using isotope dilutioninductively coupled plasmamass spectrometry  

E-Print Network [OSTI]

of pollution in corals growing near industri- al/urban sites where Cd concentrations can be 10 times higher­mass spectrometry Kathryn A. Matthews Department of Earth and Environmental Science, University of Pennsylvania, 240 skeleton to construct records of the frequency and intensity of oceanic upwelling. During upwelling

Mcdonough, William F.

380

High-Resolution Mass Spectroscopic Analysis of Secondary Organic Aerosol Generated by Ozonolysis of Isoprene  

SciTech Connect (OSTI)

The chemical composition of secondary organic aerosol (SOA) generated from the ozonolysis of isoprene (C5H8) in the presence of an OH scavenger was examined using high-resolution electrospray ionization mass spectrometry (ESI-MS). The chemical composition of SOA is complex, with more than 1000 assigned peaks observed in the positive and negative ion mode spectra. Only a small fraction of peaks corresponds to known products of isoprene oxidation, such as pyruvic acid, glycolic acid, methylglyoxal, etc. The absolute majority of the detected peaks correspond to highly oxidized oligomeric constituents of SOA, with an average O:C molar ratio of ~0.6. The corresponding organic mass (OM) to organic oxygen (OO) ratio is OM/OO?2.4. Approximately 8% of oxygen atoms in SOA are in the form of peroxides as quantified with an iodide test. Double bond equivalency (DBE) factors, representing the sum of all double bonds and rings, increase by 1 for every 2-3 additional carbon atoms in the molecule. The prevalent oligomer building blocks are therefore carbonyls or carboxylic acids with a C2-C3 skeleton. Kendrick analysis suggests that simple aldehydes, specifically formaldehyde, acetaldehyde, and methylglyoxal can serve as monomeric building blocks in the observed oligomers. The large number of reactive functional groups, especially organic peroxides and carbonyls, suggests that isoprene/O3 SOA should be prone to chemical and photochemical aging.

Nguyen, Tran B.; Bateman, Adam P.; Bones, David L.; Nizkorodov, Serguei; Laskin, Julia; Laskin, Alexander

2010-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Direct solid sample analysis with graphite furnace atomic absorption spectrometry—A fast and reliable screening procedure for the determination of inorganic arsenic in fish and seafood  

Science Journals Connector (OSTI)

Abstract Direct solid sample analysis with graphite furnace atomic absorption spectrometry (SS-GF AAS) was investigated initially with the intention of developing a method for the determination of total As in fish and other seafood. A mixture of 0.1% Pd+0.06% Mg+0.06% Triton X-100 was used as the chemical modifier, added in solution over the solid samples, making possible the use of pyrolysis and atomization temperatures of 1200 °C and 2400 °C, respectively. The sample mass had to be limited to 0.25 mg, as the integrated absorbance did not increase further with increasing sample mass. Nevertheless, the recovery of As from several certified reference materials was of the order of 50% lower than the certified value. Strong molecular absorption due to the phosphorus monoxide molecule (PO) was observed with high-resolution continuum source AAS (HR CS AAS), which, however, did not cause any spectral interference. A microwave-assisted digestion with HNO3/H2O2 was also investigated to solve the problem; however, the results obtained for several certified reference materials were statistically not different from those found with direct SS-GF AAS. Accurate values were obtained using inductively coupled plasma mass spectrometry (ICP-MS) to analyze the digested samples, which suggested that organic As compounds are responsible for the low recoveries. HPLC–ICP-MS was used to determine the arsenobetaine (AB) concentration. Accurate results that were not different from the certified values were obtained when the AB concentration was added to the As concentration found by SS-GF AAS for most certified reference materials (CRM) and samples, suggesting that SS-GF AAS could be used as a fast screening procedure for inorganic As determination in fish and seafood.

Ariane V. Zmozinski; Toni Llorente-Mirandes; Isabel C.F. Damin; José F. López-Sánchez; Maria Goreti R. Vale; Bernhard Welz; Márcia M. Silva

2015-01-01T23:59:59.000Z

382

Results from modeling and simulation of chemical downstream etch systems  

SciTech Connect (OSTI)

This report summarizes modeling work performed at Sandia in support of Chemical Downstream Etch (CDE) benchmark and tool development programs under a Cooperative Research and Development Agreement (CRADA) with SEMATECH. The Chemical Downstream Etch (CDE) Modeling Project supports SEMATECH Joint Development Projects (JDPs) with Matrix Integrated Systems, Applied Materials, and Astex Corporation in the development of new CDE reactors for wafer cleaning and stripping processes. These dry-etch reactors replace wet-etch steps in microelectronics fabrication, enabling compatibility with other process steps and reducing the use of hazardous chemicals. Models were developed at Sandia to simulate the gas flow, chemistry and transport in CDE reactors. These models address the essential components of the CDE system: a microwave source, a transport tube, a showerhead/gas inlet, and a downstream etch chamber. The models have been used in tandem to determine the evolution of reactive species throughout the system, and to make recommendations for process and tool optimization. A significant part of this task has been in the assembly of a reasonable set of chemical rate constants and species data necessary for successful use of the models. Often the kinetic parameters were uncertain or unknown. For this reason, a significant effort was placed on model validation to obtain industry confidence in the model predictions. Data for model validation were obtained from the Sandia Molecular Beam Mass Spectrometry (MBMS) experiments, from the literature, from the CDE Benchmark Project (also part of the Sandia/SEMATECH CRADA), and from the JDP partners. The validated models were used to evaluate process behavior as a function of microwave-source operating parameters, transport-tube geometry, system pressure, and downstream chamber geometry. In addition, quantitative correlations were developed between CDE tool performance and operation set points.

Meeks, E.; Vosen, S.R.; Shon, J.W.; Larson, R.S.; Fox, C.A.; Buchenauer

1996-05-01T23:59:59.000Z

383

CHEMICAL ENGINEERING Fall Term Spring Term  

E-Print Network [OSTI]

CHEG 332 Chemical Engineering Kinetics 3 CHEG 342 Heat and Mass Transfer 3 CHEG 341 Fluid Mechanics 3CHEMICAL ENGINEERING CURRICULUM Fall Term Spring Term EGGG 101 Introduction to Engineering (FYE) 2 CHEG 112 Introduction to Chemical Engineering 3 CHEM 111 General Chemistry 3 CHEM 112 General Chemistry

Lee, Kelvin H.

384

Ultra-high-resolution alpha spectrometry for nuclear forensics and safeguards applications  

SciTech Connect (OSTI)

We will present our work on the development of ultra-high-resolution detectors for alpha particle spectrometry. These detectors, based on superconducting transition-edge sensors, offer energy resolution that is five to ten times better than conventional silicon detectors. Using these microcalorimeter detectors, the isotopic composition of mixed-actinide samples can be determined rapidly without the need for actinide separation chemistry to isolate each element, or mass spectrometry to separate isotopic signatures that can not be resolved using traditional alpha spectrometry (e.g. Pu-239/Pu-240, or Pu-238/Am-241). This paper will cover the detector and measurement system, actinide source preparation, and the quantitative isotopic analysis of a number of forensics- and safeguards-relevant radioactive sources.

Bacrania, Minesh K [Los Alamos National Laboratory; Croce, Mark [Los Alamos National Laboratory; Bond, Evelyn [Los Alamos National Laboratory; Dry, Donald [Los Alamos National Laboratory; Moody, W. Allen [Los Alamos National Laboratory; Lamont, Stephen [Los Alamos National Laboratory; Rabin, Michael [Los Alamos National Laboratory; Rim, Jung [Los Alamos National Laboratory; Smith, Audrey [Los Alamos National Laboratory; Beall, James [NIST-BOULDER; Bennett, Douglas [NIST-BOULDER; Kotsubo, Vincent [NIST-BOULDER; Horansky, Robert [NIST-BOULDER; Hilton, Gene [NIST-BOULDER; Schmidt, Daniel [NIST-BOULDER; Ullom, Joel [NIST-BOULDER; Cantor, Robin [STAR CRYOELECTRONICS

2010-01-01T23:59:59.000Z

385

In situ chemical imaging at the sub-biofilm-scale | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

scientists working at EMSL used time-of-flight secondary ion mass spectrometry, or ToF-SIMS, under high vacuum conditions, coupled with a vacuum-compatible liquid probe, to...

