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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.


1

Developing Fieldable Systems for Chemical Sensing Using Field Asymmetric Ion Mobility Spectrometry and Mass Spectrometry  

SciTech Connect

Currently, there is an urgent need for field-rugged and field-programmable sensor systems that provide highly selective, universal monitoring of vapors and aerosols at detectable levels from persons or areas involved with illicit chemical/biological/explosives (CBE) production. These devices must be portable, low cost, robust, and provide accurate measurements to avoid both false positive and negative results. Furthermore, the information provided by the devices must be received in a timely manner so that informed decisions can be immediately made and the appropriate actions taken. Two technologies that are unparalleled in their sensitivity, selectivity, and trace-level detection capabilities are field asymmetric ion mobility spectrometry (FAIMS) and mass spectrometry. Here, we will show progress that has been made toward developing fieldable FAIMS systems and mass spectrometers. Working in collaboration with Sionex Corporation, the microDMx detector was equipped with a continuous air sampling system to develop selective methods for the analysis of compounds of interest. A microdiaphragm pump (KNF Neuberger, Inc.) is used to pull in gas-phase analytes directly from the air for separation and detection with the FAIMS system. The FAIMS evaluation platform (SVAC) unit currently measures 9.8-inch x 4.6-inch x 3.2-inch, weighs 3.1 lb, and utilizes a {sup 63}Ni source to ionize incoming compounds. Analytes entering the unit are separated and identified by their characteristic response to the compensation voltage (V{sub c}) at a given rf field strength (V{sub rf}). This response has been observed to be unique for a wide range of substances studied. If additional verification were required or a targeted analyte present in a complex chemical matrix, a FAIMS unit equipped with a fast gas chromatography column has been evaluated. The unit combines the separation capabilities of gas chromatography with the selectivity of FAIMS. It measures 9.5-inch x 5.25-inch x 3.5-inch, weighs 3.8 lb, and uses a 10.6 eV photoionization source. Analytes are identified both by their elution time from the column and by the characteristic response in the FAIMS spectrum. Analysis times required to obtain results for most analytes examined are less than three minutes. A fieldable mass spectrometer system is also being developed that includes sampling, ionization, mass selection and detection, vacuum technology, and analytical methodology with remote data transmission. Multiple methods for mass selection are being explored, including both Penning and Paul type ion traps as well as a quadrupole system to determine which is best suited for a portable mass spectrometer. Several ionization sources and ion counting methods will also be evaluated to establish their effectiveness with each system. The intended result of this project is a handheld mass spectrometer system capable of field deployment for the detection and identification of a wide range of gas-phase CBE species.

Kevin Kyle, Stephan Weeks, R. Trainham

2008-03-01T23:59:59.000Z

2

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

E-Print Network (OSTI)

Chemical and Biological Systems Research Team: Julia Laskin, Ljiljana Pasa-Toli, Brandi Heath, Ingela Laskin (PNNL) Purpose Multimodal chemical characterization of microbial biofilms focused bacterial colonies Develop novel mass spectrometry-based chemical imaging capabilities broadly applicable

3

Laser Microdissection and Atmospheric Pressure Chemical Ionization Mass Spectrometry Coupled for Multimodal Imaging  

SciTech Connect

This paper describes the coupling of ambient laser ablation surface sampling, accomplished using a laser capture microdissection system, with atmospheric pressure chemical ionization mass spectrometry for high spatial resolution multimodal imaging. A commercial laser capture microdissection system was placed in close proximity to a modified ion source of a mass spectrometer designed to allow for sampling of laser ablated material via a transfer tube directly into the ionization region. Rhodamine 6G dye of red sharpie ink in a laser etched pattern as well as cholesterol and phosphatidylcholine in a cerebellum mouse brain thin tissue section were identified and imaged from full scan mass spectra. A minimal spot diameter of 8 m was achieved using the 10X microscope cutting objective with a lateral oversampling pixel resolution of about 3.7 m. Distinguishing between features approximately 13 m apart in a cerebellum mouse brain thin tissue section was demonstrated in a multimodal fashion including co-registered optical and mass spectral chemical images.

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

2013-01-01T23:59:59.000Z

4

Theoretical Mass Spectrometry  

Science Conference Proceedings (OSTI)

... Mass spectrometry is an important technique in analytical chemistry, essential in areas including drug development, criminal ... Facilities/Tools Used: ...

2013-03-19T23:59:59.000Z

5

Modern Methods for Lipid AnalysisChapter 8 Analysis of Carotenoids Using Atmospheric Pressure Chemical Ionization Mass Spectrometry  

Science Conference Proceedings (OSTI)

Modern Methods for Lipid Analysis Chapter 8 Analysis of Carotenoids Using Atmospheric Pressure Chemical Ionization Mass Spectrometry Methods and Analyses eChapters Methods - Analyses Books AOCS Press 634F787D8F694E5A50C242671C4B87C5

6

EMSL: Capabilities: Mass Spectrometry Experts  

NLE Websites -- All DOE Office Websites (Extended Search)

Related EMSL User Projects Mass Spectrometry Tools are Applied to all Science Themes Next-Generation Mass Spectrometry Proteomics Research Resource for Integrative Biology...

7

Modern Methods for Lipid AnalysisCh 6 Regiospecific Analysis of Triacylglycerols using Hi Performance Liquid Chromatography/AtmosphericPressure Chemical Ionization Mass Spectrometry  

Science Conference Proceedings (OSTI)

Modern Methods for Lipid Analysis Ch 6 Regiospecific Analysis of Triacylglycerols using Hi Performance Liquid Chromatography/AtmosphericPressure Chemical Ionization Mass Spectrometry Methods and Analyses eChapters Methods - Analyses Books

8

Advances in Conjugated Linoleic Acid Research, Volume 3Chapter 6 Structural Characterization of CLA Methyl Esters with Acetonitrile Chemical Ionization Tandem Mass Spectrometry  

Science Conference Proceedings (OSTI)

Advances in Conjugated Linoleic Acid Research, Volume 3 Chapter 6 Structural Characterization of CLA Methyl Esters with Acetonitrile Chemical Ionization Tandem Mass Spectrometry Health Nutrition Biochemistry eChapters Health - Nutrition

9

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

NLE Websites -- All DOE Office Websites (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,

10

Chemical Analysis of Complex Organic Mixtures Using Reactive Nanospray Desorption Electrospray Ionization Mass Spectrometry  

SciTech Connect

Reactive nanospray desorption electrospray ionization (nano-DESI) combined with high-resolution mass spectrometry was utilized for the analysis of secondary organic aerosol produced through ozonolysis of limonene (LSOA). Previous studies showed that LSOA constituents are multifunctional compounds containing aldehyde and ketone groups. In this study, we used the selectivity of the Girard T (GT) reagent towards carbonyl compounds to examine the utility of reactive nano-DESI for the analysis of complex organic mixtures. In these experiments, 1-100 {micro}M GT solution was used as a working solvent for reactive nano-DESI analysis. Abundant products of a single addition of GT to LSOA constituents were observed at GT concentrations in excess of 10 {micro}M. We found that LSOA compounds with 18-20 carbon atoms (dimers) and 27-30 carbon atoms (trimers) react with GT through a simple addition reaction resulting in formation of the carbinolamine derivative. In contrast, reactions of GT with monomeric species result in formation of both the carbinolamine and the hydrazone derivatives. In addition, several monomers did not react with GT on the timescale of our experiment. These molecules were characterized by relatively high values of the double bond equivalent (DBE) and low oxygen content. Furthermore, because addition of a charged GT tag to a neutral molecule eliminates the discrimination against the low proton affinity compounds in the ionization process, reactive nano-DESI analysis enables quantification of individual compounds in the complex mixture. For example, we were able to estimate for the first time the amounts of dimers and trimers in the LSOA mixture. Specifically, we found that the most abundant LSOA dimer was detected at ca. 0.5 pg level and the total amount of dimers and trimers in the analyzed sample was just around 11 pg. Our results indicate that reactive nano-DESI is a valuable approach for examining the presence of specific functional groups and quantification of compounds possessing these groups in complex mixtures.

Laskin, Julia; Eckert, Peter A.; Roach, Patrick J.; Heath, Brandi S.; Nizkorodov, Sergey A.; Laskin, Alexander

2012-08-21T23:59:59.000Z

11

Single event mass spectrometry  

DOE Patents (OSTI)

A means and method for single event time of flight mass spectrometry for analysis of specimen materials. The method of the invention includes pulsing an ion source imposing at least one pulsed ion onto the specimen to produce a corresponding emission of at least one electrically charged particle. The emitted particle is then dissociated into a charged ion component and an uncharged neutral component. The ion and neutral components are then detected. The time of flight of the components are recorded and can be used to analyze the predecessor of the components, and therefore the specimen material. When more than one ion particle is emitted from the specimen per single ion impact, the single event time of flight mass spectrometer described here furnis This invention was made with Government support under Contract No. W-7405-ENG82 awarded by the Department of Energy. The Government has certain rights in the invention.

Conzemius, Robert J. (Ames, IA)

1990-01-16T23:59:59.000Z

12

Differential Mobility Spectrometry/Mass Spectrometry: The Design of a New Mass Spectrometer for Real-Time Chemical Analysis in the Field  

SciTech Connect

The design of a prototype, field-portable mass spectrometer (MS) is described. The MS has been designed with an atmospheric interface in order to couple the system to a commercially available differential mobility spectrometer. The differential mobility spectrometer provides selective injection of trace-level analytes of interest into the inlet of the MS for real-time chemical detection. To accomplish this task, the MS design incorporates the use of an electrodynamic ion funnel to transport the ion beam, generated at atmospheric pressure, to the high-vacuum chamber that houses the mass analyzer. This leads to a design that utilizes two stages of differential pumping to achieve an overall pressure drop from atmosphere (760 Torr) to approximately 1 ×

,

2010-08-01T23:59:59.000Z

13

In situ mass spectrometry in a 10 Torr W chemical vapor deposition process for film thickness metrology  

E-Print Network (OSTI)

widely implemented using in situ sensors, par- ticularly using mass spectrometry or residual gas analysis-process ex situ film weight measurement, provided a working metrology model such that real-time mass spec- cess chemistry, temperature regime, and low-pressure sub- Torr operation of the reactor. Our analysis

Rubloff, Gary W.

14

EMSL: Capabilities: Mass Spectrometry  

NLE Websites -- All DOE Office Websites (Extended Search)

Five linear ion traps (one with ETD) Three triple-quadrupole spectrometers Three ion mobility spectrometry (IMS) - time-of-flight (TOF) spectrometers Seventeen custom HPLC,...

15

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer and methods for mass spectrometry. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field.

McComas, David J. (Los Alamos, NM); Nordholt, Jane E. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

16

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer and methods for mass spectrometry are described. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field. 8 figs.

McComas, D.J.; Nordholt, J.E.

1992-12-01T23:59:59.000Z

17

Combination of chemical reduction and tandem mass spectrometry for the characterization of sulfur-containing fuel constituents  

SciTech Connect

Tandem mass spectrometry has been combined with a calcium/mixed amines reduction system to characterize an SRC-II middle distillate fraction for sulfur-containing polynuclear aromatic hydrocarbons. Parent scans, which characterize a complex mixture for all components which fragment to common structural moieties, were used to identify alkyl-benzothiophenes and dibenzothiophenes as well as alkyl-benzothiophene sulfones. 15 references, 5 figures, 1 table.

Wood, K.V.; Cooks, R.G.; Laugal, J.A.; Benkeser, R.A.

1985-03-01T23:59:59.000Z

18

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

19

Instrument Series: Mass Spectrometry SPLAT II  

NLE Websites -- All DOE Office Websites (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

20

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

Science Conference Proceedings (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

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

Accelerator Mass Spectrometry: Extreme Sensitivity in Biological ...  

THE LLNL TECHNOLOGY COMPANY PRODUCT 24 Partnering Today: Technology Transfer Highlights Accelerator Mass Spectrometry: Extreme Sensitivity in Biological Research

22

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

23

Available Technologies: Nanostructure Initiator Mass Spectrometry ...  

Using time dependent isotopic labeling and mass spectrometry imaging, researchers at Berkeley Lab and the University of California, Berkeley have developed a ...

24

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

25

Automated Surface Sampling Probe for Mass Spectrometry  

Dr. Gary Van Berkel and colleagues have developed a liquid microjunction surface sampling probe (LMJ?SSP). The LMJ?SSP provides mass spectrometry with ...

26

Final Technical Report for DE-FG02-06ER15835: Chemical Imaging with 100nm Spatial Resolution: Combining High Resolution Flurosecence Microscopy and Ion Mobility Mass Spectrometry  

SciTech Connect

We have combined, in a single instrument, high spatial resolution optical microscopy with the chemical specificity and conformational selectivity of ion mobility mass spectrometry. We discuss the design and construction of this apparatus as well as our efforts in applying this technique to thin films of molecular semiconductor materials.

Buratto, Steven K. [UC Santa Barbara

2013-09-03T23:59:59.000Z

27

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

E-Print Network (OSTI)

mass fractions in particles. Aerosol Science and Technology,mediated lung injury, J. Aerosol Sci. , 29 (5-6), 553-560,from natural to anthropogenic aerosol radiative forcing:

Spencer, Matthew Todd

2007-01-01T23:59:59.000Z

28

Giga-Dalton Mass Spectrometry  

Current techniques to study large bio?molecules using mass spectrometer require fragmentation for the mass?to?charge ratios to be within the working range of the mass spectrometer. Analysis of the data is complex and often requires simulation ...

29

High-Performance Mass Spectrometry Facility  

NLE Websites -- All DOE Office Websites (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

30

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer is described having a low weight and low power requirement, for use in space. It can be used to analyze the ionized particles in the region of the spacecraft on which it is mounted. High mass resolution measurements are made by timing ions moving through a gridless cylindrically sysmetric linear electric field.

McComas, D.J.; Nordholt, J.E.

1991-03-29T23:59:59.000Z

31

Tropospheric Aerosol Chemistry via Aerosol Mass Spectrometry  

NLE Websites -- All DOE Office Websites (Extended Search)

chemical information needed to interpret mass spectra. The challenge is to separate primary and secondary; anthropogenic, biogenic and biomass burning sources - and...

32

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

33

Emerging Technologies in Mass Spectrometry Imaging  

E-Print Network (OSTI)

Mass spectrometry imaging (MSI) as an analytical tool for bio-molecular and bio-medical research targets, accurate compound localization and identification. In terms of dedicated instrumentation, this translates into the demand for more detail in the image dimension (spatial resolution) and in the spectral dimension (mass resolution and accuracy), preferably combined in one instrument. At the same time, large area biological tissue samples require fast acquisition schemes, instrument automation and a robust data infrastructure. This review discusses the analytical capabilities of an "ideal" MSI instrument for bio-molecular and bio-medical molecular imaging. The analytical attributes of such an ideal system are contrasted with technological and methodological challenges in MSI. In particular, innovative instrumentation for high spatial resolution imaging in combination with high sample throughput is discussed. Detector technology that targets various shortcomings of conventional imaging detector systems is hig...

Jungmann, Julia H

2013-01-01T23:59:59.000Z

34

Mass-sensitive chemical preconcentrator  

DOE Patents (OSTI)

A microfabricated mass-sensitive chemical preconcentrator actively measures the mass of a sample on an acoustic microbalance during the collection process. The microbalance comprises a chemically sensitive interface for collecting the sample thereon and an acoustic-based physical transducer that provides an electrical output that is proportional to the mass of the collected sample. The acoustic microbalance preferably comprises a pivot plate resonator. A resistive heating element can be disposed on the chemically sensitive interface to rapidly heat and release the collected sample for further analysis. Therefore, the mass-sensitive chemical preconcentrator 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. (Albuquerque, NM); Adkins, Douglas R. (Albuquerque, NM); Lewis, Patrick R. (Albuquerque, NM)

2007-01-30T23:59:59.000Z

35

Secondary Ion Mass Spectrometry of Environmental Aerosols  

Science Conference Proceedings (OSTI)

Atmospheric particles influence many aspects of climate, air quality and human health. Understanding the composition, chemistry and behavior of atmospheric aerosols is a key remaining challenge in improving climate models. Furthermore, particles may be traced back to a particular source based on composition, stable isotope ratios, or the presence of particular surface chemistries. Finally, the characterization of atmospheric particles in the workplace plays an important role in understanding the potential for exposure and environmental and human health effects to engineered and natural nanoscale particles. Secondary ion mass spectrometry (SIMS) is a useful tool in determining any of several aspects of the structure, composition and chemistry of these particles. Often used in conjunction with other surface analysis and electron microscopy methods, SIMS has been used to determine or confirm reactions on and in particles, the presence of particular organic species on the surface of atmospheric aerosols and several other interesting and relevant findings. Various versions of SIMS instruments – dynamic SIMS, time of flight secondary ion mass spectrometry or TOF-SIMS, nanoSIMS – have been used to determine specific aspects of aerosol structure and chemistry. This article describes the strengths of each type of SIMS instrument in the characterization of aerosols, along with guidance on sample preparation, specific characterization specific to the particular information sought in the analysis. Examples and guidance are given for each type of SIMS analysis.

Gaspar, Daniel J.; Cliff, John B.

2010-08-01T23:59:59.000Z

36

High resolution mass spectrometry for the characterization of complex, fossil organic mixtures  

SciTech Connect

High resolution chemical ionization mass spectrometry data support the notion that the size of the stable aromatic clusters is not large in coals except the very high rank coals and inertinite macerals. The desorption chemical ionization spectra appear representative of the sample with little discrimination for molecular types such as aliphatics.

Winans, R.E.; Haas, G.W.; Kim, Yeonhee L.; Hunt, J.E.

1995-08-01T23:59:59.000Z

37

C60 Secondary Ion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry  

SciTech Connect

Secondary ion mass spectrometry (SIMS) has seen increased application for high spatial chemical imaging of complex biological surfaces. The advent and commercial availability of cluster and polyatomic primary ion sources (e.g. Au and Bi cluster and buckminsterfullerene (C60)) provide improved secondary ion yield and decreased fragmentation of surface species, thus accessibility to intact molecular ions. Despite developments in primary ion sources, development of mass spectrometers to fully exploit their advantages has been limited. Tandem mass spectrometry for identification of secondary ions is highly desirable, but implementation has proven to be difficult. Similarly, high mass resolution and high mass measurement accuracy would greatly improve the chemical specificity of SIMS. Here we combine, for the first time, the advantages of a C60 primary ion source with the ultra-high mass resolving power and high mass measurement accuracy of Fourier transform ion cyclotron resonance mass spectrometry. Mass resolving power in excess of 100,000 (m/?m50%) is demonstrated, with mass measurement accuracies below 3 parts-per-million. Imaging of mouse brain tissue at 40 ?m pixel size is shown. Tandem mass spectrometry of ions from biological tissue is demonstrated and molecular formulae can be assigned to fragment ions.

Smith, Donald F.; Robinson, Errol W.; Tolmachev, Aleksey V.; Heeren, Ronald M.; Pasa-Tolic, Ljiljana

2011-12-15T23:59:59.000Z

38

Signal variation in single particle aerosol mass spectrometry  

E-Print Network (OSTI)

Rapid and accurate detection of airborne micro-particles is currently an important problem in national security. One approach to such detection, bioaerosol mass spectrometry (BAMS), is currently under development at Lawrence ...

Wissner-Gross, Zachary Daniel

2007-01-01T23:59:59.000Z

39

Molecular Beam Mass Spectrometry (MBMS) (Revised) (Fact Sheet)  

DOE Green Energy (OSTI)

This fact sheet provides information about Molecular Beam Mass Spectrometry (MBMS) capabilities and applications at NREL's National Bioenergy Center. NREL has six MBMS systems that researchers and industry partners can use to understand thermochemical biomass conversion and biomass composition recalcitrance.

Not Available

2011-07-01T23:59:59.000Z

40

Characterization of phenolic resins with thermogravimetry-mass spectrometry  

Science Conference Proceedings (OSTI)

As part of an advanced material research program, thermogravimetry-mass spectrometry (TG-MS) analysis of a phenolic resin was carried out recently for the study of the curing of the prepolymer, solvent extraction, and carbonization of the polymer at high temperature in inert atmosphere. These steps are critical to the quality of the produced advanced material. In addition to TG-MS, several other complementary techniques were also employed for the analysis of the phenolic resin prepolymer and its curing and thermal degradation products. These techniques include pyrolysis-gas chromatography-mass spectrometry, direct insertion probe-mass spectrometry and gas chromatography-mass spectrometry. 7 refs., 5 figs., 3 tabs.

Chang, Cherng; Tackett, J.R.

1990-01-01T23:59:59.000Z

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.


41

The power of mass spectrometry in the detection of fraud  

Science Conference Proceedings (OSTI)

Fraudulent products cost industry billions of dollars each year. Perfumes are a good example. The power of mass spectrometry in the detection of fraud Inform Magazine Analytical Chemistry Biochemistry Biotechnology Bert Poepping Fraudulent pro

42

Apparatus And Method For Hydrogen And Oxygen Mass Spectrometry...  

NLE Websites -- All DOE Office Websites (Extended Search)

Of The Terrestrial Magnetosphere A detector element for mass spectrometry of a flux of heavy and light ions. Available for thumbnail of Feynman Center (505) 665-9090 Email...

43

Laser desorption mass spectrometry for fast DNA analysis  

SciTech Connect

During the past few years, major effort has been directed toward developing mass spectrometry to measure biopolymers because of the great potential benefit to biomedical research. Hellenkamp and his co-workers were the first to report that large polypeptide molecules can be ionized and detected without significant fragmentation when a greater number of nicotinic acid molecules are used as a matrix. This method is now well known as matrix-assisted laser desorption/ionization (MALDI). Since then, various groups have reported measurements of very large proteins by MALDI. Reliable protein analysis by MALDI is more or less well established. However, the application of MALDI to nucleic acids analysis has been found to be much more difficult. Most research on the measurement of nucleic acid by MALDI were stimulated by the Human Genome Project. Up to now, the only method for reliable routine analysis of nucleic acid is gel electrophoresis. Different sizes of nucleic acids can be separated in gel medium when a high electric field is applied to the gel. However, the time needed to separate different sizes of DNA segments usually takes from several minutes to several hours. If MALDI can be successfully used for nucleic acids analysis, the analysis time can be reduced to less than I millisecond. In addition, no tagging with radioactive materials or chemical dyes is needed. In this work, we will review recent progress related to MALDI for DNA analysis.

Chen, C.H.; Ch`ang, L.Y.; Taranenko, N.I.; Allman, S.L.; Tang, K.; Matteson, K.J.

1995-09-01T23:59:59.000Z

44

Accelerator mass spectrometry as a bioanalytical tool for nutritional research  

SciTech Connect

Accelerator Mass Spectrometry is a mass spectrometric method of detecting long-lived radioisotopes without regard to their decay products or half-life. The technique is normally applied to geochronology, but recently has been developed for bioanalytical tracing. AMS detects isotope concentrations to parts per quadrillion, quantifying labeled biochemicals to attomole levels in milligram- sized samples. Its advantages over non-isotopeic and stable isotope labeling methods are reviewed and examples of analytical integrity, sensitivity, specificity, and applicability are provided.

Vogel, J.S.; Turteltaub, K.W.

1997-09-01T23:59:59.000Z

45

Single Cell Analysis Using Microfluidics Coupled to Ultrasensitive Mass Spectrometry  

NLE Websites -- All DOE Office Websites (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

46

Resonance Ionization Mass Spectrometry System for Measurement of Environmental Samples  

Science Conference Proceedings (OSTI)

A resonance ionization mass spectrometry (RIMS) system has been developed at the National Institute of Standards and Technology (NIST) for sensitive and selective determination of radio?cesium in the environment. The overall efficiency was determined to be 4×10?7 with a combined (laser and mass spectrometer) selectivity of 108 for both 135Cs and 137Cs with respect to 133Cs. RIMS isotopic ratio measurements of 135Cs/ 137Cs were performed on a nuclear fuel burn?up sample and compared to measurements on a similar system at Pacific Northwest National Laboratory (PNNL) and to conventional thermal ionization mass spectrometry (TIMS). Results of preliminary RIMS investigations on a freshwater lake sediment sample are also discussed.

L. Pibida; C. A. McMahon; W. Nörtershäuser; B. A. Bushaw

2002-01-01T23:59:59.000Z

47

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

48

Small system for tritium accelerator mass spectrometry  

DOE Patents (OSTI)

Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and .sup.3 He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

Roberts, Mark L. (Livermore, CA); Davis, Jay C. (Livermore, CA)

1993-01-01T23:59:59.000Z

49

Small system for tritium accelerator mass spectrometry  

DOE Patents (OSTI)

Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and [sup 3]He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

Roberts, M.L.; Davis, J.C.

1993-02-23T23:59:59.000Z

50

Small system for tritium accelerator mass spectrometry  

DOE Patents (OSTI)

This invention is comprised of an apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radiofrequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and {sup 3}He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

Roberts, M.L.; Davis, J.C.

1991-12-31T23:59:59.000Z

51

Chemical ionization tandem mass spectrometer for the in situ measurement of methyl hydrogen peroxide  

SciTech Connect

A new approach for measuring gas-phase methyl hydrogen peroxide [(MHP) CH{sub 3}OOH] utilizing chemical ionization mass spectrometry is presented. Tandem mass spectrometry is used to avoid mass interferences that hindered previous attempts to measure atmospheric CH{sub 3}OOH with CF{sub 3}O{sup -} clustering chemistry. CH{sub 3}OOH has been successfully measured in situ using this technique during both airborne and ground-based campaigns. The accuracy and precision for the MHP measurement are a function of water vapor mixing ratio. Typical precision at 500 pptv MHP and 100 ppmv H{sub 2}O is {+-}80 pptv (2 sigma) for a 1 s integration period. The accuracy at 100 ppmv H{sub 2}O is estimated to be better than {+-}40%. Chemical ionization tandem mass spectrometry shows considerable promise for the determination of in situ atmospheric trace gas mixing ratios where isobaric compounds or mass interferences impede accurate measurements.

St Clair, Jason M.; McCabe, David C. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125 (United States); Crounse, John D. [Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 (United States); Steiner, Urs [Varian, Inc., Santa Clara, California 95051 (United States); Wennberg, Paul O. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125 (United States); Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125 (United States)

2010-09-15T23:59:59.000Z

52

Fission Yield Measurements by Inductively Coupled Plasma Mass-Spectrometry  

SciTech Connect

Correct prediction of the fission products inventory in irradiated nuclear fuels is essential for accurate estimation of fuel burnup, establishing proper requirements for spent fuel transportation and storage, materials accountability and nuclear forensics. Such prediction is impossible without accurate knowledge of neutron induced fission yields. Unfortunately, the accuracy of the fission yields reported in the ENDF/B-VII.0 library is not uniform across all of the data and much of the improvement is desired for certain isotopes and fission products. We discuss our measurements of cumulative fission yields in nuclear fuels irradiated in thermal and fast reactor spectra using Inductively Coupled Plasma Mass Spectrometry.

Irina Glagolenko; Bruce Hilton; Jeffrey Giglio; Daniel Cummings; Karl Grimm; Richard McKnight

2009-11-01T23:59:59.000Z

53

LC-IMS-MS Feature Finder: Detecting Multidimensional Liquid Chromatography, Ion Mobility, and Mass Spectrometry Features in Complex Datasets  

SciTech Connect

We introduce a command line software application LC-IMS-MS Feature Finder that searches for molecular ion signatures in multidimensional liquid chromatography-ion mobility spectrometry-mass spectrometry (LC-IMS-MS) data by clustering deisotoped peaks with similar monoisotopic mass, charge state, LC elution time, and ion mobility drift time values. The software application includes an algorithm for detecting and quantifying co-eluting chemical species, including species that exist in multiple conformations that may have been separated in the IMS dimension.

Crowell, Kevin L.; Slysz, Gordon W.; Baker, Erin Shammel; Lamarche, Brian L.; Monroe, Matthew E.; Ibrahim, Yehia M.; Payne, Samuel H.; Anderson, Gordon A.; Smith, Richard D.

2013-09-13T23:59:59.000Z

54

Coal liquefaction process streams characterization and evaluation. Characterization of coal-derived materials by field desorption mass spectrometry, two-dimensional nuclear magnetic resonance, supercritical fluid extraction, and supercritical fluid chromatography/mass spectrometry  

SciTech Connect

Under contract from the DOE , and in association with CONSOL Inc., Battelle, Pacific Northwest Laboratory (PNL) evaluated four principal and several complementary techniques for the analysis of non-distillable direct coal liquefaction materials in support of process development. Field desorption mass spectrometry (FDMS) and nuclear magnetic resonance (NMR) spectroscopic methods were examined for potential usefulness as techniques to elucidate the chemical structure of residual (nondistillable) direct coal liquefaction derived materials. Supercritical fluid extraction (SFE) and supercritical fluid chromatography/mass spectrometry (SFC/MS) were evaluated for effectiveness in compound-class separation and identification of residual materials. Liquid chromatography (including microcolumn) separation techniques, gas chromatography/mass spectrometry (GC/MS), mass spectrometry/mass spectrometry (MS/MS), and GC/Fourier transform infrared (FTIR) spectroscopy methods were applied to supercritical fluid extracts. The full report authored by the PNL researchers is presented here. The following assessment briefly highlights the major findings of the project, and evaluates the potential of the methods for application to coal liquefaction materials. These results will be incorporated by CONSOL into a general overview of the application of novel analytical techniques to coal-derived materials at the conclusion of CONSOL`s contract.

Campbell, J.A.; Linehan, J.C.; Robins, W.H. [Battelle Pacific Northwest Lab., Richland, WA (United States)

1992-07-01T23:59:59.000Z

55

Conditioning of ion sources for mass spectrometry of plasmas  

DOE Green Energy (OSTI)

Mass spectrometry is a useful diagnostic technique for monitoring plasma species and plasma-surface interactions. In order to maximize the sensitivity of measurements of hydrogen-fueled fusion plasmas or hydrogen-based discharge cleaning and etching plasmas, the ion sources of mass spectrometers are operated at or near the high pressure limit of 10/sup -4/ Torr (10/sup -2/ Pa). Such high ambient pressures of hydrogen give rise to high background levels of residual gases such as H/sub 2/O, CO, and CH/sub 4/, due to surface reactions on the ion source electrodes. For a commonly used ion source configuration, the residual gas production is a linear function of the ambient H/sub 2/ pressure. Hydrogen conditioning can reduce the absolute residual gas levels. Steady-state residual gas production is observed in a conditioned ion source, which is related to a balance of diffusion and sorption on the electrode surfaces.

Dylla, H.F.; Blanchard, W.R.

1983-02-01T23:59:59.000Z

56

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

57

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

58

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

59

Instrumentation development for coupling ion/ion reactions and ion mobility in biological mass spectrometry.  

E-Print Network (OSTI)

??The development of mass spectrometry (MS) instrumentation for novel biological applications, specifically, the development of instrumentation that integrates ion/ion reaction capabilities in an ion trap… (more)

Soyk, Matthew William

2008-01-01T23:59:59.000Z

60

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

SciTech Connect

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

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

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

Office of Science (SC) Website

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...

62

Method for predicting peptide detection in mass spectrometry  

SciTech Connect

A method of predicting whether a peptide present in a biological sample will be detected by analysis with a mass spectrometer. The method uses at least one mass spectrometer to perform repeated analysis of a sample containing peptides from proteins with known amino acids. The method then generates a data set of peptides identified as contained within the sample by the repeated analysis. The method then calculates the probability that a specific peptide in the data set was detected in the repeated analysis. The method then creates a plurality of vectors, where each vector has a plurality of dimensions, and each dimension represents a property of one or more of the amino acids present in each peptide and adjacent peptides in the data set. Using these vectors, the method then generates an algorithm from the plurality of vectors and the calculated probabilities that specific peptides in the data set were detected in the repeated analysis. The algorithm is thus capable of calculating the probability that a hypothetical peptide represented as a vector will be detected by a mass spectrometry based proteomic platform, given that the peptide is present in a sample introduced into a mass spectrometer.

Kangas, Lars [West Richland, WA; Smith, Richard D [Richland, WA; Petritis, Konstantinos [Richland, WA

2010-07-13T23:59:59.000Z

63

Chemical Ionization Mass Spectrometer (CIMS) Shanhu Lee, Kent State University (http://www.personal.kent.edu/~slee19/)  

E-Print Network (OSTI)

Chemical Ionization Mass Spectrometer (CIMS) Shanhu Lee, Kent State University (http ionization mass spectrometry (PTR-CIMS). A typical CIMS instrument can be constructed from an ion source, an ion molecular reactor, and a quadrupole mass spectrometer. Shown below is schematic diagram of a CIMS

Lee, Shan-Hu

64

Structural determination of intact proteins using mass spectrometry  

DOE Patents (OSTI)

The present invention relates to novel methods of determining the sequence and structure of proteins. Specifically, the present invention allows for the analysis of intact proteins within a mass spectrometer. Therefore, preparatory separations need not be performed prior to introducing a protein sample into the mass spectrometer. Also disclosed herein are new instrumental developments for enhancing the signal from the desired modified proteins, methods for producing controlled protein fragments in the mass spectrometer, eliminating complex microseparations, and protein preparatory chemical steps necessary for cross-linking based protein structure determination.Additionally, the preferred method of the present invention involves the determination of protein structures utilizing a top-down analysis of protein structures to search for covalent modifications. In the preferred method, intact proteins are ionized and fragmented within the mass spectrometer.

Kruppa, Gary (San Francisco, CA); Schoeniger, Joseph S. (Oakland, CA); Young, Malin M. (Livermore, CA)

2008-05-06T23:59:59.000Z

65

Characterization of Individual Nanoparticles and Applications of Nanoparticles in Mass Spectrometry  

E-Print Network (OSTI)

The chemical characterization of individual nanoparticles (NPs) mass spectrometry (SIMS) technique are Au4004+ and C60+. The ionized ejecta from each impact are recorded individually which allows to identify ions emitted from a surface volume of ~10 nm in diameter and 5-10 nm in depth. The mode of analyzing ejecta individually from each single cluster impact gives insight into surface homogeneity, in our case NPs and their immediate surroundings. We show that when the NPs (50 nm Al) are larger than the size of the volume perturbed by the projectile, the secondary ion emission (SI) resembles that of a bulk surface. However, when the NP (5 nm Ag) is of the size range of the volume perturbed by projectile the SI emission is different from that of a bulk surface. As part of this sub-assay volume study, the influence of neighboring NP on the SI emission was examined by using a mixture of different types of NPs (5 nm Au and 5 nm Ag). The methodology of using cluster SIMS via a sequence of stochastic single impacts yield information on the surface coverage of the NPs, as well as the influence of the chemical environment on the type of SI emission. We also present a case of soft landing NPs for laser desorption ionization mass spectrometry. NPs enhance the SI emission in a manner that maintains the integrity of the spatial distribution of molecular species. The results indicate that the application can be extended to imaging mass spectrometry.

Rajagopal Achary, Sidhartha Raja

2010-05-01T23:59:59.000Z

66

Mass Spectrometry for Translational Proteomics: Progress and Clinical Implications  

SciTech Connect

Mass spectrometry (MS)-based proteomics measurements have become increasingly utilized in a wide range of biological and biomedical applications, and have significantly enhanced the understanding of the complex and dynamic nature of the proteome and its connections to biology and diseases. While some MS techniques such as those for targeted analysis are increasingly applied with great success, others such as global quantitative analysis (for e.g. biomarker discovery) are more challenging and continue to be developed and refined to provide the desired throughput, sensitivity and/ or specificity. New MS capabilities and proteomics-based pipelines/strategies also keep enhancing for the advancement of clinical proteomics applications such as protein biomarker discovery and validation. Herein, we provide a brief review to summarize the current state of MS-based proteomics with respect to its advantages and present limitations, while highlighting its potential in future clinical applications.

Baker, Erin Shammel; Liu, Tao; Petyuk, Vladislav A.; Burnum-Johnson, Kristin E.; Ibrahim, Yehia M.; Anderson, Gordon A.; Smith, Richard D.

2012-08-31T23:59:59.000Z

67

Toward laser ablation Accelerator Mass Spectrometry of actinides  

Science Conference Proceedings (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

68

Study of Electrochemical Reactions Using Nanospray Desorption Electrospray Ionization Mass Spectrometry  

Science Conference Proceedings (OSTI)

The combination of electrochemistry (EC) and mass spectrometry (MS) is a powerful analytical tool for studying mechanisms of redox reactions, identification of products and intermediates, and online derivatization/recognition of analytes. This work reports a new coupling interface for EC/MS by employing nanospray desorption electrospray ionization (nano-DESI), a recently developed ambient ionization method. We demonstrate online coupling of nano-DESI-MS with a traditional electrochemical flow cell, in which the electrolyzed solution emanating from the cell is ionized by nano-DESI for MS analysis. Furthermore, we show first coupling of nano-DESI-MS with an interdigitated array (IDA) electrode enabling chemical analysis of electrolyzed samples directly from electrode surfaces. Because of its inherent sensitivity, nano-DESI enables chemical analysis of small volumes and concentrations of sample solution. Specifically, good-quality signal of dopamine and its oxidized form, dopamine ortho-quinone, was obtained using 10 {mu}L of 1 {mu}M solution of dopamine on the IDA. Oxidation of dopamine, reduction of benzodiazepines, and electrochemical derivatization of thiol groups were used to demonstrate the performance of the technique. Our results show the potential of nano-DESI as a novel interface for electrochemical mass spectrometry research.

Liu, Pengyuan; Lanekoff, Ingela T.; Laskin, Julia; Dewald, Howard D.; Chen, Hao

2012-07-03T23:59:59.000Z

69

The Multiplexed Chemical Kinetic Photoionization Mass Spectrometer: A New Approach To Isomer-resolved Chemical Kinetics  

E-Print Network (OSTI)

instruments applied to analysis of complex chemical mixturesrelies on chemical separation (by chromatography) into pureThe multiplexed chemical kinetic photoionization mass

Osborne, David L.