386

Micromachined chemical jet dispenser  

DOE Patents [OSTI]

A dispenser for chemical fluid samples that need to be precisely ejected in size, location, and time. The dispenser is a micro-electro-mechanical systems (MEMS) device fabricated in a bonded silicon wafer and a substrate, such as glass or silicon, using integrated circuit-like fabrication technology which is amenable to mass production. The dispensing is actuated by ultrasonic transducers that efficiently produce a pressure wave in capillaries that contain the chemicals. The 10-200 .mu.m diameter capillaries can be arranged to focus in one spot or may be arranged in a larger dense linear array (.about.200 capillaries). The dispenser is analogous to some ink jet print heads for computer printers but the fluid is not heated, thus not damaging certain samples. Major applications are in biological sample handling and in analytical chemical procedures such as environmental sample analysis, medical lab analysis, or molecular biology chemistry experiments.

Swierkowski, Steve P. (Livermore, CA)

1999-03-02T23:59:59.000Z

387

CHEMICAL MARKETING  

Science Journals Connector (OSTI)

CHEMICAL MARKETING ... The reason, I believe, is that the chemical industry has been blind (until very recently) to the need for paying attention to marketing. ... Its marketing needs are now like those of a mature—no longer a growing—industry. ...

1960-12-19T23:59:59.000Z

388

Screening masses in thermal and dense medium  

E-Print Network [OSTI]

Screening masses of different hadronic states are studied in thermal and dense medium on lattice. It has been found that screening masses increase with the temperature. In deconfinement phase, chemical potential enhances the screening masses. We use the normalization with respect to lowest Matsubara frequency to characterize dissolving of hadronic bound states at high temperatures. It has been found that different hadronic states have different dissolving temperatures and their survivals are considerably improved at finite chemical potentials.

A. Tawfik

2006-05-29T23:59:59.000Z

389

Human Plasma Proteome Analysis by Multidimensional Chromatography Prefractionation and Linear Ion Trap Mass  

E-Print Network [OSTI]

to facilitate human plasma proteome research. Keywords: proteomics · human plasma · mass spectrometry · two the past decades of plasma proteome research works based on 2-DE:2,14-20 the highest quantity of identified

Tian, Weidong

390

Matrixassisted laser desorption/ionization mass spectrometric analysis of aliphatic biodegradable photoluminescent polymers  

E-Print Network [OSTI]

established that the new ILMs provided good spottospot reproducibility and high ionization efficiency compared/ionization mass spectrometry (MALDIMS). The polymers, formed by a condensation reaction of three components

Yang, Jian

391

RAPID COMMUNICATIONS IN MASS SPECTROMETRY Rapid Commun. Mass Spectrom. 2004; 18: 27062712  

E-Print Network [OSTI]

techniques to generate gas-phase ions from samples in condensed phases which have revolutionized collision gas into a cell located on the ion flight path. Introduction of collision gas into an analyzer

Kim, Myung Soo

392

RAPID COMMUNICATIONS IN MASS SPECTROMETRY Rapid Commun. Mass Spectrom. 2005; 19: 25282538  

E-Print Network [OSTI]

the collision-induced decomposition spectra of ammoniated triglycerides as a function of fatty acid chain length of the collision-induced decomposition (CID) products of ammoniated TAGs (ammonium ion adducts) were examined corresponding to loss of that fatty acid. Mechanisms of the formation and decomposition of ammoniated TAGs

Evans, Jason

393

Bio-mass for biomass: biological mass spectrometry techniques for biomass fast pyrolysis oils.  

E-Print Network [OSTI]

??Biomass fast pyrolysis oils, or bio-oils, are a promising renewable energy source to supplement or replace petroleum-based products and fuels. However, there is a current… (more)

Dalluge, Erica A.

2013-01-01T23:59:59.000Z

394

Solvent Extraction of Chemical Attribution Signature Compounds from Painted Wall Board: Final Report  

SciTech Connect (OSTI)

This report summarizes work that developed a robust solvent extraction procedure for recovery of chemical attribution signature (CAS) compound dimethyl methyl phosphonate (DMMP) (as well as diethyl methyl phosphonate (DEMP), diethyl methyl phosphonothioate (DEMPT), and diisopropyl methyl phosphonate (DIMP)) from painted wall board (PWB), which was selected previously as the exposed media by the chemical attribution scientific working group (CASWG). An accelerated solvent extraction approach was examined to determine the most effective method of extraction from PWB. Three different solvent systems were examined, which varied in solvent strength and polarity (i.e., 1:1 dichloromethane : acetone,100% methanol, and 1% isopropanol in pentane) with a 1:1 methylene chloride : acetone mixture having the most robust and consistent extraction for four original target organophosphorus compounds. The optimum extraction solvent was determined based on the extraction efficiency of the target analytes from spiked painted wallboard as determined by gas chromatography x gas chromatography mass spectrometry (GCxGC-MS) analysis of the extract. An average extraction efficiency of approximately 60% was obtained for these four compounds. The extraction approach was further demonstrated by extracting and detecting the chemical impurities present in neat DMMP that was vapor-deposited onto painted wallboard tickets.

Wahl, Jon H.; Colburn, Heather A.

2009-10-29T23:59:59.000Z

395

Extending Penning trap mass measurements with SHIPTRAP to the heaviest elements  

SciTech Connect (OSTI)

Penning-trap mass spectrometry of radionuclides provides accurate mass values and absolute binding energies. Such mass measurements are sensitive indicators of the nuclear structure evolution far away from stability. Recently, direct mass measurements have been extended to the heavy elements nobelium (Z=102) and lawrencium (Z=103) with the Penning-trap mass spectrometer SHIPTRAP. The results probe nuclear shell effects at N=152. New developments will pave the way to access even heavier nuclides.

Block, M.; Ackermann, D.; Herfurth, F.; Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Blaum, K. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg, Germany and Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Droese, C.; Marx, G.; Schweikhard, L. [Ernst-Moritz-Arndt-Universitaet, 17487 Greifswald (Germany); Duellmann, Ch. E. [Johannes Gutenberg-Universitaet, 55099 Mainz, Germany and GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt, Germany and Helmholtz-Institut Mainz, 55099 Mainz (Germany); Eibach, M. [Ruprecht-Karls-Universitaet, 69120 Heidelberg, Germany and Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Eliseev, S. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Haettner, E.; Plass, W. R.; Scheidenberger, C. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt, Germany and Justus-Liebig-Universitaet, 35392 Giessen (Germany); Hessberger, F. P. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt, Germany and Helmholtz-Institut Mainz, 55099 Mainz (Germany); Ramirez, E. Minaya [Helmholtz-Institut Mainz, 55099 Mainz, Germany and GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Nesterenko, D. [Petersburg Nuclear Physics Institute, Gatchina, 188300 St. Petersburg (Russian Federation); and others

2013-03-19T23:59:59.000Z

396

The mass  

Science Journals Connector (OSTI)

The mass of the charged Higgs boson at the 1-loop level is investigated, assuming the CP symmetry to be violated explicitly in the Higgs sector of the minimal supersymmetric standard model (MSSM). It is found that there is a parameter region of the MSSM where the presence of explicit CP violation in the Higgs sector yields negative radiative corrections to the charged Higgs boson mass. Thus, the charged Higgs boson in the MSSM may have as low a mass as 60 GeV at the 1-loop level, if the CP symmetry is violated. This lower bound may be improved by the Higgs search at LEP2, which imposes experimental constraints on the charged Higgs mass, as well as on the masses of the neutral Higgs bosons. Hence, LEP2 can constrain experimentally the charged Higgs mass to be not smaller than 109 GeV under our assumption. In addition, it sets 75 GeV as the lower bound on the mass of the lightest neutral Higgs boson, and 84 GeV for that of the next-to-lightest neutral Higgs boson.

Seung Woo Ham; Sun Kun Oh; Eun Jong Yoo; Hyun Kyu Lee

2001-01-01T23:59:59.000Z

397

Retrieval of DNA using soft-landing after mass analysis by ESI-FTICR for enzymatic manipulation  

SciTech Connect (OSTI)

The DNA modifications that lead to mutations are of direct interest for, e.g. the understanding of DNA damage recognition and repair. The characterization of the modified oligonucleotides and enzymatic responses to specific DNA modifications are of primary concern, but also present major analytical challenges. Among the available techniques, mass spectrometry has become an increasingly important tool for the study of oligonucleotides, their mutations, and interactions. Conventionally, mass spectrometry provides mass and structural information (e.g. from dissociation experiments and the use of tandem mass spectrometry). However, the small quantities of material analyzed and the destructive nature of conventional mass spectrometric detection (e.g., due to high energy impact on particle multiplier surfaces) have precluded subsequent use of mass separated biopolymers. The authors report the use of mass spectrometry in conjunction with soft-landing for the high-resolution analysis, separation, and selective collection of oligonucleotides, and their subsequent retrieval for enzymatic manipulation. Fourier transform ion cyclotron resonance mass spectrometry coupled with electrospray ionization (ESI-FTICR) allows nondestructive (i.e., image current) measurement of the mass-to-charge ratios (m/z) of ions with high sensitivity, resolution, and mass accuracy.

Feng, B.; Wunschel, D.S.; Masselon, C.D.; Pasa-Tolic, L.; Smith, R.D.

1999-09-29T23:59:59.000Z

398

Chemical Occurrences  

Broader source: Energy.gov [DOE]

Classification of Chemical Occurrence Reports into the following four classes: Occurrences characterized by serious energy release, injury or exposure requiring medical treatment, or severe environmental damage, Occurrences characterized by minor injury or exposure, or reportable environmental release, Occurrences that were near misses including notable safety violations and Minor occurrences.

399

Subscriber access provided by Caltech Library Services The Journal of Physical Chemistry A is published by the American Chemical  

E-Print Network [OSTI]

Laboratory, Richland, WA, and Interfacial Chemistry Group, Idaho National Laboratory, Idaho Falls, ID Recei (ESI) and studied by tandem ion-trap mass spectrometry to determine the general effect of ligand charge

Goddard III, William A.

400

Automated workflows for accurate mass-based putative metabolite identification in LC/MS-derived metabolomic datasets  

Science Journals Connector (OSTI)

......MS-derived metabolomic datasets Marie Brown 1 David C. Wedge...signals present in complex datasets. Results: Three workflows...LC-MS-derived metabolomic datasets. The collection of workflows...Mass spectrometry (MS) and nuclear magnetic resonance spectroscopy......

Marie Brown; David C. Wedge; Royston Goodacre; Douglas B. Kell; Philip N. Baker; Louise C. Kenny; Mamas A. Mamas; Ludwig Neyses; Warwick B. Dunn

2011-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Modeling the Mass Transfer of Hydrophobic Organic Pollutants in Briefly and Continuously Mixed Sediment after Amendment with Activated Carbon  

Science Journals Connector (OSTI)

Sarah E. Hale and David Werner * ... PAHs were quantified by gas chromatography mass spectrometry and details of these methods can be found in SI pages S3 and S7, respectively. ...

Sarah E. Hale; David Werner

2010-04-14T23:59:59.000Z

402

Mass Spectrometer: Orbitrap | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

productivity over vast regions of the oceans. We... Separation and Classification of Lipids Using Differential Ion Mobility Spectrometry. Correlations between the dimensions...

403

Chemical & Biomolecular Engineering Undergraduate Curriculum First Semester  

E-Print Network [OSTI]

Name Hours CHEM 113 Fundamental Chemistry I 1 4 CHME 113 Intro to Chemical Engineering I 2 ENGR 010 Quantitative Chemistry Lab 1 2 CHME 114 Intro to Chemical Engineering II 2 MATH 107 Analytic Geometry Chemistry Lab 1 CHME 202 Mass & Energy Balances 3 ENGM 223 Engineering Statics 3 ENGR 020 Sophomore

Farritor, Shane

404

Chemical Speciation of Sulfur in Marine Cloud Droplets and Particles: Analysis of Individual Particles from Marine Boundary Layer over the California Current  

SciTech Connect (OSTI)

Detailed chemical speciation of the dry residue particles from individual cloud droplets and interstitial aerosol collected during the Marine Stratus Experiment (MASE) was performed using a combination of complementary microanalysis techniques. Techniques include computer controlled scanning electron microscopy with energy dispersed analysis of X-rays (CCSEM/EDX), time-of-flight secondary ionization mass spectrometry (TOF-SIMS), and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Samples were collected at the ground site located in Point Reyes National Seashore, approximately 1 km from the coast. This manuscript focuses on the analysis of individual particles sampled from air masses that originated over the open ocean and then passed through the area of the California current located along the northern California coast. Based on composition, morphology, and chemical bonding information, two externally mixed, distinct classes of sulfur containing particles were identified: chemically modified (aged) sea salt particles and secondary formed sulfate particles. The results indicate substantial heterogeneous replacement of chloride by methanesulfonate (CH3SO3-) and non-sea salt sulfate (nss-SO42-) in sea-salt particles with characteristic ratios of nss-S/Na>0.10 and CH3SO3-/nss-SO42->0.6.

William R. Wiley Environmental Sciences Laboratory, Pacific Northwest National Laboratory; Gilles, Mary K; Hopkins, Rebecca J.; Desyaterik, Yury; Tivanski, Alexei V.; Zaveri, Rahul A.; Berkowitz, Carl M.; Tyliszczak, Tolek; Gilles, Mary K.; Laskin, Alexander

2008-03-12T23:59:59.000Z

405

The molecular structure of PrI3 and GdI3 as determined by synchronous gas-phase electron diffraction and mass spectrometric experiment assisted by quantum chemical calculations  

Science Journals Connector (OSTI)

A gas electron diffraction study of PrI3 and GdI3 has been carried out in combination with mass spectrometric vapour monitoring at 1110(10) K and 1100(10) K, respectively. Up to 3 mol.% of dimeric species was obs...

Nina I. Giricheva; Sergey A. Shlykov; Elena A. Lapykina…

2011-04-01T23:59:59.000Z

406

Chemical Accelerators The phrase "chemical accelerators"  

E-Print Network [OSTI]

Meetings Chemical Accelerators The phrase "chemical accelerators" is scarcely older than for one or two dozen people grew to include nearly a hundred. Chemical accelerators is a name sug- gested-volt region. Thus chemical accelerators can provide the same type of information for elemen- tary chemical

Zare, Richard N.

407

Bio-oil Analysis Using Negative Electrospray Ionization: Comparative Study of High-Resolution Mass Spectrometers and Phenolic versus Sugaric Components  

SciTech Connect (OSTI)

We have previously demonstrated that a petroleomic analysis could be performed for bio-oils and revealed the complex nature of bio-oils for the nonvolatile phenolic compounds (Smith, E.; Lee, Y. J. Energy Fuels 2010, 24, 5190?5198). As a subsequent study, we have adapted electrospray ionization in negative-ion mode to characterize a wide variety of bio-oil compounds. A comparative study of three common high-resolution mass spectrometers was performed to validate the methodology and to investigate the differences in mass discrimination and resolution. The mass spectrum is dominated by low mass compounds with m/z of 100–250, with some compounds being analyzable by gas chromatography–mass spectrometry (GC–MS). We could characterize over 800 chemical compositions, with only about 40 of them being previously known in GC–MS. This unveiled a much more complex nature of bio-oils than typically shown by GC–MS. The pyrolysis products of cellulose and hemicellulose, particularly polyhydroxy cyclic hydrocarbons (or what we call “sugaric” compounds), such as levoglucosan, could be effectively characterized with this approach. Phenolic compounds from lignin pyrolysis could be clearly distinguished in a contour map of double bond equivalent (DBE) versus the number of carbons from these sugaric compounds.

Smith, Erica A.; Park, Soojin; Klein, Adam T.; Lee, Young Jin

2012-05-16T23:59:59.000Z

408

Isolation and Recovery of 2-Aminoethanol, N-Methyl-2-Aminoethanol, and N,N-Dimethyl-2-Aminoethanol from a Copper Amine Aqueous Matrix and from Amine-Treated Sawdust Using Liquid—Liquid Extraction and Liquid—Solid Extraction Combined with Capillary Gas Chromatography—Ion-Trap Mass Spectrometry  

Science Journals Connector (OSTI)

......LLE of the spiked water and aqueous copper...resulted from loss of a water molecule and the...ence of oxygen, nitrogen, and carbon dioxide...impurities in our carrier gas. Given this mass...AE dissolved in water, the following base...Polarity Density* Solubility in water Solvent......