2009-01-01T23:59:59.000Z

70

Molecular Characterization of Nitrogen Containing Organic Compounds in Biomass Burning Aerosols Using High Resolution Mass Spectrometry  

DOE Green Energy (OSTI)

Although nitrogen-containing organic compounds (NOC) are important components of atmospheric aerosols, little is known about their chemical compositions. Here we present detailed characterization of the NOC constituents of biomass burning aerosol (BBA) samples using high resolution electrospray ionization mass spectrometry (ESI/MS). Accurate mass measurements combined with MS/MS fragmentation experiments of selected ions were used to assign molecular structures to individual NOC species. Our results indicate that N-heterocyclic alkaloid compounds - species naturally produced by plants and living organisms - comprise a substantial fraction of NOC in BBA samples collected from test burns of five biomass fuels. High abundance of alkaloids in test burns of ponderosa pine - a widespread tree in the western U.S. areas frequently affected by large scale fires - suggests that N-heterocyclic alkaloids in BBA can play a significant role in dry and wet deposition of fixed nitrogen in this region.

Laskin, Alexander; Smith, Jeffrey S.; Laskin, Julia

2009-05-13T23:59:59.000Z

71

Proteomics by FTICR Mass Spectrometry: Top Down and Bottom Up  

SciTech Connect

This review offers a broad overview of recent FTICR applications and technological developments in the field of proteomics, directed to a variety of people with different expertise and interests. Both the ''bottom-up'' (peptide level) and ''top-down'' (intact protein level) approaches will be covered and various related aspects will be discussed and illustrated with examples that are among the best available references in the literature. ''Bottom-up topics include peptide fragmentation, the AMT approach and DREAMS technology, quantitative proteomics, post-translational modifications, and special FTICR software focused on peptide and protein identification. Topics in the ''top-down'' part include various aspects of high-mass measurements, protein tandem mass spectrometry, protein confirmations, protein-protein complexes, as well as some esoteric applications that may become more practical in the coming years. Finally, examples of integrating both approaches and medical proteomics applications using FTICR will be provided, closing with an outlook of what may be coming our way sooner than later.

Bogdanov, Bogdan; Smith, Richard D.

2005-03-31T23:59:59.000Z

72

Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio.  

SciTech Connect

Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of {sup 14}C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of {sup 14}C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the {sup 14}C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with {sup 14}C corresponds to 30 fg equivalents. AMS provides an sensitive, accurate and precise method of measuring drug compounds in biological matrices.

Keck, B D; Ognibene, T; Vogel, J S

2010-02-05T23:59:59.000Z

73

Transition of Iodine Analysis to Accelerator Mass Spectrometry  

SciTech Connect

Funding was received from NA-22 to investigate transitioning iodine isotopic analyses to an accelerator mass spectrometry (AMS) system. The present method uses gas-phase chemistry followed by thermal ionization mass spectrometry (TIMS). It was anticipated that the AMS approach could provide comparable data, with improved background levels and superior sample throughput. An aqueous extraction method was developed for removal of iodine species from high-volume air filters. Ethanol and sodium hydroxide, plus heating and ultrasonic treatment, were used to successfully extract iodine from loaded high-volume air filters. Portions of the same filters were also processed in the traditional method and analyzed by TIMS for comparison. Aliquot parts of the aqueous extracts were analyzed by AMS at the Swiss Federal Institute of Technology. Idaho National Laboratory (INL) personnel visited several AMS laboratories in the US, Spain, and Switzerland. Experience with AMS systems from several manufacturers was gained, and relationships were developed with key personnel at the laboratories. Three batches of samples were analyzed in Switzerland, and one in Spain. Results show that the INL extraction method successfully extracted enough iodine from high-volume air filters to allow AMS analysis. Comparison of the AMS and TIMS data is very encouraging; while the TIMS showed about forty percent more atoms of 129I, the 129/127 ratios tracked each other very well between the two methods. The time required for analysis is greatly reduced for the aqueous extraction/AMS approach. For a hypothetical batch of thirty samples, the AMS methodology is about five 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 for TIMS. This results from the fundamental mechanisms of ionization in the AMS system and cleanup of molecular interferences. We showed that an aqueous 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.

J. E. Delmore

2010-09-01T23:59:59.000Z

74

Extension of the Focusable Mass Range in Distance-of-Flight Mass Spectrometry with Multiple Detectors  

SciTech Connect

Since the underlying theory of Distance-of-Flight Mass Spectrometry (DOFMS) was reported in 2007,[1] laboratory results[2, 3] have proven its practical viability. However, these previous implementations of DOFMS considered ion detection only over narrow DOF-detection windows, with 25-mm being the greatest detection length explored. These small mass windows cannot be used to evaluate how DOFMS focusing performs over greater DOF detection lengths and mass ranges. In the present study, we expand on previous studies by placing two spatially selective ion detectors along the detection plane of the DOFMS instrument. Ion signals are simultaneously collected from both DOF detectors in order to simulate DOFMS performance with a longer spatially selective ion detector.

Gundlach-Graham, Alexander W.; Dennis, Elise; Ray, Steven J.; Enke, Christie G.; Carado, Anthony J.; Barinaga, Charles J.; Koppenaal, David W.; Hieftje, Gary M.

2012-11-15T23:59:59.000Z

75

230Th-234U Age-Dating Uranium by Mass Spectrometry  

Science Conference Proceedings (OSTI)

This is the standard operating procedure used by the Isotope Ratio Mass Spectrometry Group of the Chemical Sciences Division at LLNL for the preparation of a sample of uranium oxide or uranium metal for {sup 230}Th-{sup 234}U age-dating. The method described here includes the dissolution of a sample of uranium oxide or uranium metal, preparation of a secondary dilution, spiking of separate aliquots for uranium and thorium isotope dilution measurements, and purification of uranium and thorium aliquots for mass spectrometry. This SOP may be applied to uranium samples of unknown purity as in a nuclear forensic investigation, and also to well-characterized samples such as, for example, U{sub 3}O{sub 8} and U-metal certified reference materials. The sample of uranium is transferred to a quartz or PFA vial, concentrated nitric acid is added and the sample is heated on a hotplate at approximately 100 C for several hours until it dissolves. The sample solution is diluted with water to make the solution approximately 4 M HNO{sub 3} and hydrofluoric acid is added to make it 0.05 M HF. A secondary dilution of the primary uranium solution is prepared. Separate aliquots for uranium and thorium isotope dilution measurements are taken and spiked with {sup 233}U and {sup 229}Th, respectively. The spiked aliquot for uranium isotope dilution analysis is purified using EiChrom UTEVA resin. The spiked aliquot for thorium isotope dilution analysis is purified by, first, a 1.8 mL AG1x8 resin bed in 9 M HCl on which U adsorbs and Th passes through; second, adsorbing Th on a 1 mL AG1x8 resin bed in 8 M HNO{sub 3} and then eluting it with 9 M HCl followed by 0.1 M HCl + 0.005 M HF; and third, by passing the Th through a final 1.0 mL AG1x8 resin bed in 9 M HCl. The mass spectrometry is performed using the procedure 'Th and U Mass Spectrometry for {sup 230}Th-{sup 234}U Age Dating'.

Williams, R W; Gaffney, A M

2012-04-18T23:59:59.000Z

76

Molecular Characterization of Biomass Burning Aerosols Using High Resolution Mass Spectrometry  

DOE Green Energy (OSTI)

Chemical characterizations of atmospheric aerosols is a serious analytical challenge because of the complexity of particulate matter analyte composed of a large number of compounds with a wide range of molecular structures, physico-chemical properties, and reactivity. In this study chemical composition of biomass burning organic aerosol (BBOA) samples is characterized by high resolution electrospray ionization mass spectrometry (ESI/MS). Accurate mass measurement combined with Kendrick analysis allowed us to assign elemental composition for hundreds of compounds in the range of m/z values of 50-1000. ESI/MS spectra of different BBOA samples contain a variety of distinct, sample specific, characteristic peaks that can be used as unique markers for different types of biofuels. Our results indicate that a significant number of high-MW organic compounds in BBOA samples are highly oxidized polar species that can be efficiently detected using ESI/MS but are difficult to observe using the conventional GCMS analysis of aerosol samples. The average O:C ratios obtained for each of the BBOA samples studied in this work are in a strikingly good agreement with the previously reported values obtained using STXM/NEXAFS. The degree of unsaturation of detected organic compounds shows a clear decrease with increase in the molecular weight of the anyalyte molecules. The decrease is particularly pronounced for the samples containing a large number of CH2-based homologous series.

Smith, Jeffrey S.; Laskin, Alexander; Laskin, Julia

2009-02-13T23:59:59.000Z

77

CNT-based gas ionizers with integrated MEMS gate for portable mass spectrometry applications  

E-Print Network (OSTI)

We report the fabrication and experimental characterization of a novel low-cost carbon nanotube (CNT)-based electron impact ionizer (EII) with integrated gate for portable mass spectrometry applications. The device achieves ...

Velasquez-Garcia, Luis Fernando

78

CNT-based MEMS/NEMS gas ionizers for portable mass spectrometry applications  

E-Print Network (OSTI)

We report the fabrication and experimental characterization of a carbon nanotube (CNT)-based MEMS/NEMS electron impact gas ionizer with an integrated extractor gate for portable mass spectrometry. The ionizer achieves ...

Velasquez-Heller, Luis Fernand

79

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)

80

Fractal morphology, imaging and mass spectrometry of single aerosol particles in flight  

DOE Data Explorer (OSTI)

This deposition includes the aerosol diffraction images used for phasing, fractal morphology, and time-of-flight mass spectrometry. Files in this deposition are ordered in subdirectories that reflect the specifics.

Loh, N. Duane

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

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.

82

Nucleon Mass Splitting at Finite Isospin Chemical Potential  

E-Print Network (OSTI)

We investigate nucleon mass splitting at finite isospin chemical potential in the frame of two flavor Nambu--Jona-Lasinio model. It is analytically proved that, in the phase with explicit isospin symmetry breaking the proton mass decreases and the neutron mass increases linearly in the isospin chemical potential.

Sheng Chang; Jifeng Liu; Pengfei Zhuang

2007-02-09T23:59:59.000Z

83

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

Science Conference Proceedings (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

84

Comparative proteogenomics: combining mass spectrometry and comparative genomics to analyze multiple genomes  

SciTech Connect

While bacterial genome annotations have significantly improved in recent years, techniques for bacterial proteome annotation (including post-translational chemical modifications, signal peptides, proteolytic events, etc.) are still in their infancy. At the same time, the number of sequenced bacterial genomes is rising sharply, far outpacing our ability to validate the predicted genes, let alone annotate bacterial proteomes. In this study, we use tandem mass spectrometry (MS/MS) to annotate the proteome of Shewanella oneidensis MR-1, an important microbe for bioremediation. In particular, we provide the first comprehensive map of post-translational modifications in a bacterial genome, including a large number of chemical modifications, signal peptide cleavages and cleavage of N-terminal methionine residues. We also detect multiple genes that were missed or assigned incorrect start positions by gene prediction programs and suggest corrections to improve the gene annotation. This study demonstrates that complementing every genome sequencing project by an MS/MS project would significantly improve both genome and proteome annotations for a reasonable cost.

Gupta, Nitin; Benhamida, Jamal; Bhargava, Vipul; Goodman, Daniel; Kain , Elisabeth; Kerman, Ian; Nguyen , Ngan; Ollikainen, Noah; Rodriguez, Jesse; Wang, J.; Lipton, Mary S.; Romine, Margaret F.; Bafna, Vineet; Smith, Richard D.; Pevzner, Pavel A.

2008-07-30T23:59:59.000Z

85

Multivariate analysis of progressive thermal desorption coupled gas chromatography-mass spectrometry.  

SciTech Connect

Thermal decomposition of poly dimethyl siloxane compounds, Sylgard{reg_sign} 184 and 186, were examined using thermal desorption coupled gas chromatography-mass spectrometry (TD/GC-MS) and multivariate analysis. This work describes a method of producing multiway data using a stepped thermal desorption. The technique involves sequentially heating a sample of the material of interest with subsequent analysis in a commercial GC/MS system. The decomposition chromatograms were analyzed using multivariate analysis tools including principal component analysis (PCA), factor rotation employing the varimax criterion, and multivariate curve resolution. The results of the analysis show seven components related to offgassing of various fractions of siloxanes that vary as a function of temperature. Thermal desorption coupled with gas chromatography-mass spectrometry (TD/GC-MS) is a powerful analytical technique for analyzing chemical mixtures. It has great potential in numerous analytic areas including materials analysis, sports medicine, in the detection of designer drugs; and biological research for metabolomics. Data analysis is complicated, far from automated and can result in high false positive or false negative rates. We have demonstrated a step-wise TD/GC-MS technique that removes more volatile compounds from a sample before extracting the less volatile compounds. This creates an additional dimension of separation before the GC column, while simultaneously generating three-way data. Sandia's proven multivariate analysis methods, when applied to these data, have several advantages over current commercial options. It also has demonstrated potential for success in finding and enabling identification of trace compounds. Several challenges remain, however, including understanding the sources of noise in the data, outlier detection, improving the data pretreatment and analysis methods, developing a software tool for ease of use by the chemist, and demonstrating our belief that this multivariate analysis will enable superior differentiation capabilities. In addition, noise and system artifacts challenge the analysis of GC-MS data collected on lower cost equipment, ubiquitous in commercial laboratories. This research has the potential to affect many areas of analytical chemistry including materials analysis, medical testing, and environmental surveillance. It could also provide a method to measure adsorption parameters for chemical interactions on various surfaces by measuring desorption as a function of temperature for mixtures. We have presented results of a novel method for examining offgas products of a common PDMS material. Our method involves utilizing a stepped TD/GC-MS data acquisition scheme that may be almost totally automated, coupled with multivariate analysis schemes. This method of data generation and analysis can be applied to a number of materials aging and thermal degradation studies.

Van Benthem, Mark Hilary; Mowry, Curtis Dale; Kotula, Paul Gabriel; Borek, Theodore Thaddeus, III

2010-09-01T23:59:59.000Z

86

Reflection mass spectrometry technique for monitoring and controlling composition during molecular beam epitaxy  

DOE Patents (OSTI)

This invention is comprised of a method for on-line accurate monitoring and precise control of molecular beam epitaxial growth of Groups III-III-V or Groups III-V-V layers in an advanced semiconductor device incorporates reflection mass spectrometry. The reflection mass spectrometry is responsive to intentional perturbations in molecular fluxes incident on a substrate by accurately measuring the molecular fluxes reflected from the substrate. The reflected flux is extremely sensitive to the state of the growing surface and the measurements obtained enable control of newly forming surfaces that are dynamically changing as a result of growth.

Brennan, T.M.; Hammons, B.E.; Tsao, J.Y.

1990-08-15T23:59:59.000Z

87

Reflection mass spectrometry technique for monitoring and controlling composition during molecular beam epitaxy  

DOE Patents (OSTI)

A method for on-line accurate monitoring and precise control of molecular beam epitaxial growth of Groups III-III-V or Groups III-V-V layers in an advanced semiconductor device incorporates reflection mass spectrometry. The reflection mass spectrometry is responsive to intentional perturbations in molecular fluxes incident on a substrate by accurately measuring the molecular fluxes reflected from the substrate. The reflected flux is extremely sensitive to the state of the growing surface and the measurements obtained enable control of newly forming surfaces that are dynamically changing as a result of growth.

Brennan, Thomas M. (Albuquerque, NM); Hammons, B. Eugene (Tijeras, NM); Tsao, Jeffrey Y. (Albuquerque, NM)

1992-01-01T23:59:59.000Z

88

Noise reduction in negative-ion quadrupole mass spectrometry  

DOE Patents (OSTI)

This invention is comprised of 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, P.

1991-12-31T23:59:59.000Z

89

Apparatus for preparing a sample for mass spectrometry  

DOE Patents (OSTI)

Disclosed is an apparatus 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.

Villa-Aleman, E.

1992-12-31T23:59:59.000Z

90

International Journal of Mass Spectrometry 291 (2010) 108117 Contents lists available at ScienceDirect  

E-Print Network (OSTI)

Direct International Journal of Mass Spectrometry journal homepage: www.elsevier.com/locate/ijms Detection of radiation-exposure Keywords: Metabolomic Radiation exposure DMS Ion mobility Electrospray a b s t r a c t Technology to enable rapid screening for radiation exposure has been identified as an important need, and, as a part of a NIH

Brenner, David Jonathan

91

Dynamic mass spectrometry: a residual gas analysis method and some applications  

SciTech Connect

Dynamic mass spectrometry is a unique method of residual gas analysis used to monitor and trouble-shoot industrial vacuum process operations. This discussion presents applications and results of the method, and describes the equipment and analytical method developed at Rocky Flats to perform this work. GHT)

McFeeters, T.L.

1981-01-01T23:59:59.000Z

92

Spatially resolved thermal desorption/ionization coupled with mass spectrometry  

DOE Patents (OSTI)

A system and method for sub-micron analysis of a chemical composition of a specimen are described. The method includes providing a specimen for evaluation and a thermal desorption probe, thermally desorbing an analyte from a target site of said specimen using the thermally active tip to form a gaseous analyte, ionizing the gaseous analyte to form an ionized analyte, and analyzing a chemical composition of the ionized analyte. The thermally desorbing step can include heating said thermally active tip to above 200.degree. C., and positioning the target site and the thermally active tip such that the heating step forms the gaseous analyte. The thermal desorption probe can include a thermally active tip extending from a cantilever body and an apex of the thermally active tip can have a radius of 250 nm or less.

Jesse, Stephen; Van Berkel, Gary J; Ovchinnikova, Olga S

2013-02-26T23:59:59.000Z

93

Photon burst mass spectrometry--ultrasensitive detection of rare isotopes  

SciTech Connect

Progress is reported on the development of a new technique for measurement of trace levels of radioisotopes which is based on fluorescence detection of output from a mass spectrometer. Significant achievements include the observation of fluorescence and burst signals from Kr isotopes, including enriched samples of {sup 85}Kr with a 4-collector system. An abundance sensitivity is demonstrated with {sup 83}Kr and {sup 85}Kr.

Hansen, C.S.; Pan, X.J.; Fairbank, W.M. Jr. [Colorado State Univ., Fort Collins, CO (United States). Physics Dept.; Oona, H.; Chamberlin, E.P.; Nogar, N.S.; Fearey, B.L. [Los Alamos National Lab., NM (United States)

1995-02-01T23:59:59.000Z

94

Ion source for high-precision mass spectrometry  

DOE Patents (OSTI)

The invention is directed to a method for increasing the precision of positive-ion relative abundance measurements conducted in a sector mass spectrometer having an ion source for directing a beam of positive ions onto a collimating slit. The method comprises incorporating in the source an electrostatic lens assembly for providing a positive-ion beam of circular cross section for collimation by the slit.