Paul R. Loconto; Yanlyang Pan; Donatien-Pa Kamdem

1998-06-01T23:59:59.000Z

409

Gas-phase chemical reactions of transition metal clusters with simple molecules  

SciTech Connect (OSTI)

Chemical reactions of isolated transition metal clusters are studied in a laser-vaporization cluster source coupled to a continuous-flow reactor. Detection of reaction products is via laser ionization and time-of-flight mass spectrometry. Experimental probes that have been developed include: (1) kinetics measurements, in which the disappearance of bare cluster signal with increasing reagent gas flow is used to determine absolute reaction rate constants for the addition of the first adsorbate molecule; (2) product composition measurements, in which inferences as to cluster structure and the nature of surface binding sites are derived by determining the total number of adsorbates the clusters can accommodate; (3) laser-induced desorption experiments, from which adsorbate binding energies can be derived; and (4) the observation of actual chemical reactions on cluster surfaces, such as hydrogen/deuterium exchange or adsorbate photochemistry. In addition, a new experimental procedure has been developed that, in a single series of measurements, provides measures of the first three parameters listed above. A review is given of earlier studies of the reaction of iron clusters with hydrogen. More recent results on the reaction of iron clusters with ammonia, and the reaction of ammoniated iron clusters with hydrogen, are also presented.

Riley, S.J.; Parks, E.K.

1986-01-01T23:59:59.000Z

410

The effect of storage on the chemical composition and thermochemical conversion of biomass  

SciTech Connect (OSTI)

The effects of storage on different biomass feedstocks, including short rotation woody crops, herbaceous crops, and agricultural residues have been studied. Results of the analysis of fresh and stored material from four short rotation woody species using traditional wet chemical analysis showed differences in the chemical composition of the feedstocks harvested at different times. Changes that occurred in the material after unprotected storage outside for 26 weeks were measured. Over the period of the storage study, small changes were observed in the structural cell wall components including cellulose, hemicellulose and lignin. Larger changes were observed in the materials that could be extracted with 95% ethanol. Also presented are results from a rapid analytical technique using pyrolysis-mass spectrometry combined with multivariate statistical analysis to assess the influence of storage on the composition and thermochemical conversion of the different biomass feedstocks. Because of the rapid nature of this technique, a large number of samples could be screened to determine the extent of degradation throughout the piles. Application of this technique to the samples in this study indicated that, for the most part, significant changes did not occur in the composition of biomass taken from the centers of the piles. However, significant changes were detected in biomass taken from the outer layers and isolated regions in the piles where most advanced degradation had occurred.

Davis, M.F.; Agblevor, F.A.; Johnson, D.K. [National Renewable Energy Lab., Golden, CO (United States)] [and others

1994-12-31T23:59:59.000Z

411

Chemical Science  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Chemical Science Chemical Science Compton double ionization of helium in the region of the cross-section maximum B. Krässig, R.W. Dunford, D.S. Gemmell, S. Hasegawa, E.P. Kanter, H. Schmidt-Böcking, W. Schmitt, S.H. Southworth, Th. Weber, and L. Young Crystal structure analysis of microporous Na16Nb12.8Ti3.2O44.8(OH)3.2l8H2O and Na/Nb/Zr/O/H2O phases A. Tripathi, J. Parise, M. Nyman, T.M. Nenoff, and W. Harrison Double K-photoionization of heavy atoms R.W. Dunford, D.S. Gemmell, E.P. Kanter, B. Krässig, and S.H. Southworth Forward-backward asymmetries of atomic photoelectrons S.H. Southworth, B. Krässig, E.P. Kanter, J.C. Bilheux, R.W. Dunford, D.S. Gemmell, S. Hasegawa, and L. Young In situreduction of various iron oxides to form high-surface-area Fe-metal catalysts as studied by high-resolution powder diffraction

412

GOMA 6.0 : a full-Newton finite element program for free and moving boundary problems with coupled fluid/solid momentum, energy, mass, and chemical species transport : user%3CU%2B2019%3Es guide.  

SciTech Connect (OSTI)

Goma 6.0 is a finite element program which excels in analyses of multiphysical processes, particularly those involving the major branches of mechanics (viz. fluid/solid mechanics, energy transport and chemical species transport). Goma is based on a full-Newton-coupled algorithm which allows for simultaneous solution of the governing principles, making the code ideally suited for problems involving closely coupled bulk mechanics and interfacial phenomena. Example applications include, but are not limited to, coating and polymer processing flows, super-alloy processing, welding/soldering, electrochemical processes, and solid-network or solution film drying. This document serves as a user's guide and reference.

Schunk, Peter Randall; Rao, Rekha Ranjana; Chen, Ken Shuang; Labreche, Duane A.; Sun, Amy Cha-Tien; Hopkins, Matthew Morgan; Moffat, Harry K.; Roach, Robert Allen; Hopkins, Polly L.; Notz, Patrick K.; Roberts, Scott Alan; Sackinger, Philip A.; Subia, Samuel Ramirez; Wilkes, Edward Dean; Baer, Thomas A.; Noble, David R.; Secor, Robert B. [3M Engineering Systems and Technology, St. Paul, MN] [3M Engineering Systems and Technology, St. Paul, MN

2013-07-01T23:59:59.000Z

413

Chemical vapor deposition sciences  

SciTech Connect (OSTI)

Chemical vapor deposition (CVD) is a widely used method for depositing thin films of a variety of materials. Applications of CVD range from the fabrication of microelectronic devices to the deposition of protective coatings. New CVD processes are increasingly complex, with stringent requirements that make it more difficult to commercialize them in a timely fashion. However, a clear understanding of the fundamental science underlying a CVD process, as expressed through computer models, can substantially shorten the time required for reactor and process development. Research scientists at Sandia use a wide range of experimental and theoretical techniques for investigating the science of CVD. Experimental tools include optical probes for gas-phase and surface processes, a range of surface analytic techniques, molecular beam methods for gas/surface kinetics, flow visualization techniques and state-of-the-art crystal growth reactors. The theoretical strategy uses a structured approach to describe the coupled gas-phase and gas-surface chemistry, fluid dynamics, heat and mass transfer of a CVD process. The software used to describe chemical reaction mechanisms is easily adapted to codes that model a variety of reactor geometries. Carefully chosen experiments provide critical information on the chemical species, gas temperatures and flows that are necessary for model development and validation. This brochure provides basic information on Sandia`s capabilities in the physical and chemical sciences of CVD and related materials processing technologies. It contains a brief description of the major scientific and technical capabilities of the CVD staff and facilities, and a brief discussion of the approach that the staff uses to advance the scientific understanding of CVD processes.

NONE

1992-12-31T23:59:59.000Z

414

Searching for the Solar System's Chemical Recipe  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Searching for the Solar System's Searching for the Solar System's Chemical Recipe Searching for the Solar System's Chemical Recipe Print Wednesday, 20 February 2013 00:00 The ratio of isotopes in elements like oxygen, sulfur, and nitrogen were once thought to be much the same everywhere, determined only by their different masses. Then isotope ratios in meteorites, interplanetary dust and gas, and the sun itself were found to differ from those on Earth. Planetary researchers like UC San Diego's Mark Thiemens and his colleagues, working with Musa Ahmed of the Chemical Sciences Division, are now using the Chemical Dynamics Beamline at the Advanced Light Source to study these "mass-independent" effects and their origins in the chemical processes of the early solar system.

415

Plasma Mass Filters For Nuclear Waste Reprocessing  

SciTech Connect (OSTI)

Practical disposal of nuclear waste requires high-throughput separation techniques. The most dangerous part of nuclear waste is the fission product, which contains the most active and mobile radioisotopes and produces most of the heat. We suggest that the fission products could be separated as a group from nuclear waste using plasma mass filters. Plasmabased processes are well suited to separating nuclear waste, because mass rather than chemical properties are used for separation. A single plasma stage can replace several stages of chemical separation, producing separate streams of bulk elements, fission products, and actinoids. The plasma mass filters may have lower cost and produce less auxiliary waste than chemical processing plants. Three rotating plasma configurations are considered that act as mass filters: the plasma centrifuge, the Ohkawa filter, and the asymmetric centrifugal trap.