Todd, Peter J. (Oak Ridge, TN); McKown, Henry S. (Oak Ridge, TN); Smith, David H. (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

95

Inductively Coupled Plasma Mass Spectrometry Uranium Error Propagation  

SciTech Connect

The Hazards Control Department at Lawrence Livermore National Laboratory (LLNL) uses Inductively Coupled Plasma Mass Spectrometer (ICP/MS) technology to analyze uranium in urine. The ICP/MS used by the Hazards Control Department is a Perkin-Elmer Elan 6000 ICP/MS. The Department of Energy Laboratory Accreditation Program requires that the total error be assessed for bioassay measurements. A previous evaluation of the errors associated with the ICP/MS measurement of uranium demonstrated a {+-} 9.6% error in the range of 0.01 to 0.02 {micro}g/l. However, the propagation of total error for concentrations above and below this level have heretofore been undetermined. This document is an evaluation of the errors associated with the current LLNL ICP/MS method for a more expanded range of uranium concentrations.

Hickman, D P; Maclean, S; Shepley, D; Shaw, R K

2001-07-01T23:59:59.000Z

96

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

97

{sup 99}Tc bioassay by inductively coupled plasma mass spectrometry (ICP-MS)  

Science Conference Proceedings (OSTI)

A means of analyzing {sup 99}Tc in urine by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. Historically, {sup 99}Tc analysis was based on the radiometric detection of the 293 keV E{sub Max} beta decay product by liquid scintillation or gas flow proportional counting. In a urine matrix, the analysis of{sup 99}Tc is plagued with many difficulties using conventional radiometric methods. Difficulties originate during chemical separation due to the volatile nature of Tc{sub 2}O{sub 7} or during radiation detection due to color or chemical quenching. A separation scheme for {sup 99}Tc detection by ICP-MS is given and is proven to be a sensitive and robust analytical alternative. A comparison of methods using radiometric and mass quantitation of {sup 99}Tc has been conducted in water, artificial urine, and real urine matrices at activity levels between 700 and 2,200 dpm/L. Liquid scintillation results based on an external standard quench correction and a quench curve correction method are compared to results obtained by ICP-MS. Each method produced accurate results, however the precision of the ICP-MS results is superior to that of liquid scintillation results. Limits of detection (LOD) for ICP-MS and liquid scintillation detection are 14.67 and 203.4 dpm/L, respectively, in a real urine matrix. In order to determine the basis for the increased precision of the ICP-MS results, the detection sensitivity for each method is derived and measured. The detection sensitivity for the {sup 99}Tc isotope by ICP-MS is 2.175 x 10{sup {minus}7} {+-} 8.990 x 10{sup {minus}9} and by liquid scintillation is 7.434 x 10{sup {minus}14} {+-} 7.461 x 10{sup {minus}15}. A difference by seven orders of magnitude between the two detection systems allows ICP-MS samples to be analyzed for a period of 15 s compared to 3,600 s by liquid scintillation counting with a lower LOD.

Lewis, L.A.

1998-05-01T23:59:59.000Z

98

Quantitative Analysis of Tetramethylenedisulfotetramine ("Tetramine") Spiked into Beverages by Liquid Chromatography Tandem Mass Spectrometry with Validation by Gas Chromatography Mass Spectrometry  

Science Conference Proceedings (OSTI)

Tetramethylenedisulfotetramine, commonly known as tetramine, is a highly neurotoxic rodenticide (human oral LD{sub 50} = 0.1 mg/kg) used in hundreds of deliberate food poisoning events in China. Here we describe a method for quantitation of tetramine spiked into beverages, including milk, juice, tea, cola, and water and cleaned up by C8 solid phase extraction and liquid-liquid extraction. Quantitation by high performance liquid chromatography tandem mass spectrometry (LC/MS/MS) was based upon fragmentation of m/z 347 to m/z 268. The method was validated by gas chromatography mass spectrometry (GC/MS) operated in SIM mode for ions m/z 212, 240, and 360. The limit of quantitation was 0.10 {micro}g/mL by LC/MS/MS versus 0.15 {micro}g/mL for GC/MS. Fortifications of the beverages at 2.5 {micro}g/mL and 0.25 {micro}g/mL were recovered ranging from 73-128% by liquid-liquid extraction for GC/MS analysis, 13-96% by SPE and 10-101% by liquid-liquid extraction for LC/MS/MS analysis.

Owens, J; Hok, S; Alcaraz, A; Koester, C

2008-11-13T23:59:59.000Z

99

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

NLE Websites -- All DOE Office Websites (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

100

Tandem mass spectrometry for characterization of high-carbon-number geoporphyrins  

Science Conference Proceedings (OSTI)

Geoporphyrins are separated into TCL fractions after being isolated from Boscan oil (West Venezuela) by column chromatography. Analysis of each fraction by electron ionization mass spectrometry identified the porphyrin classes present and their carbon number ranges, but the spectra were extremely complex. Tandem mass spectrometry (MS/MS) allowed selection of molecular ions of individual carbon number porphyrins of the DPEP and etio types for fragmentation by collisionally activated dissociation. Comparison of their daughter and neutral loss spectra with those of porphyrin standards provided the first structural information on individual high-carbon-number geoporphyrins (>C/sub 33/). This information is helpful in the study of their geologic evolution and suggests the potential for using MS/MS data on high-carbon-number geoporphyrins as a parameter in oil exploration. Metalated and demetalated porphyrins of the same carbon number produced similar spectra, suggesting that samples may require less treatment for analysis by MS/MS than by conventional MS.

Johnson, J.V.; Britton, E.D.; Yost, R.A.; Quirke, J.M.E.; Cuesta, L.L.

1986-06-01T23:59:59.000Z

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.


101

B American Society for Mass Spectrometry( 2011 DOI: 10.1007/s13361-011-0179-8  

E-Print Network (OSTI)

A new instrument that combines ion mobility spectrometry (IMS) separations with tandem mass spectrometry in the mobility dimension. Here, we report the development of a new instrument that combines mobility separations Spectrom. (2011) 22:1477Y1485 RESEARCH ARTICLE An Ion Mobility/Ion Trap/Photodissociation Instrument

Clemmer, David E.

102

Compositional Analysis of the High Molecular Weight Ethylene Oxide Propylene Oxide Copolymer by MALDI Mass Spectrometry  

E-Print Network (OSTI)

The composition of narrow distribution poly ethylene oxide-propylene oxide copolymer (Mw ~ 8700 Da) was studied using matrix assisted laser desorption ionization (MALDI) mass spectrometry. The ethylene oxide-propylene oxide copolymer produced oligomers separated by 14 Da. The average resolving power over the entire spectrum was 28,000. Approximately 448 isotopically resolved peaks representing about 56 oligomers are identified. Although agreement between experimental and calculated isotopic distributions was strong, the compositional assignment was difficult. This is due to the large number of possible isobaric components. The purpose of this research is to resolve and study the composition of high mass copolymer such as ethylene oxide-propylene oxide.

Houshia, Orwa Jaber

2012-01-01T23:59:59.000Z

103

Modern Methods for Lipid AnalysisChapter 11 Analysis of Steroids by Liquid Chromatography — Atmospheric Pressure Photoionization Mass Spectrometry  

Science Conference Proceedings (OSTI)

Modern Methods for Lipid Analysis Chapter 11 Analysis of Steroids by Liquid Chromatography — Atmospheric Pressure Photoionization Mass Spectrometry Methods and Analyses eChapters Methods - Analyses Books 7B3610598EB68717295AAD02DBA4F828

104

Modern Methods for Lipid AnalysisChapter 4 Liquid Chromatography/Electrospray Ionization Mass Spectrometry for Analysis of Oxidized Lipids  

Science Conference Proceedings (OSTI)

Modern Methods for Lipid Analysis Chapter 4 Liquid Chromatography/Electrospray Ionization Mass Spectrometry for Analysis of Oxidized Lipids Methods and Analyses eChapters Methods - Analyses Books AOCS Press Downloadable pd

105

Modern Methods for Lipid AnalysisChapter 13 Dual Parallel Liquid Chromatography/Mass Spectrometry for Lipid Analysis  

Science Conference Proceedings (OSTI)

Modern Methods for Lipid Analysis Chapter 13 Dual Parallel Liquid Chromatography/Mass Spectrometry for Lipid Analysis Methods and Analyses eChapters Methods - Analyses Books AOCS Press Downloadable pdf of Chapter

106

Advances in Conjugated Linoleic Acid Research, Vol 2Chapter 2 Gas Chromatography - Mass Spectrometry of Conjugated Linoleic Acids and Metabolites  

Science Conference Proceedings (OSTI)

Advances in Conjugated Linoleic Acid Research, Vol 2 Chapter 2 Gas Chromatography - Mass Spectrometry of Conjugated Linoleic Acids and Metabolites Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistry Dow

107

Extreme Chromatography: Faster, Hotter, SmallerChapter 8 Multiple Parallel Mass Spectrometry Techniques for Lipid and Vitamin D Analysis  

Science Conference Proceedings (OSTI)

Extreme Chromatography: Faster, Hotter, Smaller Chapter 8 Multiple Parallel Mass Spectrometry Techniques for Lipid and Vitamin D Analysis Methods and Analyses eChapters Methods - Analyses Books AOCS Press Downloadable pdf...

108

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

109

Time-resolved studies of particle effects in laser ablation inductively coupled plasma-mass spectrometry  

Science Conference Proceedings (OSTI)

Time resolved signals in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) are studied to determine the influence of experimental parameters on ICP-induced fractionation effects. Differences in sample composition and morphology, i.e., ablating brass, glass, or dust pellets, have a profound effect on the time resolved signal. Helium transport gas significantly decreases large positive signal spikes arising from large particles in the ICP. A binder for pellets also reduces the abundance and amplitude of spikes in the signal. MO{sup +} ions also yield signal spikes, but these MO{sup +} spikes generally occur at different times from their atomic ion counterparts.

Perdian, D.; Bajic, S.; Baldwin, D.; Houk, R.

2007-11-13T23:59:59.000Z

110

The Ramsey method in high-precision mass spectrometry with Penning traps: Experimental results  

E-Print Network (OSTI)

The highest precision in direct mass measurements is obtained with Penning trap mass spectrometry. Most experiments use the interconversion of the magnetron and cyclotron motional modes of the stored ion due to excitation by external radiofrequency-quadrupole fields. In this work a new excitation scheme, Ramsey's method of time-separated oscillatory fields, has been successfully tested. It has been shown to reduce significantly the uncertainty in the determination of the cyclotron frequency and thus of the ion mass of interest. The theoretical description of the ion motion excited with Ramsey's method in a Penning trap and subsequently the calculation of the resonance line shapes for different excitation times, pulse structures, and detunings of the quadrupole field has been carried out in a quantum mechanical framework and is discussed in detail in the preceding article in this journal by M. Kretzschmar. Here, the new excitation technique has been applied with the ISOLTRAP mass spectrometer at ISOLDE/CERN for mass measurements on stable as well as short-lived nuclides. The experimental resonances are in agreement with the theoretical predictions and a precision gain close to a factor of four was achieved compared to the use of the conventional excitation technique.

S. George; K. Blaum; F. Herfurth; A. Herlert; M. Kretzschmar; S. Nagy; S. Schwarz; L. Schweikhard; C. Yazidjian

2007-01-22T23:59:59.000Z

111

Oxalate Mass Balance During Chemical Cleaning in Tank 5F  

SciTech Connect

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

112

OXALATE MASS BALANCE DURING CHEMICAL CLEANING IN TANK 6F  

Science Conference Proceedings (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

113

A study of the formation of cluster ions from metal acetates using plasma desorption mass spectrometry  

E-Print Network (OSTI)

A novel application of desorption/ionization methods of mass spectrometry, e. g. plasma desorption mass spectrometry (PDMS), is the analysis of both the composition and structure of solid materials in one experiment. Cluster ions emitted from the impact of a 252Cf fission fragment on a surface may represent a "view" of the solid construction over atomic distances if composed of atoms from adjacent sites in the surface. A clearer understanding of the mechanism of secondary cluster ion formation is necessary to evaluate the usefulness of PDMS as a surface characterization technique. The aim of this research was to use metal acetate samples to study secondary cluster ion formation in PDMS. In two sets of experiments, metal acetates from period IV and group IIB of the periodic table were used to measure the influence on cluster formation by the ground state electronic configuration and the ionic size, respectively, of the metal constituent. Relative yields for homologous negative and positive secondary cluster ions were determined and compared to thermochemical properties of the metal ion or the metal acetate molecule (AHf and lattice energy). Secondary ions in negative PDMS mass spectra attributable to a gas phase recombination formation mechanism follow trends predicted by these thermochemical properties. Another series of cluster ions, however, with the composition [M(Ac)2]Ac-(where Ac = acetate) does not follow the same trends, indicating possible formation via intact emission from the solid surface. Positive secondary cluster ions showed differences from the negative ions both in the relative yield distribution and the types of ions observed. Positive cluster ions from metal acetates from the fourth period of the periodic table were mainly metal oxides. On the other hand, positive clusters ions from the group IIB of the periodic table were mainly mirror images of the negative spectra. These differences suggest that the bonding characteristics of the metal ion play an important role in the secondary cluster ion formation process.

Mendez Silvagnoli, Winston Reinaldo

1995-01-01T23:59:59.000Z

114

Analysis of fission gas release kinetics by on-line mass spectrometry  

SciTech Connect

The release of fission gas (Xe and Kr) and helium out of nuclear fuel materials in normal operation of a nuclear power reactor can constitute a strong limitation of the fuel lifetime. Moreover, radioactive isotopes of Xe and Kr contribute significantly to the global radiological source term released in the primary coolant circuit in case of accidental situations accompanied by fuel rod loss of integrity. As a consequence, fission gas release investigation is of prime importance for the nuclear fuel cycle economy, and is the driven force of numerous R and D programs. In this domain, for solving current fuel behavior understanding issues, preparing the development of new fuels (e.g. for Gen IV power systems) and for improving the modeling prediction capability, there is a marked need for innovations in the instrumentation field, mainly for: . Quantification of very low fission gas concentrations, released from fuel sample and routed in sweeping lines. Monitoring of quick gas release variations by quantification of elementary release during a short period of time. Detection of a large range of atomic masses (e.g. H{sub 2}, HT, He, CO, CO{sub 2}, Ne, Ar, Kr, Xe), together with a performing separation of isotopes for Xe and Kr elements. Coupling measurement of stable and radioactive gas isotopes, by using in parallel mass spectrometry and gamma spectrometry techniques. To fulfill these challenging needs, a common strategy for analysis equipment implementation has been set up thanks to a recently launched collaboration between the CEA and the Univ. of Provence, with the technological support of the Liverpool Univ.. It aims at developing a chronological series of mass spectrometer devices based upon mass filter and 2D/3D ion traps with Fourier transform operating mode and having increasing levels of performances to match the previous challenges for out-of pile and in-pile experiments. The final objective is to install a high performance online mass spectrometer coupled to a gamma spectrometer in the fission product laboratory of the future Jules Horowitz Material Test Reactor. An intermediate step will consist of testing first equipment on an existing experimental facility in the LECA-STAR Hot Cell Laboratory of the CEA Cadarache. This paper presents the scientific and operational stakes linked to fission gas issues, resumes the current state of art for analyzing them in nuclear facilities, then presents the skills gathered through this collaboration to overcome technological bottlenecks. Finally it describes the implementation strategy in nuclear research facilities of the CEA Cadarache. (authors)

Zerega, Y.; Reynard-Carette, C. [Univ. of Provence, Laboratoire Chimie Provence, UMR 6264, Avenue escadrille Normandie - Niemen, F-13397 Marseille (France); Parrat, D. [CEA, Nuclear Energy Div. DEN, CEA Cadarache, F-13108 Saint-Paul-lez-Durance (France); Carette, M. [Univ. of Provence, Laboratoire Chimie Provence, UMR 6264, Avenue escadrille Normandie - Niemen, F-13397 Marseille (France); Brkic, B. [Univ. of Liverpool, Dept. of Electrical Engineering and Electronics, Liverpool L69 3BX (United Kingdom); Lyoussi, A.; Bignan, G. [CEA, Nuclear Energy Div. DEN, CEA Cadarache, F-13108 Saint-Paul-lez-Durance (France); Janulyte, A.; Andre, J. [Univ. of Provence, Laboratoire Chimie Provence, UMR 6264, Avenue escadrille Normandie - Niemen, F-13397 Marseille (France); Pontillon, Y.; Ducros, G. [CEA, Nuclear Energy Div. DEN, CEA Cadarache, F-13108 Saint-Paul-lez-Durance (France); Taylor, S. [Univ. of Liverpool, Dept. of Electrical Engineering and Electronics, Liverpool L69 3BX (United Kingdom)

2011-07-01T23:59:59.000Z

115

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

SciTech Connect

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

116

Final Report - Advanced Ion Trap Mass Spectrometry Program - Oak Ridge National Laboratory - Sandia National Laboratory  

Science Conference Proceedings (OSTI)

This report covers the three main projects that collectively comprised the Advanced Ion Trap Mass Spectrometry Program. Chapter 1 describes the direct interrogation of individual particles by laser desorption within the ion trap mass spectrometer analyzer. The goals were (1) to develop an ''intelligent trigger'' capable of distinguishing particles of biological origin from those of nonbiological origin in the background and interferent particles and (2) to explore the capability for individual particle identification. Direct interrogation of particles by laser ablation and ion trap mass spectrometry was shown to have good promise for discriminating between particles of biological origin and those of nonbiological origin, although detailed protocols and operating conditions were not worked out. A library of more than 20,000 spectra of various types of biological particles has been assembled. Methods based on multivariate analysis and on neural networks were used to discriminate between particles of biological origin and those of nonbiological origin. It was possible to discriminate between at least some species of bacteria if mass spectra of several hundred similar particles were obtained. Chapter 2 addresses the development of a new ion trap mass analyzer geometry that offers the potential for a significant increase in ion storage capacity for a given set of analyzer operating conditions. This geometry may lead to the development of smaller, lower-power field-portable ion trap mass spectrometers while retaining laboratory-scale analytical performance. A novel ion trap mass spectrometer based on toroidal ion storage geometry has been developed. The analyzer geometry is based on the edge rotation of a quadrupolar ion trap cross section into the shape of a torus. Initial performance of this device was poor, however, due to the significant contribution of nonlinear fields introduced by the rotation of the symmetric ion-trapping geometry. These nonlinear resonances contributed to poor mass resolution and sensitivity and to erratic ion ejection behavior. To correct for these nonlinear effects, the geometry of the toroid ion trap analyzer has been modified to create an asymmetric torus, as first suggested by computer simulations that predicted significantly improved performance and unit mass resolution for this geometry. A reduced-sized version (one-fifth scale) has been fabricated but was not tested within the scope of this project. Chapter 3 describes groundbreaking progress toward the use of ion-ion chemistry to control the charge state of ions formed by the electrospray ionization process, which in turn enables precision analysis of whole proteins. In addition, this technique may offer the unique possibility of a priori identification of unknown biological material when employed with existing proteomics and genomic databases. Ion-ion chemistry within the ion trap was used to reduce the ions in highly charged states to states of +1 and +2 charges. Reduction in charge greatly simplifies identification of molecular weights of fragments from large biological molecules. This technique enables the analysis of whole proteins as biomarkers for the detection and identification of all three classes of biological weapons (bacteria, toxins, and viruses). In addition to methods development, tests were carried out with samples of tap water, local creek water, and soil (local red clay) spiked with melittin (bee venom), cholera toxin, and virus MS2. All three analytes were identified in tap water and soil; however, all three were problematic for detection in creek water at concentrations of 1 nM. More development of methods is needed.