Abraham J. Fetterman and Nathaniel J. Fisch

2011-05-26T23:59:59.000Z

416

Mass Transport within Soils  

SciTech Connect (OSTI)

Contaminants in soil can impact human health and the environment through a complex web of interactions. Soils exist where the atmosphere, hydrosphere, geosphere, and biosphere converge. Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative proportions of these components determine the value of the soil for agricultural and for other human uses. These proportions also determine, to a large extent, how a substance added to soil is transported and/or transformed within the soil (Spositio, 2004). In mass-balance models, soil compartments play a major role, functioning both as reservoirs and as the principal media for transport among air, vegetation, surface water, deeper soil, and ground water (Mackay, 2001). Quantifying the mass transport of chemicals within soil and between soil and atmosphere is important for understanding the role soil plays in controlling fate, transport, and exposure to multimedia pollutants. Soils are characteristically heterogeneous. A trench dug into soil typically reveals several horizontal layers having different colors and textures. As illustrated in Figure 1, these multiple layers are often divided into three major horizons: (1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, lies below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. Below these three horizons lies the saturated zone - a zone that encompasses the area below ground surface in which all interconnected openings within the geologic media are completely filled with water. Similarly to the unsaturated zone with three major horizons, the saturated zone can be further divided into other zones based on hydraulic and geologic conditions. Wetland soils are a special and important class in which near-saturation conditions exist most of the time. When a contaminant is added to or formed in a soil column, there are several mechanisms by which it can be dispersed, transported out of the soil column to other parts of the environment, destroyed, or transformed into some other species. Thus, to evaluate or manage any contaminant introduced to the soil column, one must determine whether and how that substance will (1) remain or accumulate within the soil column, (2) be transported by dispersion or advection within the soil column, (3) be physically, chemically, or biologically transformed within the soil (i.e., by hydrolysis, oxidation, etc.), or (4) be transported out of the soil column to another part of the environment through a cross-media transfer (i.e., volatilization, runoff, ground water infiltration, etc.). These competing processes impact the fate of physical, chemical, or biological contaminants found in soils. In order to capture these mechanisms in mass transfer models, we must develop mass-transfer coefficients (MTCs) specific to soil layers. That is the goal of this chapter. The reader is referred to other chapters in this Handbook that address related transport processes, namely Chapter 13 on bioturbation, Chapter 15 on transport in near-surface geological formations, and Chapter 17 on soil resuspention. This chapter addresses the following issues: the nature of soil pollution, composition of soil, transport processes and transport parameters in soil, transformation processes in soil, mass-balance models, and MTCs in soils. We show that to address vertical heterogeneity in soils in is necessary to define a characteristic scaling depth and use this to establish process-based expressions for soil MTCs. The scaling depth in soil and the corresponding MTCs depend strongly on (1) the composition of the soil and physical state of the soil, (2) the chemical and physic

McKone, Thomas E.

2009-03-01T23:59:59.000Z

417

Mass and Lifetime Measurements in Storage Rings  

SciTech Connect (OSTI)

Masses of nuclides covering a large area of the chart of nuclides can be measured in storage rings where many ions circulate at the same time. In this paper the recent progress in the analysis of Schottky mass spectrometry data is presented as well as the technical improvements leading to higher accuracy for isochronous mass measurements with a time-of-flight detector. The high sensitivity of the Schottky method down to single ions allows to measure lifetimes of nuclides by observing mother and daughter nucleus simultaneously. In this way we investigated the decay of bare and H-like 140Pr. As we could show the lifetime can be even shortened compared to those of atomic nuclei despite of a lower number of electrons available for internal conversion or electron capture.All these techniques will be implemented with further improvements at the storage rings of the new FAIR facility at GSI in the future.

Weick, H.; Beckert, K.; Beller, P.; Bosch, F.; Dimopoulou, C.; Kozhuharov, C.; Kurcewicz, J.; Mazzocco, M.; Nociforo, C.; Nolden, F.; Steck, M.; Sun, B.; Winkler, M. [Gesellschaft fuer Schwerionenforschung mbH, 64291 Darmstadt (Germany); Brandau, C.; Chen, L.; Geissel, H.; Knoebel, R.; Litvinov, S. A.; Litvinov, Yu. A.; Scheidenberger, C. [Gesellschaft fuer Schwerionenforschung mbH, 64291 Darmstadt (Germany); II. Phys. Institut, Justus-Liebig-Universitaet Giessen, 35392 Giessen (Germany)] (and others)

2007-05-22T23:59:59.000Z

418

Mass-Independent Isotope Effects  

Science Journals Connector (OSTI)

Scientific interests: ESR and NMR spectroscopies, molecular magnets, mechanisms of chemical and biochemical reactions, spin physics and chemistry, isotopes and isotope effects in chemistry and biochemistry. ... Another mass-independent isotope effect was detected in 1983 as a deviation of isotopic distribution in reaction products from that which would be expected from the mass-dependent isotope effect. ... Later, Nomura et al.(92) have found isotopic 233U anomaly in the U4+–U6+ exchange reaction; they noted that the isotope effect was correlated with isotope shifts in the atomic spectra of uranium isotopes. ...

Anatoly L. Buchachenko

2013-01-09T23:59:59.000Z

419

Heavy ion Rutherford Backscattering Spectrometry (HIRBS) for the near surface characterization of electronic materials  

SciTech Connect (OSTI)

The use of heavy ion projectiles for Rutherford Backscattering Spectrometry (RBS) provides several potential advantages over conventional RBS with /sup 4/He beams. Among these advantages are the improved mass resolution for heavy elements (>50 amu) and the increased accessible depth of analysis. A series of experiments using 20-MeV /sup 16/O beam backscattered from a variety of targets was performed in order to examine the potential advantages of heavy ion RBS in the near-surface characterization of semiconductors with masses >50 amu. Important questions such as mass resolution, depth resolution, isotopic effects, absolute sensitivity and minimum detectable limit of impurities were investigated. Ion implantations and multiple layered structures on GaAs substrates as well as metal germanide systems were studied. The development of the method in conjunction with the channeling technique is also discussed.

Yu, K.M.

1984-12-01T23:59:59.000Z

420

Selection and generation of waveforms for differential mobility spectrometry  

SciTech Connect (OSTI)

Devices based on differential mobility spectrometry (DMS) are used in a number of ways, including applications as ion prefilters for API-MS systems, as detectors or selectors in hybrid instruments (GC-DMS, DMS-IMS), and in standalone systems for chemical detection and identification. DMS ion separation is based on the relative difference between high field and low field ion mobility known as the alpha dependence, and requires the application of an intense asymmetric electric field known as the DMS separation field, typically in the megahertz frequency range. DMS performance depends on the waveform and on the magnitude of this separation field. In this paper, we analyze the relationship between separation waveform and DMS resolution and consider feasible separation field generators. We examine ideal and practical DMS separation field waveforms and discuss separation field generator circuit types and their implementations. To facilitate optimization of the generator designs, we present a set of relations that connect ion alpha dependence to DMS separation fields. Using these relationships we evaluate the DMS separation power of common generator types as a function of their waveform parameters. Optimal waveforms for the major types of DMS separation generators are determined for ions with various alpha dependences. These calculations are validated by comparison with experimental data.

Krylov, Evgeny V.; Coy, Stephen L.; Nazarov, Erkinjon G. [Sionex Corporation, 8-A Preston Ct., Bedford, Massachusetts 01730 (United States); Vandermey, John; Schneider, Bradley B.; Covey, Thomas R. [MDS Analytical Technologies, 71 Four Valley Drive, Concord, Ontario L4K 4V8 (Canada)

2010-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Argonne Chemical Sciences & Engineering - Fundamental Interactions -  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

potential energy surface potential energy surface A potential energy surface for the reaction of CH and N2. comparison of experimental data Comparison of experimental and theoretical rate data for the reaction of OH and C3H8. Chemical Kinetics An accurate computational model for combustion will require a knowledge of the rates of all relevant chemical reactions over a large range of temperature and pressure. The goal of this subtask is to provide the necessary rates through a combination of direct experimental measurement and theoretical modeling. The experimental component of this subtask involves a combination of complementary techniques based on the use of shock tubes and flow tubes, along with a variety of detection methods, including atomic resonance absorption spectrometry, electronic absorption

422

E-Print Network 3.0 - absorption spectrometry configurations...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Trace Elements in Biological Tissues by Summary: Block Digestion and Spike-Height Flame Atomic Absorption Spectrometry ,.. U. TINGGI AND W. MAHER School... absorption...

423

E-Print Network 3.0 - absorption spectrometry analyticalmethod...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Trace Elements in Biological Tissues by Summary: Block Digestion and Spike-Height Flame Atomic Absorption Spectrometry ,.. U. TINGGI AND W. MAHER School... absorption...

424

Compact mass spectrometer for plasma discharge ion analysis  

DOE Patents [OSTI]

A mass spectrometer and methods for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector.

Tuszewski, Michel G. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

425

Compact mass spectrometer for plasma discharge ion analysis  

DOE Patents [OSTI]

A mass spectrometer and methods are disclosed for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector. 7 figs.

Tuszewski, M.G.

1997-07-22T23:59:59.000Z

426

CAMD Cleanroom Chemical List  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

CAMD Cleanroom Chemical List Chemicals on this list are routine use chemicals in the CAMD Cleanroom and are available to users for general use. All others (*) are approved for use...

427

Chemical and Mutagenic Investigations of Fatty Acid Amide Hydrolase:? Evidence for a Family of Serine Hydrolases with Distinct Catalytic Properties  

Science Journals Connector (OSTI)

Matthew P. Patricelli , Martha A. Lovato , and Benjamin F. Cravatt * ... We thank Phil Dawson and Ashraf Brik for use of and assistance with the Sciex API III mass spectrometer, Gary Siuzdak and Jiang Wu for performing tandem mass spectrometry experiments, Mike Petrassi for assistance with CD measurements, and Jeffery Kelly, Paul Schimmel, Norton Gilula, and Michael Bracey for helpful suggestions with the manuscript. ...

Matthew P. Patricelli; Martha A. Lovato; Benjamin F. Cravatt

1999-07-16T23:59:59.000Z

428

chemical analysis | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

chemical analysis chemical analysis Leads No leads are available at this time. Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. Abstract: As a...

429

TRENDS in Chemical Marketing  

Science Journals Connector (OSTI)

TRENDS in Chemical Marketing ... BEFORE any chemical sales organization, can meet or establish new trends in marketing, it must be completely aware of the problem it faces. ...

W. M. RUSSELL

1955-08-29T23:59:59.000Z

430

Determination of tritium distribution in labeled compounds using EPR spectrometry  

SciTech Connect (OSTI)

Usually, the tritium distribution in a labeled compound is analyzed by T-NMR spectrometry. NMR equipment is expensive and its sensitivity is lower in comparison to EPR spectrometry. In this paper, the possibility of determining the distribution of tritium in a labeled molecule using self-radiolytic decay processes was analyzed. (authors)

Postolache, C.; Matei, L.; Georgescu, R. [Horia Hulubei, National Inst. for Physics and Nuclear Engineering IFIN HH, 407 Atomistilor street, 077125 Magurele Ilfov (Romania)

2008-07-15T23:59:59.000Z

431

E-Print Network 3.0 - atomic fluorescence spectrometry Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

avril1994 Summary: down to about 310 nm. Such powers are sufficient for laser atomic absorption spectrometry (LAAS... spectrometry where the low-frequency noise of the...

432

E-Print Network 3.0 - absorption spectrometry faas Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Marco A. Z. Arruda* Summary: for metal determination is normally carried out by flame atomic absorption spectrometry (FAAS). The main... atomic absorption spectrometry (FAAS)...

433

E-Print Network 3.0 - absorption spectrometry combination Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Analytical combining RINH and IMS facilities RINH Genomics will re locate... absorption spectrometry Atomic fluorescence spectrometry (As, Se, Hg) Contact Joerg...

434

Formaldehyde and Other Volatile Organic Chemical Emissions in Four FEMA  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Formaldehyde and Other Volatile Organic Chemical Emissions in Four FEMA Formaldehyde and Other Volatile Organic Chemical Emissions in Four FEMA Temporary Housing Units Title Formaldehyde and Other Volatile Organic Chemical Emissions in Four FEMA Temporary Housing Units Publication Type Journal Article Year of Publication 2009 Authors Maddalena, Randy L., Marion L. Russell, Douglas P. Sullivan, and Michael G. Apte Journal Environmental Science and Technology Volume 43 Start Page Chapter Pagination 5626-5632 Publisher Lawrence Berkeley National Laboratory Abstract Four unoccupied FEMA temporary housing units (THUs) were studied to assess their indoor emissions of volatile organic compounds including formaldehyde. Measurement of whole-THUVOC and aldehyde emission factors (µg h-1 per m2 of floor area) for each of the four THUs were made at FEMA's Purvis MS staging yard using a mass balance approach. Measurements were made in the morning, and again in the afternoon in each THU. Steady-state indoor formaldehydeconcentrations ranged from 378 µg m-3 (0.31ppm) to 632 µg m-3 (0.52 ppm) in the AM, and from 433 µg m-3 (0.35 ppm) to 926 µg m-3 (0.78 ppm) in the PM. THU air exchange rates ranged from 0.15 h-1 to 0.39 h-1. A total of 45 small (approximately 0.025 m2) samples of surface material, 16 types, were collected directly from the four THUs and shipped to Lawrence Berkeley Laboratory. The material samples were analyzed for VOC and aldehyde emissions in small stainless steel chambers using a standard, accurate mass balance method. Quantification of VOCs was done via gas chromatography - mass spectrometry and low molecular weight aldehydes via high performance liquid chromatography. Material specific emission factors (µg h-1 per m2 of material) were quantified. Approximately 80 unique VOCs were tentatively identified in the THU field samples, of which forty-five were quantified either because of their toxicological significance or because their concentrations were high. Whole-trailer and materialspecific emission factors were calculated for 33 compounds. The THU emission factors and those from their component materials were compared against those measured from other types of housing and the materials used in their construction. Whole THU emission factors for most VOCs were typically similar to those from comparative housing. The three exceptions were exceptionally large emissions of formaldehyde and TMPD-DIB (a common plasticizer in vinyl products), and somewhat elevated for phenol. Of these three compounds, formaldehyde was theonly one with toxicological significance at the observed concentrations. Whole THU formaldehyde emissions ranged from 173 to 266 µg m-2 h-1 in the morning and 257 to 347 µg m-2 h-1 in the afternoon. Median formaldehyde emissions in previously studied site-built and manufactured homes were 31 and 45 µg m-2 h-1, respectively. Only one of the composite wood materials that was tested appeared to exceed the HUD formaldehyde emission standard (430 µg/m2 h-1 for particleboard and 130 µg/m2 h-1 for plywood). The high loading factor (materialsurface area divided by THU volume) of composite wood products in the THUs and the low fresh air exchange relative to the material surface area may be responsible for the excessive concentrations observed for some of the VOCs and formaldehyde

435

Chemical Safety Program  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Program Program Home Chemical Safety Topical Committee Library Program Contacts Related Links Site Map Tools 2013 Chemical Safety Workshop Archived Workshops Contact Us Health and Safety HSS Logo Chemical Safety Program logo The Department of Energy's (DOE's) Chemical Safety web pages provide a forum for the exchange of best practices, lessons learned, and guidance in the area of chemical management. This page is supported by the Chemical Safety Topical Committee which was formed to identify chemical safety-related issues of concern to the DOE and pursue solutions to issues identified. Noteworthy products are the Chemical Management Handbooks and the Chemical Lifecycle Cost Analysis Tool, found under the TOOLS menu. Chemical Management Handbook Vol (1) Chemical Management Handbook Vol (2)

436

Chemical Management Contacts  

Broader source: Energy.gov [DOE]

Contacts for additional information on Chemical Management and brief description on Energy Facility Contractors Group

437

Charge exchange and chemical reactions with trapped Th{sup 3+}  

SciTech Connect (OSTI)

We have measured the reaction rates of trapped, buffer gas cooled Th{sup 3+} and various gases and have analyzed the reaction products using trapped ion mass spectrometry techniques. Ion trap lifetimes are usually limited by reactions with background molecules, and the high electron affinity of multiply charged ions such as Th{sup 3+} make them more prone to loss. Our results show that reactions of Th{sup 3+} with carbon dioxide, methane, and oxygen all occur near the classical Langevin rate, while reaction rates with argon, hydrogen, and nitrogen are orders of magnitude lower. Reactions of Th{sup 3+} with oxygen and methane proceed primarily via charge exchange, while simultaneous charge exchange and chemical reaction occurs between Th{sup 3+} and carbon dioxide. Loss rates of Th{sup 3+} in helium are consistent with reaction with impurities in the gas. Reaction rates of Th{sup 3+} with nitrogen and argon depend on the internal electronic configuration of the Th{sup 3+}.