Whitten, W.B.

2002-12-18T23:59:59.000Z

117

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

Science Conference Proceedings (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

118

Nuclear Materials Identification System (NMIS) with Gamma Spectrometry for Attributes of Pu, HEU, and Detection of HE and Chemical Agents  

SciTech Connect

A combined Nuclear Materials Identification System (NMIS)-gamma ray spectrometry system can be used passively to obtain the following attributes of Pu: presence, fissile mass, 240/239 ratio, and metal vs. oxide. This system can also be used with a small, portable, DT neutron generator to measure the attributes of highly enriched uranium (HEU): presence, fissile mass, enrichment, metal vs. oxide; and detect the presence of high explosives (HE). For the passive system, time-dependent coincidence distributions can be used for the presence, fissile mass, metal vs. oxide for Pu, and gamma-ray spectrometry can be used for 239/240 ratio and presence. So presence can be confirmed by two methods. For the active system with a DT neutron generator, all four attributes for both Pu and HEU can be determined from various features of the time-dependent coincidence distribution measurements for both Pu and HEU. Active gamma ray spectrometry would also give presence and 240/239 ratio for Pu, enrichment for HEU, and metal vs. oxide for both. Active gamma ray spectrometry would determine the presence of HE. The various features of time-dependent coincidence distributions and gamma ray spectrometry that determine these attributes are discussed with some examples from previous determinations.

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

2002-05-01T23:59:59.000Z

119

ESI/Ion Trap/Ion Mobility/Time-of-Flight Mass Spectrometry for Rapid and Sensitive Analysis of  

E-Print Network (OSTI)

discuss a new separation strategy for biomolecules that is based on differences in ion mobilitiesESI/Ion Trap/Ion Mobility/Time-of-Flight Mass Spectrometry for Rapid and Sensitive Analysis* Department of Chemistry, Indiana University, Bloomington, Indiana 47405 An ion trap/ion mobility

Clemmer, David E.

120

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

Science Conference Proceedings (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

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121

An Automated Platform for High-Resolution Tissue Imaging Using Nanospray Desorption Electrospray Ionization Mass Spectrometry  

SciTech Connect

An automated platform has been developed for acquisition and visualization of mass spectrometry imaging (MSI) data using nanospray desorption electrospray ionization (nano-DESI). The new system enables robust operation of the nano-DESI imaging source over many hours. This is achieved by controlling the distance between the sample and the probe by mounting the sample holder onto an automated XYZ stage and defining the tilt of the sample plane. This approach is useful for imaging of relatively flat samples such as thin tissue sections. Custom software called MSI QuickView was developed for visualization of large data sets generated in imaging experiments. MSI QuickView enables fast visualization of the imaging data during data acquisition and detailed processing after the entire image is acquired. The performance of the system is demonstrated by imaging rat brain tissue sections. High resolution mass analysis combined with MS/MS experiments enabled identification of lipids and metabolites in the tissue section. In addition, high dynamic range and sensitivity of the technique allowed us to generate ion images of low-abundance isobaric lipids. High-spatial resolution image acquired over a small region of the tissue section revealed the spatial distribution of an abundant brain metabolite, creatine, in the white and gray matter that is consistent with the literature data obtained using magnetic resonance spectroscopy.

Lanekoff, Ingela T.; Heath, Brandi S.; Liyu, Andrey V.; Thomas, Mathew; Carson, James P.; Laskin, Julia

2012-10-02T23:59:59.000Z

122

Studies of selenium and xenon in inductively coupled plasma mass spectrometry  

SciTech Connect

Since its development, inductively coupled plasma mass spectrometry (ICP-MS) has been a widely used analytical technique. ICP-MS offers low detection limits, easy determination of isotope ratios, and simple mass spectra from analyte elements. ICP-MS has been successfully employed for many applications including geological, environmental, biological, metallurgical, food, medical, and industrial. One specific application important to many areas of study involves elemental speciation by using ICP-MS as an element specific detector interfaced to liquid chromatography. Elemental speciation information is important and cannot be obtained by atomic spectrometric methods alone which measure only the total concentration of the element present. Part 1 of this study describes the speciation of selenium in human serum by size exclusion chromatography (SEC) and detection by ICP-MS. Although ICP-MS has been widely sued, room for improvement still exists. Difficulties in ICP-MS include noise in the background, matrix effects, clogging of the sampling orifice with deposited solids, and spectral interference caused by polyatomic ions. Previous work has shown that the addition of xenon into the central channel of the ICP decreases polyatomic ion levels. In Part 2 of this work, a fundamental study involving the measurement of the excitation temperature is carried out to further understand xenon`s role in the reduction of polyatomic ions. 155 refs.

Bricker, T.

1994-07-27T23:59:59.000Z

123

MASS SPECTROMETRIC APPROACHES FOR CHEMICAL CHARACTERISATION OF ATMOSPHERIC AEROSOLS: CRITICAL REVIEW OF MOST RECENT ADVANCES  

Science Conference Proceedings (OSTI)

This manuscript presents an overview of the most recent instrument developments, field and laboratory applications of mass spectrometry (MS) in chemistry and physics of atmospheric aerosols. A broad range of MS instruments employing different sample introduction methods, ionization and mass detection techniques are utilized for both 'on-line' and 'off-line' characterization of aerosols. On-line MS techniques enable detection of individual particles with simultaneous measurements of particle size distributions and aerodynamic characteristics, and are ideally suited for field studies which require high temporal resolution. Off-line MS techniques provide means for detailed molecular-level analysis of aerosol samples which is essential to fundamental knowledge on aerosol chemistry, mechanisms of particle formation and atmospheric aging. Combined together, complementary MS techniques provide comprehensive information on the chemical composition, size, morphology and phase of aerosols - data of key importance for evaluating hygroscopic and optical properties of particles, their health effects, understanding their origins, and atmospheric evolution. Developments and applications of MS techniques in the aerosol research have expanded remarkably over a couple of last years as evidenced by sky-rocketing publication statistics. The goal of this review is to period of late 2010 - early 2012, which were not conveyed in previous reviews.

Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

2012-06-29T23:59:59.000Z

124

Facilities: NHMFL 14.5 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer Citation: A Pseudoatomic Model of the COPII Cage Obtained from Cryo-Electron Microscopy and Mass Spectrometry,  

E-Print Network (OSTI)

Facilities: NHMFL 14.5 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer Citation ultrahigh-resolution 14.5 tesla Fourier transform ion cyclotron resonance mass spectrometry. The Mag

Weston, Ken

125

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

Science Conference Proceedings (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

126

Accelerator Mass Spectrometry Measurements of Plutonium in Sediment and Seawater from the Marshall Islands  

Science Conference Proceedings (OSTI)

During the summer 2000, I was given the opportunity to work for about three months as a technical trainee at Lawrence Livermore National Laboratory, or LLNL as I will refer to it hereafter. University of California runs this Department of Energy laboratory, which is located 70 km east of San Francisco, in the small city of Livermore. This master thesis in Radioecology is based on the work I did here. LLNL, as a second U.S.-facility for development of nuclear weapons, was built in Livermore in the beginning of the 1950's (Los Alamos in New Mexico was the other one). It has since then also become a 'science center' for a number of areas like magnetic and laser fusion energy, non-nuclear energy, biomedicine, and environmental science. The Laboratory's mission has changed over the years to meet new national needs. The following two statements were found on the homepage of LLNL (http://www.llnl.gov), at 2001-03-05, where also information about the laboratory and the scientific projects that takes place there, can be found. 'Our primary mission is to ensure that the nation's nuclear weapons remain safe, secure, and reliable and to prevent the spread and use of nuclear weapons worldwide'. 'Our goal is to apply the best science and technology to enhance the security and well-being of the nation and to make the world a safer place.' The Marshall Islands Dose Assessment and Radioecology group at the Health and Ecological Assessments division employed me, and I also worked to some extent with the Centre for Accelerator Mass Spectrometry (CAMS) group. The work I did at LLNL can be divided into two parts. In the first part Plutonium (Pu) measurements in sediments from the Rongelap atoll in Marshall Islands, using Accelerator Mass Spectrometry (AMS) were done. The method for measuring these kinds of samples is well understood at LLNL since soil samples have been measured with AMS for Pu in the past. Therefore it was the results that were of main interest and not the technique. The second part was to take advantage of AMS's very high sensitivity by measure the Pu-concentrations in small volumes (0.04-1 L) of seawater. The technique for using AMS at Pu-measurements in seawater is relatively new and the main task for me was to find out a method that could work in practice. The area where the sediment samples and the water samples were collected are high above background levels for many radionuclides, including Pu, because of the detonation of the nuclear bomb code-named Castle Bravo, in 1954.

Leisvik, M; Hamilton, T

2001-08-01T23:59:59.000Z

127

Imaging Nicotine in Rat Brain Tissue by Use of Nanospray Desorption Electrospray Ionization Mass Spectrometry  

SciTech Connect

Imaging mass spectrometry offers simultaneous detection of drugs, drug metabolites and endogenous substances in a single experiment. This is important when evaluating effects of a drug on a complex organ system such as the brain, where there is a need to understand how regional drug distribution impacts function. Nicotine is an addictive drug and its action in the brain is of high interest. Here we use nanospray desorption electrospray ionization, nano-DESI, imaging to discover the localization of nicotine in rat brain tissue after in vivo administration of nicotine. Nano-DESI is a new ambient technique that enables spatially-resolved analysis of tissue samples without special sample pretreatment. We demonstrate high sensitivity of nano-DESI imaging that enables detection of only 0.7 fmole nicotine per pixel in the complex brain matrix. Furthermore, by adding deuterated nicotine to the solvent, we examined how matrix effects, ion suppression, and normalization affect the observed nicotine distribution. Finally, we provide preliminary results suggesting that nicotine localizes to the hippocampal substructure called dentate gyrus.

Lanekoff, Ingela T.; Thomas, Mathew; Carson, James P.; Smith, Jordan N.; Timchalk, Charles; Laskin, Julia

2013-01-15T23:59:59.000Z

128

Determination of the stellar (n,gamma) cross section of 40Ca with accelerator mass spectrometry  

E-Print Network (OSTI)

The stellar (n,gamma) cross section of 40Ca at kT=25 keV has been measured with a combination of the activation technique and accelerator mass spectrometry (AMS). This combination is required when direct off-line counting of the produced activity is compromised by the long half-life and/or missing gamma-ray transitions. The neutron activations were performed at the Karlsruhe Van de Graaff accelerator using the quasistellar neutron spectrum of kT=25 keV produced by the 7Li(p,n)7Be reaction. The subsequent AMS measurements were carried out at the Vienna Environmental Research Accelerator (VERA) with a 3 MV tandem accelerator. The doubly magic 40Ca is a bottle-neck isotope in incomplete silicon burning, and its neutron capture cross section determines the amount of leakage, thus impacting on the eventual production of iron group elements. Because of its high abundance, 40Ca can also play a secondary role as "neutron poison" for the s-process. Previous determinations of this value at stellar energies were based on time-of-flight measurements. Our method uses an independent approach, and yields for the Maxwellian-averaged cross section at kT=30 keV a value of 30 keV= 5.73+/-0.34 mb.

I. Dillmann; C. Domingo-Pardo; M. Heil; F. Käppeler; A. Wallner; O. Forstner; R. Golser; W. Kutschera; A. Priller; P. Steier; A. Mengoni; R. Gallino; M. Paul; C. Vockenhuber

2009-07-01T23:59:59.000Z

129

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 an electron ionization source, a quadrupole mass spectrometer, a uniform field drift cell spectrometer encased in a cryogenic envelope, and an orthogonal geometry time-of-flight mass spectrometer. The analytical benefits of low temperature ion mobility are discussed in terms of enhanced separation ability, ion selectivity and sensitivity. The distinction between resolving power and resolution for ion mobility is also discussed. Detailed experimental designs and rationales are provided for each instrument component. Tuning and calibration data and methods are also provided for the technique. Proof-of-concept experiments for an array of analytes including rare gases (argon, krypton, xenon), hydrocarbons (acetone, ethylene glycol, methanol), and halides (carbon tetrachloride) are provided in order to demonstrate the advantages and limitations of the instrument for obtaining analytically useful information. Trendline partitioning of small analyte ions based on chemical composition is demonstrated as a novel chemical analysis method. The utility of mobility-mass analysis for mass selected ions is also demonstrated, particularly for probing the ion chemistry which occurs in the drift tube for small mass ions. As a final demonstration of the separation abilities of the instrument, the electronic states of chromium and titanium (ground and excited) are separated with low temperature. The transition metal electronic state separations demonstrated here are at the highest resolution ever obtained for ion mobility methods. The electronic conformational mass isomers of methanol (conventional and distonic) are also partially separated at low temperature. Various drift gases (helium, neon, and argon) are explored for the methanol system in order to probe stronger ion-neutral interaction potentials and effectuate higher resolution separations of the two isomeric ions. Finally, two versatile ion source designs and a method for axially focusing ions at low pressure (1-10 torr) using electrostatic fields is presented along with some preliminary work on the ion sources.

May, Jody C.

2009-08-01T23:59:59.000Z

130

Modern Methods for Lipid AnalysisChapter 12 Toward Total Cellular Lipidome Analysis by ESI Mass Spectrometry from a Crude Lipid Extract  

Science Conference Proceedings (OSTI)

Modern Methods for Lipid Analysis Chapter 12 Toward Total Cellular Lipidome Analysis by ESI Mass Spectrometry from a Crude Lipid Extract Methods and Analyses eChapters Methods - Analyses Books AOCS Press Downloadable pdf ...

131

Lipid Analysis and Lipidomics: New Techniques & ApplicationChapter 3 Global Cellular Lipidome Analyses by Shotgun Lipidomics Using Multidimensional Mass Spectrometry  

Science Conference Proceedings (OSTI)

Lipid Analysis and Lipidomics: New Techniques & Application Chapter 3 Global Cellular Lipidome Analyses by Shotgun Lipidomics Using Multidimensional Mass Spectrometry Methods and Analyses eChapters Methods - Analyses Books 2D17DD82D1DB9F2

132

Modern Methods for Lipid AnalysisChapter 2 Analysis of Phospholipids by Liquid Chromatography Coupled with Online Electrospray Ionization Mass Spectrometry  

Science Conference Proceedings (OSTI)

Modern Methods for Lipid Analysis Chapter 2 Analysis of Phospholipids by Liquid Chromatography Coupled with Online Electrospray Ionization Mass Spectrometry Methods and Analyses eChapters Methods - Analyses Books AOCS Press A76556A5B4

133

Lipid Analysis and Lipidomics: New Techniques & ApplicationChapter 2 An Overview of Modern Mass Spectrometry Methods in the Toolbox of Lipid Chemists and Biochemists  

Science Conference Proceedings (OSTI)

Lipid Analysis and Lipidomics: New Techniques & Application Chapter 2 An Overview of Modern Mass Spectrometry Methods in the Toolbox of Lipid Chemists and Biochemists Methods and Analyses eChapters Methods - Analyses Books Dow

134

Nutrition and Biochemistry of PhospholipidsChapter 9 Compositional Analysis of Complex Mixtures of Sphingolipids by Liquid Chromatography — Tandem Mass Spectrometry  

Science Conference Proceedings (OSTI)

Nutrition and Biochemistry of Phospholipids Chapter 9 Compositional Analysis of Complex Mixtures of Sphingolipids by Liquid Chromatography — Tandem Mass Spectrometry Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemist

135

Extreme Chromatography: Faster, Hotter, SmallerChapter 6 Silver-ion High-performance Liquid Chromatography—Mass Spectrometry in the Analysis of Lipids  

Science Conference Proceedings (OSTI)

Extreme Chromatography: Faster, Hotter, Smaller Chapter 6 Silver-ion High-performance Liquid Chromatography—Mass Spectrometry in the Analysis of Lipids Methods and Analyses eChapters Methods - Analyses Books Downloadable pdf...

136

Modern Methods for Lipid AnalysisChapter 7 Qualitative and Quantitative Analysis of Triacylglycerolsby Atmospheric Pressure Ionization (APCI and ESI) Mass Spectrometry Techniques  

Science Conference Proceedings (OSTI)

Modern Methods for Lipid Analysis Chapter 7 Qualitative and Quantitative Analysis of Triacylglycerolsby Atmospheric Pressure Ionization (APCI and ESI) Mass Spectrometry Techniques Methods and Analyses eChapters Methods - Analyses Books AO

137

Modern Methods for Lipid AnalysisChapter 3 Electrospray Ionization with Low-Energy Collisionally Activated Dissociation Tandem Mass Spectrometry of Complex Lipids:  

Science Conference Proceedings (OSTI)

Modern Methods for Lipid Analysis Chapter 3 Electrospray Ionization with Low-Energy Collisionally Activated Dissociation Tandem Mass Spectrometry of Complex Lipids: Methods and Analyses eChapters Methods - Analyses Books AOCS Press ...

138

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

Science Conference Proceedings (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

139

Mass Transfer Constraints On The Chemical Evolution Of An Active...  

Open Energy Info (EERE)

rock and fluids, and mass balances calculations involving Cl in the glass phase, produced comparable water-rock ratios of unity, confirming the importance of irreversible...

140

Studies of Atmospheric Chemistry and Reaction Mechanisms Using Optical Spectroscopy and Mass Spectrometry  

E-Print Network (OSTI)

measurement system of peroxy radicals using a chemical amplification/laser-measurement system of peroxy radicals using a chemical amplification/laser-

Liu, Yingdi

2011-01-01T23:59:59.000Z

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
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141

Single Particle Laser Mass Spectrometry Applied to Differential Ice Nucleation Experiments at the AIDA Chamber  

SciTech Connect

Experiments conducted at the Aerosol Interactions and Dynamics in the Atmosphere (AIDA) chamber located in Karlsruhe, Germany permit investigation of particle properties that affect the nucleation of ice at temperature and water vapor conditions relevant to cloud microphysics and climate issues. Ice clouds were generated by heterogeneous nucleation of Arizona test dust (ATD), illite, and hematite and homogeneous nucleation of sulfuric acid. Ice crystals formed in the chamber were inertially separated from unactivated, or ‘interstitial’ aerosol particles with a pumped counterflow virtual impactor (PCVI), then evaporated. The ice residue (i.e., the aerosol which initiated ice nucleation plus any material which was scavenged from the gas- and/or particle-phase), was chemically characterized at the single particle level using a laser ionization mass spectrometer. In this manner the species that first nucleated ice could be identified out of a mixed aerosol population in the chamber. Bare mineral dust particles were more effective ice nuclei (IN) than similar particles with a coating. Metallic particles from contamination in the chamber initiated ice nucleation before other species but there were few enough that they did not compromise the experiments. Nitrate, sulfate, and organics were often detected on particles and ice residue, evidently from scavenging of trace gas-phase species in the chamber. Hematite was a more effective ice nucleus than illite. Ice residue was frequently larger than unactivated test aerosol due to the formation of aggregates due to scavenging, condensation of contaminant gases, and the predominance of larger aerosol in nucleation.