Churchill, L. R.; DePalatis, M. V.; Chapman, M. S. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States)

2011-01-15T23:59:59.000Z

438

Method and apparatuses for ion cyclotron spectrometry  

DOE Patents [OSTI]

An ion cyclotron spectrometer may include a vacuum chamber that extends at least along a z-axis and means for producing a magnetic field within the vacuum chamber so that a magnetic field vector is generally parallel to the z-axis. The ion cyclotron spectrometer may also include means for producing a trapping electric field within the vacuum chamber. The trapping electric field may comprise a field potential that, when taken in cross-section along the z-axis, includes at least one section that is concave down and at least one section that is concave up so that ions traversing the field potential experience a net magnetron effect on a cyclotron frequency of the ions that is substantially equal to zero. Other apparatuses and a method for performing ion cyclotron spectrometry are also disclosed herein.

Dahl, David A. (Idaho Falls, ID); Scott, Jill R. (Idaho Falls, ID); McJunkin, Timothy R. (Idaho Falls, ID)

2012-03-06T23:59:59.000Z

439

About Chemical Hazards  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Chemical Hazards Chemical Hazards What Is a Chemical Hazard? chemical hazards.jpg A chemical hazard is any substance that can cause harm, primarily to people. Chemicals of all kinds are stored in our homes and can result in serious injuries if not properly handled. Household items such as bleach can result in harmful chlorine gas or hydrochloric acid if carelessly used. Gasoline fumes from containers for lawnmowers or boats can result in major health hazards if inhaled. DOE Oak Ridge uses thousands of chemicals in its varied research and other operations. New chemicals are or can be created as a result of the research or other activities. DOE follows national safety requirements in storing and handling these chemicals to minimize the risk of injuries from its chemical usage. However, accidents can occur despite careful attention to proper handling and storage procedures.

440

10.34 Numerical Methods Applied to Chemical Engineering, Fall 2001  

E-Print Network [OSTI]

Numerical methods for solving problems arising in heat and mass transfer, fluid mechanics, chemical reaction engineering, and molecular simulation. Topics: numerical linear algebra, solution of nonlinear algebraic equations ...

Beers, Kenneth J.

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Chemicals from Biomass: Petrochemical Substitution Options  

Science Journals Connector (OSTI)

...strategies to substitute for petrochemicals...COAL-BASED SYNGAS, CHEMTECH...SYNTHESIS GAS - A RAW-MATERIAL...strategies to substitute for petrochemicals...petroleum and natural gas liquids...programs to substitute bio-mass-derived...Petroleum and Natural Gas for Chemical...

E. S. Lipinsky

1981-06-26T23:59:59.000Z

442

Chip-scale quadrupole mass filters for a Micro-Gas Analyzer  

E-Print Network [OSTI]

Mass spectrometers are powerful analytical instruments that serve as the gold standard for chemical analysis. This tool has numerous applications ranging from national security, industrial processing, environmental monitoring, ...

Cheung, Kerry

2009-01-01T23:59:59.000Z

443

Ion-mobility Spectrometry Based NOx Sensor - Nuclear Engineering Division  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

NPNS > Sensors and NPNS > Sensors and Instrumentation and NDE > Energy System Application > DOE Office of Transportation Technologies > Ion-mobility Spectrometry Based NOx Sensor Capabilities Sensors and Instrumentation and Nondestructive Evaluation Overview Energy System Applications Overview DOE Office of Fossil Energy DOE Office of Transportation Technologies Ion-mobility Spectrometry Based NOx Sensor DOE Office of Power Technology Work for Others Safety-Related Applications Homeland Security Applications Biomedical Applications Millimiter Wave Group Papers Other NPNS Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Sensors and Instrumentation and Nondestructive Evaluation Ion-mobility Spectrometry Based NOx Sensor

444

Method of trivalent chromium concentration determination by atomic spectrometry  

DOE Patents [OSTI]

A method is disclosed for determining the concentration of trivalent chromium Cr(III) in a sample. The addition of perchloric acid has been found to increase the atomic chromium spectrometric signal due to Cr(III), while leaving the signal due to hexavalent chromium Cr(VI) unchanged. This enables determination of the Cr(III) concentration without pre-concentration or pre-separation from chromium of other valences. The Cr(III) concentration may be measured using atomic absorption spectrometry, atomic emission spectrometry or atomic fluorescence spectrometry.

Reheulishvili, Aleksandre N. (Tbilisi, 0183, GE); Tsibakhashvili, Neli Ya. (Tbilisi, 0101, GE)

2006-12-12T23:59:59.000Z

445

Mass spectrometer having a derivatized sample presentation apparatus  

DOE Patents [OSTI]

A mass spectrometer having a derivatized sample presentation apparatus is provided. The sample presentation apparatus has a complex bound to the surface of the sample presentation apparatus. This complex includes a molecule which may chemically modify a biomolecule.

Nelson, Randall W. (Phoenix, AZ)

2000-07-25T23:59:59.000Z

446

Synchronized B and 13 C Diamond Delta Structures for an Ultimate In-Depth Chemical Characterization  

E-Print Network [OSTI]

of secondary ion mass spectrometry (SIMS) profiles in diamond was achieved by the determination of the depth resolution function (DRF). The measurement of this DRF was performed thanks to isotopic-enriched diamond. Applied to boron delta-doped diamond structures, this analysis has resolved edge widths close to 0.3 nm

Paris-Sud XI, Université de

447

Sunflower as a biofuels crop: An analysis of lignocellulosic chemical properties  

E-Print Network [OSTI]

Lignocellulosic biofuel Lignin S/G-lignin Sugar content Pyrolysis Molecular Beam Mass Spectrometry a b s t r a c grown in Georgia and Iowa was assessed using analytical wet chemistry methods to measure lignin and sugar content/ composition. The analysis of lignin and the S/G-lignin ratios for a larger number

Burke, John M.

448

The multi-layered protective cuticle of Collembola: a chemical analysis  

Science Journals Connector (OSTI)

...habitats, enabling the permeability to gases, minimizing liquid wettability and fouling...staining (Sigma-Aldrich) [45]. 4.6. Gas chromatography mass spectrometry Hexane...Nat. Hist. Soc. 1960, 138-154. 20 Hale, WG , and AL Smith. 1966 Scanning electron...

2014-01-01T23:59:59.000Z

449

Z .Chemical Geology 157 1999 219234 z /Quantifying the platinum group elements PGEs and gold in  

E-Print Network [OSTI]

-mass z /spectrometry USN-ICP-MS James C. Ely ) , Clive R. Neal, James A. O'Neill Jr., Jinesh C. Jain thereof e.g., Alvarez et al., 1980; Kyte et al., 1980, 1985; O'Neill, 1991; Evans et al., .1993, 1995

450

Laboratory investigation of chemical and physical properties of soot-containing aerosols  

E-Print Network [OSTI]

SO4-coated soot aerosols; (3) effect of H2SO4 coating on scattering and extinction properties of soot particles. A low-pressure laminar-flow reactor, coupled to ion driftchemical ionization mass spectrometry (ID-CIMS) detection, is used to study...

Zhang, Dan

2006-08-16T23:59:59.000Z

451

Mass Balance of Gaseous and Particulate Products from ?-Pinene/O3/Air in the Absence of Light and ?-Pinene/NOx/Air in the Presence of Natural Sunlight  

Science Journals Connector (OSTI)

The gas and particle phase products from the reaction of ?-pinene with the atmospheric oxidants O3 and OH radicals in the presence of NOx were investigated using both gas chromatography-mass spectrometry (GC-MS) ...

M. Jaoui; R. M. Kamens

2003-06-01T23:59:59.000Z

452

Spatially-Correlated Mass Spectrometric Analysis of Microbe-Mineral Interactions  

SciTech Connect (OSTI)

A new methodology for examining the interactions of microbes with heterogeneous minerals is presented. Imaging laser-desorption Fourier transform mass spectrometry was used to examine the colonization patterns of Burkholderia vietnamiensis (Burkholderia cepacia) G4 on a heterogeneous basalt sample. Depth-profile imaging found that the bacterium preferentially colonized the plagioclase mineral phases within the basalt.