Gallavardin, S. J.; Froyd, Karl D.; Lohmann, U.; Moehler, Ottmar; Murphy, Daniel M.; Cziczo, Dan

2008-08-26T23:59:59.000Z

142

A Chemical Ionization Mass Spectrometer for Ground-Based Measurements of Nitric Acid  

Science Conference Proceedings (OSTI)

A chemical ionization mass spectrometer (CIMS) instrument has been developed for high-precision measurements of gaseous nitric acid (HNO3) specifically under high- and variable-humidity conditions in the boundary layer. The instrument’s ...

Kazuyuki Kita; Yu Morino; Yutaka Kondo; Yuichi Komazaki; Nobuyuki Takegawa; Yuzo Miyazaki; Jun Hirokawa; Shigeru Tanaka; Thomas L. Thompson; Ru-Shan Gao; David W. Fahey

2006-08-01T23:59:59.000Z

143

Gas-phase and Solution-phase Peptide Conformations Studied by Ion Mobility-mass Spectrometry and Molecular Dynamics Simulations  

E-Print Network (OSTI)

Ion mobility spectrometry (IMS) separates ions on the basis of ion-neutral collision cross-sections (CCS, [omega]), which are determined by the geometry or conformation of the ions. The size-based IM separation can be extended to distinguish conformers that have different shapes in cases where shape differences influence the accessible surface area of the molecule. In recent years, IM has rapidly evolved as a structural characterization technique, which has applied on various structural biology problems. In this work, IMS is combined with molecular dynamics simulation (MDS), specially the integrated tempering sampling molecular dynamics simulation (ITS-MDS) to explore the gas-phase conformation space of two molecular systems (i) protonated tryptophan zipper 1 (trpzip1) ions and its six derivatives (ii) alkali metal ion (Na, K and Cs) adducts of gramicidin A (GA). The structural distributions obtained from ITS-MDS are compared well with results obtained from matrix-assisted laser desorption ionization-ion mobility-mass spectrometry (MALDI-IM-MS) for trpzip 1 series and electrospray ionization-ion mobility-mass spectrometry (ESI-IM-MS) for alkali metal ion adducts of GA. Furthermore, the solvent dependence on conformational preferences of the GA dimer is investigated using a combination of mass spectrometry techniques, viz. ESI-IM-MS and hydrogen/deuterium exchange (HDX)-MS, and MDS. The IM experiments reveal three distinct gramicidin A species, detected as the sodium ion adduct ions, [2GA + 2Na]˛?, and the equilibrium abundances of the dimer ions varies with solvent polarity. The solution phase conformations are assigned as the parallel and anti-parallel [beta]-helix dimer, and the anti-parallel dimer is the preferred conformation in non-polar organic solvent. The calculated CCS profiles by ITS-MDS agree very well with the experimentally measured CCS profiles, which underscore the utility of the method for determining candidate structures as well as the relative abundances of the candidate structures. The benefit of combining ion mobility measurements with solution-phase H/D exchange is allowing identifications and detail analysis of the solution-phase subgroup conformations, which cannot be uncovered by one method alone.

Chen, Liuxi

2012-08-01T23:59:59.000Z

144

Formic acid oxidation in a polymer electrolyte fuel cell: A real-time mass-spectrometry study  

Science Conference Proceedings (OSTI)

The electro-oxidation of formic acid was studied in a direct-oxidation polymer-electrolyte fuel cell at 170 C using real-time mass spectrometry. The results are compared with those obtained for methanol oxidation under the same conditions. Formic acid was electrochemically more active than methanol on both Pt-black and Pt-Ru catalysts. The polarization potential of formic acid oxidation was ca. 90 to 100 mV lower than that of methanol. The oxidation of formic acid was dependent on the water/formic acid mole ratio. The best anode performance was obtained using a water/formic acid mole ratio of {approximately}2. In addition, Pt/Ru catalyst was more active than Pt-black for formic acid oxidation. The mass spectrometric results showed that CO{sub 2} is the only reaction product of formic acid oxidation. The results are discussed in terms of possible formic acid oxidation mechanisms.

Weber, M.; Wang, J.T.; Wasmus, S.; Savinell, R.F. [Case Western Reserve Univ., Cleveland, OH (United States)

1996-07-01T23:59:59.000Z

145

Quark-mass dependence of three-flavor QCD at zero and imaginary chemical potential  

E-Print Network (OSTI)

We draw the three-flavor phase diagram as a function of light and strange quark masses for both zero and imaginary quark-number chemical potential, using the Polyakov-loop extended Nambu--Jona-Lasinio model with an effective four-quark vertex depending on the Polyakov loop. The model prediction is consistent with 2+1 flavor lattice QCD prediction at zero chemical potential and with degenerate three-flavor lattice QCD prediction at imaginary chemical potential.

Sasaki, Takahiro; Kouno, Hiroaki; Yahiro, Masanobu

2011-01-01T23:59:59.000Z

146

Laser desorption/ionization mass spectrometry for direct profiling and imaging of small molecules from raw biological materials  

DOE Green Energy (OSTI)

Matrix-assisted laser desorption/ionization(MALDI) mass spectrometry(MS) has been widely used for analysis of biological molecules, especially macromolecules such as proteins. However, MALDI MS has a problem in small molecule (less than 1 kDa) analysis because of the signal saturation by organic matrixes in the low mass region. In imaging MS (IMS), inhomogeneous surface formation due to the co-crystallization process by organic MALDI matrixes limits the spatial resolution of the mass spectral image. Therefore, to make laser desorption/ionization (LDI) MS more suitable for mass spectral profiling and imaging of small molecules directly from raw biological tissues, LDI MS protocols with various alternative assisting materials were developed and applied to many biological systems of interest. Colloidal graphite was used as a matrix for IMS of small molecules for the first time and methodologies for analyses of small metabolites in rat brain tissues, fruits, and plant tissues were developed. With rat brain tissues, the signal enhancement for cerebroside species by colloidal graphite was observed and images of cerebrosides were successfully generated by IMS. In addition, separation of isobaric lipid ions was performed by imaging tandem MS. Directly from Arabidopsis flowers, flavonoids were successfully profiled and heterogeneous distribution of flavonoids in petals was observed for the first time by graphite-assisted LDI(GALDI) IMS.

Cha, Sangwon

2008-05-15T23:59:59.000Z

147

Deconstruction of Activity-Dependent Covalent Modification of Heme in Human Neutrophil Myeloperoxidase by Multistage Mass Spectrometry (MS[superscript 4])  

SciTech Connect

Myeloperoxidase (MPO) is known to be inactivated and covalently modified by treatment with hydrogen peroxide and agents similar to 3-(2-ethoxypropyl)-2-thioxo-2,3-dihydro-1H-purin-6(9H)-one (1), a 254.08 Da derivative of 2-thioxanthine. Peptide mapping by liquid chromatography and mass spectrometry detected modification by 1 in a labile peptide-heme-peptide fragment of the enzyme, accompanied by a mass increase of 252.08 Da. The loss of two hydrogen atoms was consistent with mechanism-based oxidative coupling. Multistage mass spectrometry (MS{sup 4}) of the modified fragment in an ion trap/Orbitrap spectrometer demonstrated that 1 was coupled directly to heme. Use of a 10 amu window delivered the full isotopic envelope of each precursor ion to collision-induced dissociation, preserving definitive isotopic profiles for iron-containing fragments through successive steps of multistage mass spectrometry. Iron isotope signatures and accurate mass measurements supported the structural assignments. Crystallographic analysis confirmed linkage between the methyl substituent of the heme pyrrole D ring and the sulfur atom of 1. The final orientation of 1 perpendicular to the plane of the heme ring suggested a mechanism consisting of two consecutive one-electron oxidations of 1 by MPO. Multistage mass spectrometry using stage-specific collision energies permits stepwise deconstruction of modifications of heme enzymes containing covalent links between the heme group and the polypeptide chain.

Geoghegan, Kieran F.; Varghese, Alison H.; Feng, Xidong; Bessire, Andrew J.; Conboy, James J.; Ruggeri, Roger B.; Ahn, Kay; Spath, Samantha N.; Filippov, Sergey V.; Conrad, Steven J.; Carpino, Philip A.; Guimarăes, Cristiano R.W.; Vajdos, Felix F. (Pfizer)

2013-03-07T23:59:59.000Z

148

Science of Signatures Workshop on Secondary Ion Mass Spectrometry (SIMS) Applications July 24, 2012  

SciTech Connect

The science of signatures focus areas are: (1) Radiological and Nuclear; (2) Chemical and Materials (including explosives); (3) Biological - Signatures of Disease and Health; (4) Energy; (5) Climate; and (6) Space.

Hickmott, Donald D [Los Alamos National Laboratory; Riciputi, Lee D [Los Alamos National Laboratory

2012-07-23T23:59:59.000Z

149

Use of Proton-Transfer-Reaction Mass Spectrometry to Characterize Volatile Organic Compound Sources at the La Porte Super Site During the Texas Air Quality Study 2000  

SciTech Connect

Proton-transfer-reaction mass spectrometry (PTR-MS) was deployed for continuous real-time monitoring of volatile organic compounds (VOCs) at a site near the Houston Ship Channel during the Texas Air Quality Study 2000. Overall, 28 ions dominated the PTR-MS mass spectra and were assigned as anthropogenic aromatics (e.g., benzene, toluene, xylenes) and hydrocarbons (propene, isoprene), oxygenated compounds (e.g., formaldehyde, acetaldehyde, acetone, methanol, C7 carbonyls), and three nitrogencontaining compounds (e.g., HCN, acetonitrile and acrylonitrile). Biogenic VOCs were minor components at this site. Propene was the most abundant lightweight hydrocarbon detected by this technique with concentrations up to 100+ nmol mol-1, and was highly correlated with its oxidation products, formaldehyde (up to ~40 nmol mol-1) and acetaldehyde (up to ~80 nmol/mol), with typical ratios close to 1 in propene-dominated plumes. In the case of aromatic species the high time resolution of the obtained data set helped in identifying different anthropogenic sources (e.g., industrial from urban emissions) and testing current emission inventories. A comparison with results from complimentary techniques (gas chromatography, differential optical absorption spectroscopy) was used to assess the selectivity of this on-line technique in a complex urban and industrial VOC matrix and give an interpretation of mass scans obtained by ‘‘soft’’ chemical ionization using proton-transfer via H3O+. The method was especially valuable in monitoring rapidly changing VOC plumes which passed over the site, and when coupled with meteorological data it was possible to identify likely sources.

Karl, Thomas G.; Jobson, B Tom T.; Kuster, W. C.; Williams, Eric; Stutz, Jochen P.; Shetter, Rick; Hall, Samual R.; Goldan, P. D.; Fehsenfeld, Fred C.; Lindinger, Werner

2003-08-19T23:59:59.000Z

150

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.

Litvinov, Y A; Geissel, H; Weick, H; Beckert, Karl; Beller, Peter; Boutin, D; Brandau, C; Chen, L; Klepper, O; Knöbel, R; Kozhuharov, C; Kurcewicz, J; Litvinov, S A; Mazzocco, M; Münzenberg, G; Nociforo, C; Nolden, F; Plass, W; Scheidenberger, C; Steck, Markus; Sun, B; Winkler, M; Litvinov, Yu.A.

2005-01-01T23:59:59.000Z

151

First accelerator mass spectrometry {sup 14}C dates documenting contemporaneity of nonanalog species in late Pleistocene mammal communities  

Science Conference Proceedings (OSTI)

Worldwide late Pleistocene terrestrial mammal faunas are characterized by stratigraphic associations of species that now have exclusive geographic ranges. These have been interpreted as either taphonomically mixed or representative of communities that no longer exist. Accelerator mass spectrometry {sup 14}C dates (n = 60) on single bones of stratigraphically associated fossil micromammals from two American and two Russian sites document for the first time that currently allopatric mammals occurred together between 12,000 and 22,000 yr B.P. on two continents. The existence of mammal communities without modern analogs demonstrates that Northern Hemisphere biological communities are ephemeral and that many modern biomes are younger than 12 ka. Future climate change may result in new nonanalog communities.

Stafford, T.W. Jr.; Semken, H.A. Jr.; Graham, R.W.; Klippel, W.F.; Markova, A.; Smirnov, N.G.; Southon, J.

1999-10-01T23:59:59.000Z

152

Organic aerosol components observed in Northern Hemispheric datasets from Aerosol Mass Spectrometry  

E-Print Network (OSTI)

In this study we compile and present results from the factor analysis of 43 Aerosol Mass Spectrometer (AMS) datasets (27 of the datasets are reanalyzed in this work). The components from all sites, when taken together, ...

Kroll, Jesse

153

Elemental analysis of aerosol organic nitrates with electron ionization high-resolution mass spectrometry  

E-Print Network (OSTI)

Four hydroxynitrates (R(OH)R'ONO2) representative of atmospheric volatile organic compound (VOC) oxidation products were synthesized, nebulized and sampled into an Aerodyne High Resolution Time of Flight Aerosol Mass ...

Rollins, A. W.

154

Literature survey of chemical analysis by thermal neutron induced capture gamma ray spectrometry  

DOE Green Energy (OSTI)

A brief discussion of the principles and techniques of chemical analysis by neutron capture gamma radiation is presented, and the widely scattered literature is collected into a single table arranged by element measured.

Gladney, E.S.

1979-09-01T23:59:59.000Z

155

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

Science Conference Proceedings (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

156

Design and performance of a combined secondary ion mass spectrometry-scanning probe microscopy instrument for high sensitivity and high-resolution elemental three-dimensional analysis  

Science Conference Proceedings (OSTI)

State-of-the-art secondary ion mass spectrometry (SIMS) instruments allow producing 3D chemical mappings with excellent sensitivity and spatial resolution. Several important artifacts however arise from the fact that SIMS 3D mapping does not take into account the surface topography of the sample. In order to correct these artifacts, we have integrated a specially developed scanning probe microscopy (SPM) system into a commercial Cameca NanoSIMS 50 instrument. This new SPM module, which was designed as a DN200CF flange-mounted bolt-on accessory, includes a new high-precision sample stage, a scanner with a range of 100 {mu}m in x and y direction, and a dedicated SPM head which can be operated in the atomic force microscopy (AFM) and Kelvin probe force microscopy modes. Topographical information gained from AFM measurements taken before, during, and after SIMS analysis as well as the SIMS data are automatically compiled into an accurate 3D reconstruction using the software program 'SARINA,' which was developed for this first combined SIMS-SPM instrument. The achievable lateral resolutions are 6 nm in the SPM mode and 45 nm in the SIMS mode. Elemental 3D images obtained with our integrated SIMS-SPM instrument on Al/Cu and polystyrene/poly(methyl methacrylate) samples demonstrate the advantages of the combined SIMS-SPM approach.

Wirtz, Tom; Fleming, Yves; Gerard, Mathieu [Department 'Science and Analysis of Materials' (SAM), Centre de Recherche Public, Gabriel Lippmann, 41 rue du Brill, L-4422 Belvaux (Luxembourg); Gysin, Urs; Glatzel, Thilo; Meyer, Ernst [Department of Physics, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Wegmann, Urs [Department of Physics, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Ferrovac GmbH, Thurgauerstr. 72, CH-8050 Zuerich (Switzerland); Maier, Urs [Ferrovac GmbH, Thurgauerstr. 72, CH-8050 Zuerich (Switzerland); Odriozola, Aitziber Herrero; Uehli, Daniel [SPECS Zurich GmbH, Technoparkstr. 1, CH-8005 Zuerich (Switzerland)

2012-06-15T23:59:59.000Z

157

High-Resolution Electrospray Ionization Mass Spectrometry Analysis of Water- Soluble Organic Aerosols Collected with a Particle into Liquid Sampler  

DOE Green Energy (OSTI)

This work demonstrates the utility of a particle-into-liquid sampler (PILS) a technique traditionally used for identification of inorganic ions present in ambient or laboratory aerosols for the analysis of water soluble organic aerosol (OA) using high resolution electrospray ionization mass spectrometry (HR ESI-MS). Secondary organic aerosol (SOA) was produced from 0.5 ppm mixing ratios of limonene and ozone in a 5 m3 Teflon chamber. SOA was collected simultaneously using a traditional filter sampler and a PILS. The filter samples were later extracted with either water or acetonitrile, while the aqueous PILS samples were analyzed directly. In terms of peak intensities, types of detectable compounds, average O:C ratios, and organic mass to organic carbon ratios, the resulting high resolution mass spectra were essentially identical for the PILS and filter based samples. SOA compounds extracted from both filter/acetonitrile extraction and PILS/water extraction accounted for >95% of the total ion current in ESI mass spectra. This similarity was attributed to high solubility of limonene SOA in water. In contrast, significant differences in detected ions and peak abundances were observed for pine needle biomass burning organic aerosol (BBOA) collected with PILS and filter sampling. The water soluble fraction of BBOA is considerably smaller than for SOA, and a number of unique peaks were detectable only by the filter/acetonitrile method. The combination of PILS collection with HR-ESI-MS analysis offers a new approach for molecular analysis of the water-soluble organic fraction in biogenic SOA, aged photochemical smog, and BBOA.

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

2010-10-01T23:59:59.000Z

158

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

159

Mass spectrometry-based methods for detection and differentiation of botulinum neurotoxins  

DOE Patents (OSTI)

The present invention is directed to a method for detecting the presence of clostridial neurotoxins in a sample by mixing a sample with a peptide that can serve as a substrate for proteolytic activity of a clostridial neurotoxin; and measuring for proteolytic activity of a clostridial neurotoxin by a mass spectroscopy technique. In one embodiment, the peptide can have an affinity tag attached at two or more sites.

Schmidt, Jurgen G. (Los Alamos, NM); Boyer, Anne E. (Atlanta, GA); Kalb, Suzanne R. (Atlanta, GA); Moura, Hercules (Tucker, GA); Barr, John R. (Suwannee, GA); Woolfitt, Adrian R. (Atlanta, GA)

2009-11-03T23:59:59.000Z

160

Enzymatic Digestion in Aqueous-Organic Solvents: A Mass Spectrometry-Based Approach in Monitoring Protein Conformation Changes  

E-Print Network (OSTI)

The three dimensional structure of a protein is important for its function. When misfolded, a protein may be rendered inactive or adapt a conformation that could be toxic. Studying protein folding requires an understanding of protein conformation. Traditionally, protein conformation has been studied using x-ray crystallography and nuclear magnetic resonance (NMR). X-ray crystallography is limited in the analysis of crystallized proteins and is computationally intensive. NMR deals with proteins in solution but reports only an average of conformation and the technique severely suffers from spectral overlapping due to the thousands of resonances of the protein. More recently, mass spectrometry has been employed not only to elucidate primary structures but also gather information on the three-dimensional conformation of proteins. In this study, a mass spectrometric-based approach is used to study the changes in conformation of cytochrome c and the green fluorescent protein when subjected to aqueous-organic solvent systems. The technique involved trypsin digestion and generation of peptide mass maps. For cytochrome c, the experiments were done with ethanol, methanol and acetonitrile to gain insights on naturation and denaturation. An apparent solvent effect to the rate of digestion and propensity for missed cleavages attributed to weakening of hydrophobic interactions and strengthening of intramolecular hydrogen bonding was observed. For the green fluorescent protein, sulfolane, a known supercharging agent, was used to gain insights on the effect of supercharging to protein conformation. Addition of 2.0% sulfolane shifted the charge state envelope of the protein towards lower m/z while adding lower amounts of sulfolane enhanced lower charge states while broadening the charge state envelope. The time course study showed different patterns of digestion dependent on solvent conditions implying changes in conformation. Furthermore, absorbance and fluorescence measurements suggested that addition of sulfolane protects the fluorophore from quenching. The activity of trypsin is not affected by addition of low amounts of sulfolane.

Tuvilla, Mavreen Rose

2013-05-01T23:59:59.000Z

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.


161

Gas chromatograph-mass spectrometer (GC/MS) system for quantitative analysis of reactive chemical compounds  

DOE Patents (OSTI)

Described is a new gas chromatograph-mass spectrometer (GC/MS) system and method for quantitative analysis of reactive chemical compounds. All components of such a GC/MS system external to the oven of the gas chromatograph are programmably temperature controlled to operate at a volatilization temperature specific to the compound(s) sought to be separated and measured.

Grindstaff, Quirinus G. (Oak Ridge, TN)

1992-01-01T23:59:59.000Z

162

Development of a detection method for {244}Pu by resonance ionization mass spectrometry.  

Science Conference Proceedings (OSTI)

The long-lived actinide {sup 244}Pu (t{sub 1/2} = 81 Myr) is expected to be present in the Interstellar Medium from fresh r-process nucleosynthesis or in direct ejecta from supernovae. Deposition onto Earth may result in traces of live {sup 244}Pu in suitable reservoirs. We are developing a method for {sup 244}Pu detection based on resonance ionization mass spectroscopy. Using Gd as a proxy, we determine an overall efficiency of 0.5% in conditions applicable to the detection of Pu, and present preliminary results on Pu detection.

Ofan, A.; Ahmad, I.; Greene, J. P.; Paul, M.; Savina, M. R. (Materials Science Division); ( PHY); (Hebrew Univ.)

2006-07-01T23:59:59.000Z

163

Subscriber access provided by Indiana University Analytical Chemistry is published by the American Chemical Society. 1155  

E-Print Network (OSTI)

Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Article Ion Mobility Spectrometry permission to reproduce figures and/or text from this article #12;Ion Mobility Spectrometry/Mass Spectrometry, including medical devices and food storage, and therefore requires a new generation of technology

Clemmer, David E.

164

Electrodeposition of Technetium on Platinum for Thermal Ionization Mass Spectrometry (TIMS)  

Science Conference Proceedings (OSTI)

A novel device has been fabricated for the electrodeposition of technetium metal onto platinum filaments for thermal ionization mass spectrometric (TIMS) measurements. The ability of the device to focus the deposition to diameters of hundreds of micrometers on pre-mounted TIMS filaments coupled with the ease of use and simplicity of design permit for an extremely sensitive yet economical TIMS filament loading technique. Electrodeposition parameters were varied in order to maximize deposition efficiency. X-ray photoelectron spectroscopy (XPS) was used to confirm and characterize the technetium deposit. The technetium is deposited in the metallic state, although surface oxides in the 4+ and 7+ state form readily. Initial TIMS measurements of the electrodeposited technetium in the presence of a barium sulfate ionization enhancer show potential for excellent sensitivity.

Engelmann, Mark D.; Metz, Lori A.; Delmore, James E.; Engelhard, Mark H.; Ballou, Nathan E.

2008-05-15T23:59:59.000Z

165

Determination of total chlorine and bromine in solid wastes by sintering and inductively coupled plasma-sector field mass spectrometry  

Science Conference Proceedings (OSTI)

A sample preparation method based on sintering, followed by analysis by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS) for the simultaneous determination of chloride and bromide in diverse and mixed solid wastes, has been evaluated. Samples and reference materials of known composition were mixed with a sintering agent containing Na{sub 2}CO{sub 3} and ZnO and placed in an oven at 560 deg. C for 1 h. After cooling, the residues were leached with water prior to a cation-exchange assisted clean-up. Alternatively, a simple microwave-assisted digestion using only nitric acid was applied for comparison. Thereafter the samples were prepared for quantitative analysis by ICP-SFMS. The sintering method was evaluated by analysis of certified reference materials (CRMs) and by comparison with US EPA Method 5050 and ion chromatography with good agreement. Median RSDs for the sintering method were determined to 10% for both chlorine and bromine, and median recovery to 96% and 97%, respectively. Limits of detection (LODs) were 200 mg/kg for chlorine and 20 mg/kg for bromine. It was concluded that the sintering method is suitable for chlorine and bromine determination in several matrices like sewage sludge, plastics, and edible waste, as well as for waste mixtures. The sintering method was also applied for determination of other elements present in anionic forms, such as sulfur, arsenic, selenium and iodine.

Osterlund, Helene [Division of Applied Geology, Lulea University of Technology, S-971 87 Lulea (Sweden); ALS Scandinavia AB, ALS Laboratory Group, Aurorum 10, S-977 75 Lulea (Sweden)], E-mail: Helene.Osterlund@alsglobal.com; Rodushkin, Ilia [Division of Applied Geology, Lulea University of Technology, S-971 87 Lulea (Sweden); ALS Scandinavia AB, ALS Laboratory Group, Aurorum 10, S-977 75 Lulea (Sweden); Ylinenjaervi, Karin; Baxter, Douglas C. [ALS Scandinavia AB, ALS Laboratory Group, Aurorum 10, S-977 75 Lulea (Sweden)

2009-04-15T23:59:59.000Z

166

Oxidative degradation of bis (2,4,4-trimethylpentyl) dithiophosphinic acid in nitric acid studied by electrospray ionization mass spectrometry  

SciTech Connect

Samples of bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex-301) were analyzed using direct infusion electrospray ionization mass spectrometry. Positive ion spectra of standard and stereo-pure acids displayed ions typical of the unmodified compound, cationized monomeric and dimeric cluster ion species. In addition, a significant ions 2 u less than the dimeric clusters were seen, that correspond to an oxidatively coupled species designated Cyx2 that is observed as H- or Na-cationized species in the electrospray analyses. Based on uncorrected ion intensities, Cyx2 is estimated to account for about 20% of the total in the standard materials. When samples that were contacted with 3 M HNO3 were analyzed, the positive ion spectrum consisted nearly entirely of ions derived from the oxidatively coupled product, indicating that the acid promotes coupling. The negative ion spectra of the standard acids consisted nearly entirely of the conjugate base that is formed by deprotonation of the acids, and cluster ions containing multiple acid molecules. The negative spectra of the HNO3-contacted samples also contained the conjugate base of the unmodified acid, but also two other species that correspond to the dioxo- and perthio- derivatives. It is concluded that HNO3 contact causes significant oxidation, forming at least three major products, Cyx2, the perthio-acid, and the dioxo-acid.

G. S. Groenewold; D. R. Peterman

2012-10-01T23:59:59.000Z

167

Detection of triclocarban and two co-contaminating chlorocarbanilides in US aquatic environments using isotope dilution liquid chromatography tandem mass spectrometry  

SciTech Connect

The antimicrobial compound triclocarban (TCC; 3,4,4'-trichlorocarbanilide; CAS-bar 101-20-2) is a high-production-volume chemical, recently suggested to cause widespread contamination of US water resources. To test this hypothesis, we developed an isotope dilution liquid chromatography electrospray ionization tandem mass spectrometry method for ultratrace analysis of TCC (0.9ng/L detection limit) and analyzed low-volume water samples (200mL) along with primary sludge samples from across the United States. All river water samples (100%) collected downstream of wastewater treatment plants had detectable levels of TCC, as compared to 56% of those taken upstream. Concentrations of TCC (mean+/-standard deviation) downstream of sewage treatment plants (84+/-110ng/L) were significantly higher (P<0.05; Wilcoxon rank sum test) than those of samples taken upstream (12+/-15ng/L). Compared to surface water, mean TCC concentrations found in dried, primary sludge obtained from municipal sewage treatment plants in five states were six orders of magnitude greater (19,300+/-7100{mu}g/kg). Several river samples contained a co-contaminant, identified based on its chromatographic retention time, molecular base ion, and MS/MS fragmentation behavior as 4,4'-dichlorocarbanilide (DCC; CAS-bar 1219-99-4). In addition to TCC and DCC, municipal sludge contained a second co-contaminant, 3,3',4,4'-tetrachlorocarbanilide (TetraCC; CAS-bar 4300-43-0). Both newly detected compounds were present as impurities (0.2%{sub w/w} each) in technical grade TCC (99%). Application of the new method for chlorocarbanilide analysis yielded TCC occurrence data for 13 US states, confirmed the role of sewage treatment plants as environmental inputs of TCC, and identified DCC and TetraCC as previously unrecognized pollutants released into the environment alongside TCC.

Sapkota, Amir [Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, Johns Hopkins University Center for Water and Health, Baltimore, MD 21205-2103 (United States); Heidler, Jochen [Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, Johns Hopkins University Center for Water and Health, Baltimore, MD 21205-2103 (United States); Halden, Rolf U. [Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, Johns Hopkins University Center for Water and Health, Baltimore, MD 21205-2103 (United States)]. E-mail: rhalden@jhsph.edu

2007-01-15T23:59:59.000Z

168

B American Society for Mass Spectrometry, 2011 DOI: 10.1007/s13361-011-0217-6  

E-Print Network (OSTI)

Abstract A new, two-dimensional overtone mobility spectrometry (OMS-OMS) instrument is described Spectrom. (2011) 22:2049Y2060 RESEARCH ARTICLE Overtone Mobility Spectrometry: Part 4. OMS-OMS Analyses for the analysis of complex peptide mixtures. OMS separations are based on the differences in mobilities of ions

Clemmer, David E.

169

B American Society for Mass Spectrometry, 2011 DOI: 10.1007/s13361-011-0087-y  

E-Print Network (OSTI)

Spectrom. (2011) 22:804Y816 RESEARCH ARTICLE Overtone Mobility Spectrometry: Part 3. On the Origin of Peaks The origin of non-integer overtone peaks in overtone mobility spectrometry (OMS) spectra is investigated of peaks. The new equation makes it possible to determine collision cross sections from any OMS peak

Clemmer, David E.

170

Fundamental studies of the plasma extraction and ion beam formation processes in inductively coupled plasma mass spectrometry  

SciTech Connect

The fundamental and practical aspects are described for extracting ions from atmospheric pressure plasma sources into an analytical mass spectrometer. Methodologies and basic concepts of inductively coupled plasma mass spectrometry (ICP-MS) are emphasized in the discussion, including ion source, sampling interface, supersonic expansion, slumming process, ion optics and beam focusing, and vacuum considerations. Some new developments and innovative designs are introduced. The plasma extraction process in ICP-MS was investigated by Langmuir measurements in the region between the skimmer and first ion lens. Electron temperature (T{sub e}) is in the range 2000--11000 K and changes with probe position inside an aerosol gas flow. Electron density (n{sub e}) is in the range 10{sup 8}--10{sup 10} {sup {minus}cm }at the skimmer tip and drops abruptly to 10{sup 6}--10{sup 8} cm{sup {minus}3} near the skimmer tip and drops abruptly to 10{sup 6}--10{sup 8} cm{sup {minus}3} downstream further behind the skimmer. Electron density in the beam leaving the skimmer also depends on water loading and on the presence and mass of matrix elements. Axially resolved distributions of electron number-density and electron temperature were obtained to characterize the ion beam at a variety of plasma operating conditions. The electron density dropped by a factor of 101 along the centerline between the sampler and skimmer cones in the first stage and continued to drop by factors of 10{sup 4}--10{sup 5} downstream of skimmer to the entrance of ion lens. The electron density in the beam expansion behind sampler cone exhibited a 1/z{sup 2} intensity fall-off (z is the axial position). An second beam expansion originated from the skimmer entrance, and the beam flow underwent with another 1/z{sup 2} fall-off behind the skimmer. Skimmer interactions play an important role in plasma extraction in the ICP-MS instrument.

Niu, Hongsen

1995-02-10T23:59:59.000Z

171

Interlaboratory Validation of EPA 1600 Series Methods: Draft EPA Method 1638 for Analysis of Metals in Water by Inductively Coupled Plasma -- Mass Spectrometry (ICP-MS)  

Science Conference Proceedings (OSTI)

Federal and state permits are requiring wastewater dischargers to monitor for ever lower concentrations of trace metals, in some cases at levels that may preclude reliable measurement. In this joint EPA-EPRI interlaboratory data collection effort, eight laboratories evaluated draft EPA Method 1638: Determination of Trace Elements in Ambient Water by Inductively Coupled Plasma-Mass Spectrometry. This method is intended for the analysis of low levels (parts per trillion) of antimony, cadmium, copper, lead,...

2000-11-27T23:59:59.000Z

172

Competitive fragmentation pathways of acetic acid dimer explored by synchrotron VUV photoionization mass spectrometry and electronic structure calculations  

Science Conference Proceedings (OSTI)

In present study, photoionization and dissociation of acetic acid dimers have been studied with the synchrotron vacuum ultraviolet photoionization mass spectrometry and theoretical calculations. Besides the intense signal corresponding to protonated cluster ions (CH{sub 3}COOH){sub n}{center_dot}H{sup +}, the feature related to the fragment ions (CH{sub 3}COOH)H{sup +}{center_dot}COO (105 amu) via {beta}-carbon-carbon bond cleavage is observed. By scanning photoionization efficiency spectra, appearance energies of the fragments (CH{sub 3}COOH){center_dot}H{sup +} and (CH{sub 3}COOH)H{sup +}{center_dot}COO are obtained. With the aid of theoretical calculations, seven fragmentation channels of acetic acid dimer cations were discussed, where five cation isomers of acetic acid dimer are involved. While four of them are found to generate the protonated species, only one of them can dissociate into a C-C bond cleavage product (CH{sub 3}COOH)H{sup +}{center_dot}COO. After surmounting the methyl hydrogen-transfer barrier 10.84 {+-} 0.05 eV, the opening of dissociative channel to produce ions (CH{sub 3}COOH){sup +} becomes the most competitive path. When photon energy increases to 12.4 eV, we also found dimer cations can be fragmented and generate new cations (CH{sub 3}COOH){center_dot}CH{sub 3}CO{sup +}. Kinetics, thermodynamics, and entropy factors for these competitive dissociation pathways are discussed. The present report provides a clear picture of the photoionization and dissociation processes of the acetic acid dimer in the range of the photon energy 9-15 eV.

Guan Jiwen; Hu Yongjun; Zou Hao [MOE Key laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631 (China); Cao Lanlan; Liu Fuyi; Shan Xiaobin; Sheng Liusi [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029 (China)

2012-09-28T23:59:59.000Z

173

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

E-Print Network (OSTI)

Separations coupled to mass spectrometry (MS) are widely used for large-scale protein identification in order to reduce the adverse effects of analyte ion suppression, increase the dynamic range, and as a deconvolution technique for complex datasets typical of cellular protein complements. In this work, matrix assisted laser desorption-ionization is coupled with ion mobility (IM) separation for the analysis of biological molecules. The utility of liquid-phase separations coupled to MS lies in the orthogonality of the two separation dimensions for all analytes. The data presented in this work illustrates that IM-MS relies on the correlation between separation dimensions for different classes (either structural or chemical) of analyte ions to obtain a useful separation. For example, for a series of peptide ions of increasing mass-to-charge (m/z) a plot drift time in the IM drift cell vs. m/z increases in a near-linear fashion, but DNA or lipids having similar m/z values will have very different IM drift time-m/z relationships, thus drift time vs. m/z can be used as a qualitative tool for compound class identification. In addition, IM-MS is applied to the analysis of large peptide datasets in order to determine the peak capacity of the method for bottom-up experiments in proteomics, and it is found that IM separation increases the peak capacity of an MS-only experiment by a factor of 5-10. The population density of the appearance area for peptides is further characterized in terms of the gas-phase structural propensities for tryptic peptide ions. It is found that a small percentage (~3%) of peptide sequences form extended (i.e., helical or ?-sheet type) structures in the gas-phase, thus influencing the overall appearance area for peptide ions. Furthermore, the ability of IM-MS to screen for the presence of phosphopeptides is characterized, and it is found that post translationally modified peptides populate the bottom one-half to one-third of the total appearance area for peptide ions. In general, the data presented in this work indicates that IM-MS offers dynamic range and deconvolution capabilities comparable to liquid-phase separation techniques coupled to MS on a time scale (ms) that is fully compatible to current MS, including TOF-MS, technology.

Ruotolo, Brandon Thomas

2003-05-01T23:59:59.000Z

174

Characterization of human expired breath by solid phase microextraction and analysis using gas chromatography-mass spectrometry and differential mobility spectrometry  

E-Print Network (OSTI)

Breath analysis has potential to become a new medical diagnostic modality. In this thesis, a method for the analysis of human expired breath was developed using gas chromatography-mass spectroscopy. It was subsequently ...

Merrick, William (William F. W.)

2005-01-01T23:59:59.000Z

175

Nano-Domain Analysis Via Massive Cluster Secondary Ion Mass Spectrometry in the Event-by-Event Mode  

E-Print Network (OSTI)

Secondary ion mass spectrometry (SIMS) is a surface analysis technique which characterizes species sputtered by an energetic particle beam. Bombardment with cluster projectiles offers the following notable advantages over bombardment with atomic ions or small clusters: enhanced emission of molecular ions, low damage cross-section, and reduced molecular fragmentation. Additionally, in the case of Au4004 and C60 impacts, desorption originates from nanometric volumes. These features make clusters useful probes to obtain molecular information from both nano-objects and nano-domains. The "event-by-event bombardment/detection mode" probes nano-objects one-at-a-time, while collecting and storing the corresponding secondary ion (SI) information. Presented here are the first experiments where free-standing nano-objects were bombarded with keV projectiles of atomic to nanoparticle size. The objects are aluminum nano-whiskers, 2 nm in diameter and ~250 nm in length. Au4004 has a diameter of ~2 nm, comparable to the nominal diameter of the nanowhiskers. There are notable differences in the SI response from sample volumes too small for full projectile energy deposition. The whisker spectra are dominated by small clusters?the most abundant species being AlO- and AlO2-. Bulk samples have larger yields for AlO2- than for AlO-, while this trend is reversed in whisker samples. Bulk samples give similar abundances of large SI clusters, while whisker samples give an order of magnitude lower yield of these SIs. Effective yields were calculated in order to determine quantitative differences between the nano-objects and bulk samples. The characterization of individual nano-objects from a mixture is demonstrated with negatively charged polymer spheres that are attracted to and retained by the nano-whiskers. The spheres are monodisperse polystyrene nanoparticles (30nm diameter). Our results show that the event-by-event mode can provide information on the nature, size, relative location, and abundance of nano-objects in the field of view. This study presents the first evidence of quantitative molecular information originating from nano-object mixtures. Biologically relevant systems (solid-supported lipid bilayers) were also characterized using Au5 , Au4004 and C60 . Organization-dependent SI emission was observed for phosphocholine bilayers. Lipid domain formation was also investigated in bilayers formed from cholesterol and a mixed lipid system. Trends in the correlation coefficient suggest that cholesterol segregates from the surrounding lipid environment during raft formation.