Jill R. Scott; Beizhan Yan; Daphne L. Stoner

2006-11-01T23:59:59.000Z

453

Cosmological implications of dwarf spheroidal chemical evolution  

E-Print Network [OSTI]

The chemical properties of dwarf spheroidals in the local group are shown to be inconsistent with star formation being truncated after the reionization epoch (z~8). Enhanced levels of [Ba/Y] in stars in dwarf spheroidals like Sculptor indicate strong s-process production from low-mass stars whose lifetimes are comparable with the duration of the pre-reionization epoch. The chemical evolution of Sculptor is followed using a model with SNeII and SNeIa feedback and mass- and metallicity-dependent nucleosynthetic yields for elements from H to Pb. We are unable to reproduce the Ba/Y ratio unless stars formed over an interval long enough for the low-mass stars to pollute the interstellar medium with s-elements. This robust result challenges the suggestion that most of the local group dwarf spheroidals are fossils of reionization and supports the case for large initial dark matter halos.

Fenner, Y; Gallino, R; Lugaro, M; Fenner, Yeshe; Gibson, Brad K.; Gallino, Roberto; Lugaro, Maria

2006-01-01T23:59:59.000Z

454

Cosmological implications of dwarf spheroidal chemical evolution  

E-Print Network [OSTI]

The chemical properties of dwarf spheroidals in the local group are shown to be inconsistent with star formation being truncated after the reionization epoch (z~8). Enhanced levels of [Ba/Y] in stars in dwarf spheroidals like Sculptor indicate strong s-process production from low-mass stars whose lifetimes are comparable with the duration of the pre-reionization epoch. The chemical evolution of Sculptor is followed using a model with SNeII and SNeIa feedback and mass- and metallicity-dependent nucleosynthetic yields for elements from H to Pb. We are unable to reproduce the Ba/Y ratio unless stars formed over an interval long enough for the low-mass stars to pollute the interstellar medium with s-elements. This robust result challenges the suggestion that most of the local group dwarf spheroidals are fossils of reionization and supports the case for large initial dark matter halos.

Yeshe Fenner; Brad K. Gibson; Roberto Gallino; Maria Lugaro

2006-02-22T23:59:59.000Z

455

Responding to Mass Psychogenic Illness  

Science Journals Connector (OSTI)

...outbreaks have not been reported. In a previous era, spirits and demons oppressed us. Although they have been replaced by our contemporary concern about invisible viruses, chemicals, and toxins, the mechanisms of contagious fear remain the same. The rapid outbreak of illness described by Jones et al. the particular... In this issue of the Journal, Jones and colleagues report on an episode of mass psychogenic illness that had a devastating impact on a high school in McMinnville, Tennessee.1 They provide an elegant description of the outbreak. Such outbreaks, ...

Wessely S.

2000-01-13T23:59:59.000Z

456

Measurement of Gas Hydrate by Laser Raman Spectrometry  

Science Journals Connector (OSTI)

Four types of natural sand (respectively 250–350, 180–250, 125 ... ) are used as media to synthesize methane hydrate that is measured by laser Raman spectrometry. ... show that sediment grain sizes do not influen...

Changling Liu; Qingguo Meng; Yuguang Ye

2013-01-01T23:59:59.000Z

457

Atomic Absorption Spectrometry Perkin Elmer 500, Chemistry & Biochemistry  

E-Print Network [OSTI]

Atomic Absorption Spectrometry · Perkin Elmer 500, Chemistry & Biochemistry · Perkin Elmer 560 AA-star stopped flow with absorption, fluorescence and circular dichroism detection · KinTek quench flow apparatus

Gruner, Daniel S.

458

Mass Transfer Constraints On The Chemical Evolution Of An Active...  

Open Energy Info (EERE)

Valles caldera relative to other hydrothermal systems in rhyolitic rocks. Authors Art F White, Nancy J Chuma and Fraser E. Goff Published Journal Journal of Volcanology and...

459

Volatiles in hydrothermal fluids- A mass spectrometric study of fluid  

Open Energy Info (EERE)

Volatiles in hydrothermal fluids- A mass spectrometric study of fluid Volatiles in hydrothermal fluids- A mass spectrometric study of fluid inclusions from active geothermal systems Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Volatiles in hydrothermal fluids- A mass spectrometric study of fluid inclusions from active geothermal systems Details Activities (4) Areas (4) Regions (0) Abstract: A system for analysis of inclusion gas contents based upon quadrupole mass spectrometry has been designed, assembled and tested during the first 7 months of funding. The system is currently being tested and calibrated using inclusions with known gas contents from active geothermal systems. Analyses are in progress on inclusions from the Salton Sea, Valles Caldera, Geysers, and Coso geothermal systems. Author(s): Mckibben, M. A.

460

Capacitive chemical sensor  

DOE Patents [OSTI]

A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

2014-05-27T23:59:59.000Z

Note: This page contains sample records for the topic "mass spectrometry chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Chemicals from Metabolic Pathways  

Science Journals Connector (OSTI)

A few basic raw materials, petroleum, natural gas, +S from oil or natural gas, and O2 + N2 from air, generate first primary (or platform) chemicals, next secondary (commodity) chemicals, then intermediates, and f...

John Villadsen; Jens Nielsen; Gunnar Lidén

2011-01-01T23:59:59.000Z

462

Chemistry 455 Chemical Nanotechnology  

E-Print Network [OSTI]

Chemistry 455 Chemical Nanotechnology 4 units Prof. Richard Brutchey, Fall 2014 (Lecture = 12:00�12:50 pm MWF) CHEM 455 is an upper-division undergraduate course in Chemical Nanotechnology. The intent

Rohs, Remo

463

Chemicals and health  

Science Journals Connector (OSTI)

Chemicals and health ... I must add here that some chemicals are indeed dangerous in the environment, largely because they persist, they don't break down, and they can therefore build up in the food chain. ...

1980-11-03T23:59:59.000Z

464

Safeguards Verification Measurements using Laser Ablation, Absorbance Ratio Spectrometry in Gaseous Centrifuge Enrichment Plants  

SciTech Connect (OSTI)

Laser Ablation Absorbance Ratio Spectrometry (LAARS) is a new verification measurement technology under development at the US Department of Energy (DOE) Pacific Northwest National Laboratory (PNNL). LAARS uses three lasers to ablate and then measure the relative isotopic abundance of uranium compounds. An ablation laser is tightly focused on uranium-bearing solids, producing a small atomic uranium vapor plume. Two collinear wavelength-tuned spectrometry lasers transit through the plume and the absorbance of U-235 and U-238 isotopes are measured to determine U-235 enrichment. The measurement is independent of chemical form and degree of dilution with nuisance dust and other materials. LAARS has high relative precision and detection limits approaching the femtogram range for U-235. The sample is scanned and assayed point-by-point at rates reaching 1 million measurements/hour, enabling LAARS to detect and analyze uranium in trace samples. The spectrometer is assembled using primarily commercially available components and features a compact design and automated analysis.Two specific gaseous centrifuge enrichment plant (GCEP) applications of the spectrometer are currently under development: 1) LAARS-Environmental Sampling (ES), which collects and analyzes aerosol particles for GCEP misuse detection and 2) LAARS-Destructive Assay (DA), which enables onsite enrichment DA sample collection and analysis for protracted diversion detection. The two applications propose game-changing technological advances in GCEP safeguards verification.

Anheier, Norman C.; Cannon, Bret D.; Kulkarni, Gourihar R.; Munley, John T.; Nelson, Danny A.; Qiao, Hong (Amy) [Amy; Phillips, Jon R.

2012-07-17T23:59:59.000Z

465

Biobased Chemicals Without Biomass  

Science Journals Connector (OSTI)

Unlike most other companies using biology to make chemicals, LanzaTech does not rely on biomass feedstocks. ...

MELODY BOMGARDNER

2012-08-27T23:59:59.000Z

466

Institute of Chemical Engineering and High Temperature Chemical...  

Open Energy Info (EERE)

Chemical Processes ICEHT Jump to: navigation, search Name: Institute of Chemical Engineering and High Temperature Chemical Processes (ICEHT) Place: Hellas, Greece Zip:...

467

HARVARD UNIVERSITY CHEMICAL BIOLOGY  

E-Print Network [OSTI]

HARVARD UNIVERSITY CHEMICAL BIOLOGY PHD PROGRAM 2013-2014 Student Handbook #12;Program Contacts at the beginning of each semester. Laboratory Rotations Students in the Chemical Biology Program are expected an interest in having Chemical Biology Program Students in their labs. Students may rotate in the labs

Church, George M.

468

Computational Chemical Materials Engineering  

E-Print Network [OSTI]

: Thermal barrier coatings, wear resistance coatings, radiation resistant materials · Materials for opticalHome Computational Chemical an