Pinnick, Veronica Tiffany

2009-12-01T23:59:59.000Z

176

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

177

Application of a trochoidal electron monochromator/mass spectrometer system to the study of environmental chemicals  

SciTech Connect

A trochoidal electron monochromator has been interfaced to a mass spectrometer to perform electron capture negative ion mass spectrometric (ECNIMS) analyses of environmentally relevant chemicals. The kinetic energy of the electron beam can be varied from 0.025 to 30 eV under computer control. No reagent gas is used to moderate the electron energies. An electron energy spread of +/- 0.1 to +/- 0.4 eV full width at half-maximum (fwhm) can readily be obtained at a transmitted current of 2 x 10(-6) A, improving to +/- 0.07 eV at 5 x 10(-7) A. Comparisons of ECNI results from the electron monochromator/mass spectrometer system with those from a standard instrument that uses a moderating gas show similar spectra for heptachlor but not for the s-triazine herbicides, as for example, atrazine. This compound shows numerous adduct ions by standard ECNIMS that are eliminated by using the electron monochromator to generate the mass spectra. Isomeric tetrachlorodibenzo-p-dioxins show distinct differences in the electron energies needed to produce the maximum amount of parent and fragment anions. Multiple resonance states resulting in stable radical anions (M.-) are easily observed for nitrobenzene and for polycyclic aromatic hydrocarbons. Ionic products of dissociative electron capture invariably occur from several resonance states.

Laramee, J.A.; Kocher, C.A.; Deinzer, M.L. (Oregon State Univ., Corvallis (United States))

1992-10-15T23:59:59.000Z

178

Feasibility of the detection of trace elements in particulate matter using online High-Resolution Aerosol Mass Spectrometry  

SciTech Connect

The feasibility of using an online thermal-desorption electron-ionization high-resolution aerosol mass spectrometer (AMS) for the detection of particulate trace elements was investigated analyzing data from Mexico City obtained during the MILAGRO 2006 field campaign, where relatively high concentrations of trace elements have been reported. This potential application is of interest due to the real-time data provided by the AMS, its high sensitivity and time resolution, and the widespread availability and use of this instrument. High resolution mass spectral analysis, isotopic ratios, and ratios of different ions containing the same elements are used to constrain the chemical identity of the measured ions. The detection of Cu, Zn, As, Se, Sn, and Sb is reported. There was no convincing evidence for the detection of other trace elements commonly reported in PM. The elements detected tend to be those with lower melting and boiling points, as expected given the use of a vaporizer at 600oC in this instrument. Operation of the AMS vaporizer at higher temperatures is likely to improve trace element detection. The detection limit is estimated at approximately 0.3 ng m-3 for 5-min of data averaging. Concentration time series obtained from the AMS data were compared to concentration records determined from offline analysis of particle samples from the same times and locations by ICP (PM2.5) and PIXE (PM1.1 and PM0.3). The degree of correlation and agreement between the three instruments (AMS, ICP, and PIXE) varied depending on the element. The AMS shows promise for real-time detection of some trace elements, although additional work including laboratory calibrations with different chemical forms of these elements are needed to further develop this technique and to understand the differences with the ambient data from the other techniques. The trace elements peaked in the morning as expected for primary sources, and the many detected plumes suggest the presence of multiple point sources, probably industrial, in Mexico City which are variable in time and space, in agreement with previous studies.

Salcedo, D.; Laskin, Alexander; Shutthanandan, V.; Jimenez, Jose L.

2012-08-10T23:59:59.000Z

179

Synergistic use of Knudsen effusion quadrupole mass spectrometry, solid-state galvanic cell and differential scanning calorimetry for thermodynamic studies on lithium aluminates  

SciTech Connect

Three ternary oxides LiAl{sub 5}O{sub 8}(s), LiAlO{sub 2}(s) and Li{sub 5}AlO{sub 4}(s) in the system Li-Al-O were prepared by solid-state reaction route and characterized by X-ray powder diffraction method. Equilibrium partial pressure of CO{sub 2}(g) over the three-phase mixtures {l_brace}LiAl{sub 5}O{sub 8}(s)+Li{sub 2}CO{sub 3}(s)+5Al{sub 2}O{sub 3}(s){r_brace}, {l_brace}LiAl{sub 5}O{sub 8}(s)+5LiAlO{sub 2}(s)+2Li{sub 2}CO{sub 3}(s){r_brace} and {l_brace}LiAlO{sub 2}(s)+Li{sub 5}AlO{sub 4}(s)+2Li{sub 2}CO{sub 3}(s){r_brace} were measured using Knudsen effusion quadrupole mass spectrometry (KEQMS). Solid-state galvanic cell technique based on calcium fluoride electrolyte was used to determine the standard molar Gibbs energies of formations of these aluminates. The standard molar Gibbs energies of formation of these three aluminates calculated from KEQMS and galvanic cell measurements were in good agreement. Heat capacities of individual ternary oxides were measured from 127 to 868 K using differential scanning calorimetry. Thermodynamic tables representing the values of {delta}{sub f}H{sup 0}(298.15 K), S{sup 0}(298.15 K) S{sup 0}(T), C{sub p}{sup 0}(T), H{sup 0}(T), {l_brace}H{sup 0}(T)-H{sup 0}(298.15 K){r_brace}, G{sup 0}(T), {delta}{sub f}H{sup 0}(T), {delta}{sub f}G{sup 0}(T) and free energy function (fef) were constructed using second law analysis and FACTSAGE thermo-chemical database software. - Graphical abstract: Comparison of {delta}{sub f}G{sub m}{sup 0} of ternary oxides determined from KEQMS and solid-state galvanic cell techniques. (O) KEQMS, (9632;) solid-state galvanic cell and solid line: combined fit of both the experimental data.

Rakshit, S.K. [Product Development Section, Radiochemistry and Isotope Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)], E-mail: swarupkr@barc.gov.in; Naik, Y.P.; Parida, S.C.; Dash, Smruti; Singh, Ziley; Sen, B.K.; Venugopal, V. [Product Development Section, Radiochemistry and Isotope Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

2008-06-15T23:59:59.000Z

180

Isotope ratio analysis of actinides, fission products, and geolocators by high-efficiency multi-collector thermal ionization mass spectrometry  

SciTech Connect

A ThermoFisher 'Triton' multi-collector thermal ionization mass spectrometer (MC-TIMS) was evaluated for trace and ultra-trace level isotoperatioanalysis of actinides (uranium, plutonium, and americium), fission products and geolocators (strontium, cesium, and neodymium). Total efficiencies (atoms loaded to ions detected) of up to 0.5-2% for U, Pu, and Am, and 1-30% for Sr, Cs, and Nd can be reported employing resin bead load techniques onto flat ribbon Re filaments or resin beads loaded into a millimeter-sized cavity drilled into a Re rod. This results in detection limits of <0.1 fg (10{sup 4} atoms to 10{sup 5} atoms) for {sup 239-242+244}Pu, {sup 233+236}U, {sup 241-243}Am, {sup 89,90}Sr, and {sup 134,135,137}Cs, and {le} 1 pg for natural Nd isotopes (limited by the chemical processing blank) using a secondary electron multiplier (SEM) or multiple-ion counters (MICs). Relative standard deviations (RSD) as small as 0.1% and abundance sensitivities of 1 x 10{sup 6} or better using a SEM are reported here. Precisions of RSD {approx} 0.01-0.001% using a multi-collector Faraday cup array can be achieved at sub-nanogram concentrations for strontium and neodymium and are suitable to gain crucial geolocation information. The analytical protocols reported herein are of particular value for nuclear forensic and nuclear safeguard applications.

Bürger, Stefan [New Brunswick Laboratory, Argonne, IL; Riciputi, Lee R [Los Alamos National Laboratory (LANL); Bostick, Debra A [ORNL; Turgeon, Steven [University of Alberta, Edmondton, Canada; McBay, Eddie H [ORNL; Lavelle, Mark [ORNL

2009-01-01T23:59:59.000Z

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181

Quark-mass dependence of the three-flavor QCD phase diagram at zero and imaginary chemical potential: Model prediction  

Science Conference Proceedings (OSTI)

We draw the three-flavor phase diagram as a function of light- and strange-quark masses for both zero and imaginary quark-number chemical potential, using the Polyakov-loop extended Nambu-Jona-Lasinio model with an effective four-quark vertex depending on the Polyakov loop. The model prediction is qualitatively consistent with 2+1 flavor lattice QCD prediction at zero chemical potential and with degenerate three-flavor lattice QCD prediction at imaginary chemical potential.

Sasaki, Takahiro; Sakai, Yuji; Yahiro, Masanobu [Department of Physics, Graduate School of Sciences, Kyushu University, Fukuoka 812-8581 (Japan); Kouno, Hiroaki [Department of Physics, Saga University, Saga 840-8502 (Japan)

2011-11-01T23:59:59.000Z

182

International Journal of Mass Spectrometry 309 (2012) 154160 Contents lists available at SciVerse ScienceDirect  

E-Print Network (OSTI)

.elsevier.com/locate/ijms Extracted fragment ion mobility distributions: A new method for complex mixture analysis Sunyoung Lee, Zhiyu isomers a b s t r a c t A new method is presented for constructing ion mobility distributions of precursor 2011 Available online 22 September 2011 Keywords: Ion mobility spectrometry Collision

Clemmer, David E.

183

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

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

184

Chemical process optimization and pollution prevention via mass and property integration  

E-Print Network (OSTI)

The process industries such as petrochemicals, chemicals and pharmaceuticals, among others, consume large amounts of material and energy resources. These industries are also characterized by generating enormous amounts of waste that significantly contribute to the pollution of the environment. Integrated process design is a very effective technique in conserving process resources and preventing pollution. The design and environmental constraints may involve a variety of component- and property-based restrictions. To date, most techniques have been developed to handle process constraints which is either composition-based (via mass integration) or property-based. No work has been reported to handle the synthesis of resource conservation network that is governed by both constraints. The objective of this work is to develop a systematic and cost-effective design technique that is aimed at minimizing the consumption of fresh resources and the discharge of pollutants simultaneously. Because of the nature of the component- and property-based constraints, this approach is based on mass and property integration and takes into account the process constraints and also environmental regulations. In this research work, a new approach has been developed to simultaneously address component-based recycle constraints as well as property-based discharge constraints. The proposed optimization technique is intended to minimize the consumption of fresh resources, the pollutant content in the waste streams, and the operational and waste treatment costs. Additionally, a mixed-integer nonlinear programming (MINLP) formulation is solved for a case study of phenol production from cumene hydroperoxyde to illustrate the new problem and devised solution algorithm.

Hortua, Ana Carolina

2007-05-01T23:59:59.000Z

185

Multiplexed Ion Mobility Spectrometry-Orthogonal Time-of ...  

Multiplexed Ion Mobility Spectrometry-Orthogonal Time-of-Flight Mass Spectrometry Mikhail E. Belov, ... in the multiplexed IMS-TOF MS experiments ...

186

Determination of the {sup 22}Ne{sub nucl}/{sup 4}He{sub rad} ratio in natural uranium-rich fluorite by mass spectrometry  

Science Conference Proceedings (OSTI)

A determination by noble gas mass spectrometry of {sup 22}Ne production through the combined reactions {sup 19}F({alpha},n){sup 22}Na({beta}{sup +}){sup 22}Ne and {sup 19}F({alpha},p){sup 22}Ne on natural calcium fluoride is made for the first time. Six samples of U-rich fluorite from a fluorspar deposit in Mexico were used to determine the {sup 22}Ne{sub nucl}/{sup 4}He{sub rad} ratio generated by the spontaneous decay of U during the last 32 Ma. The obtained ratio (1.33 {+-} 0.11) x10{sup -5} (95% confidence), is compared to other experimental data on natural uranium oxides and theoretical values.

Sole, Jesus; Pi, Teresa [Instituto de Geologia, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, Coyoacan, 04510 Mexico D.F. (Mexico)

2006-10-15T23:59:59.000Z

187

MANTRA: An Integral Reactor Physics Experiment to Infer Actinide Capture Cross-sections from Thorium to Californium with Accelerator Mass Spectrometry  

SciTech Connect

The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectrometry technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am, 244Cm and 248Cm.

G. Youinou; C. McGrath; G. Imel; M. Paul; R. Pardo; F. Kondev; M. Salvatores; G. Palmiotti

2011-08-01T23:59:59.000Z

188

Laser ablation-inductively coupled plasma-mass spectrometry: Examinations of the origins of polyatomic ions and advances in the sampling of particulates  

SciTech Connect

This dissertation provides a general introduction to Inductively coupled plasma-mass spectrometry (ICP-MS) and laser ablation (LA) sampling, with an examination of analytical challenges in the employment of this technique. It discusses the origin of metal oxide ions (MO+) in LA-ICP-MS, as well as the effect of introducing helium and nitrogen to the aerosol gas flow on the formation of these polyatomic interferences. It extends the study of polyatomic ions in LA-ICP-MS to metal argide (MAr+) species, an additional source of possible significant interferences in the spectrum. It describes the application of fs-LA-ICP-MS to the determination of uranium isotope ratios in particulate samples.

Witte, Travis

2011-11-30T23:59:59.000Z

189

Characterization of Diesel Fuel by Chemical Separation Combined with Capillary Gas Chromatography (GC) Isotope Ratio Mass Spectrometry (IRMS)  

Science Conference Proceedings (OSTI)

The purpose of this study was to perform a preliminary investigation of compound-specific isotope analysis (CSIA) of diesel fuels to evaluate whether the technique could distinguish between the diesel samples from different sources/locations. The ability to differentiate or correlate diesel samples could be valuable for detecting fuel tax evasion schemes. Two fractionation techniques were used to isolate the n-alkanes from the fuel. Both ?13C and ?D values for the n-alkanes were then determined by CSIA in each sample. Plots of ?D versus ?13C with sample n-alkane points connected in order of increasing carbon number gave well separated clusters with characteristic shapes for each sample. Principal components analysis (PCA) with ?13C, ?D, or combined ?13C and ?D data on the yielded scores plots that could clearly differentiate the samples, thereby demonstrating the potential of this approach for fingerprinting fuel samples using the ?13C and ?D values.

Harvey, Scott D.; Jarman, Kristin H.; Moran, James J.; Sorensen, Christina M.; Wright, Bob W.

2011-09-15T23:59:59.000Z

190

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

E-Print Network (OSTI)

expected for K-biomass and automobile combustion particles [Arabia: Biomass/biofuel burning and fossil fuel combustion,or coal combustion. The fly ash does not resemble K-biomass

Spencer, Matthew Todd

2007-01-01T23:59:59.000Z

191

B American Society for Mass Spectrometry, 2011 DOI: 10.1007/s13361-011-0168-y  

E-Print Network (OSTI)

with collision-induced dissociation MS/MS. Anal. Sci. 25, 985­ 988 (2009) 15. Williams, J.P., Grabenauer, MHz). Periodically, ion packets are released in short (150 s-wide) pulses into a ~3 m long stacked ring) m/z measurement. Roughly 102 ­103 mass spectra are collected per IMS experiment, allowing drift time

Clemmer, David E.

192

Devices for collecting chemical compounds  

SciTech Connect

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 a fixed surface 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

2013-12-24T23:59:59.000Z

193

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

Science Conference Proceedings (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

194

Chemical differentiation in regions of high mass star formation II. Molecular multiline and dust continuum studies of selected objects  

E-Print Network (OSTI)

The aim of this study is to investigate systematic chemical differentiation of molecules in regions of high mass star formation. We observed five prominent sites of high mass star formation in HCN, HNC, HCO+, their isotopes, C18O, C34S and some other molecular lines, for some sources both at 3 and 1.3 mm and in continuum at 1.3 mm. Taking into account earlier obtained data for N2H+ we derive molecular abundances and physical parameters of the sources (mass, density, ionization fraction, etc.). The kinetic temperature is estimated from CH3C2H observations. Then we analyze correlations between molecular abundances and physical parameters and discuss chemical models applicable to these species. The typical physical parameters for the sources in our sample are the following: kinetic temperature in the range ~ 30-50 K (it is systematically higher than that obtained from ammonia observations and is rather close to dust temperature), masses from tens to hundreds solar masses, gas densities ~ 10^5 cm^{-3}, ionization...

Zinchenko, I; Pirogov, L

2009-01-01T23:59:59.000Z

195

Determination of the Relative Amount of Fluorine in Uranium Oxyfluoride Particles using Secondary Ion Mass Spectrometry and Optical Spectroscopy  

Science Conference Proceedings (OSTI)

Both nuclear forensics and environmental sampling depend upon laboratory analysis of nuclear material that has often been exposed to the environment after it has been produced. It is therefore important to understand how those environmental conditions might have changed the chemical composition of the material over time, particularly for chemically sensitive compounds. In the specific case of uranium enrichment facilities, uranium-bearing particles stem from small releases of uranium hexafluoride, a highly reactive gas that hydrolyzes upon contact with moisture from the air to form uranium oxyfluoride (UO{sub 2}F{sub 2}) particles. The uranium isotopic composition of those particles is used by the International Atomic Energy Agency (IAEA) to verify whether a facility is compliant with its declarations. The present study, however, aims to demonstrate how knowledge of time-dependent changes in chemical composition, particle morphology and molecular structure can contribute to an even more reliable interpretation of the analytical results. We prepared a set of uranium oxyfluoride particles at the Institute for Reference Materials and Measurements (IRMM, European Commission, Belgium) and followed changes in their composition, morphology and structure with time to see if we could use these properties to place boundaries on the particle exposure time in the environment. Because the rate of change is affected by exposure to UV-light, humidity levels and elevated temperatures, the samples were subjected to varying conditions of those three parameters. The NanoSIMS at LLNL was found to be the optimal tool to measure the relative amount of fluorine in individual uranium oxyfluoride particles. At PNNL, cryogenic laser-induced time-resolved U(VI) fluorescence microspectroscopy (CLIFS) was used to monitor changes in the molecular structure.

Kips, R; Kristo, M J; Hutcheon, I D; Amonette, J; Wang, Z; Johnson, T; Gerlach, D; Olsen, K B

2009-05-29T23:59:59.000Z

196

Measurement of {sup 63}Ni and {sup 59}Ni by accelerator mass spectrometry using characteristic projectile x-rays  

Science Conference Proceedings (OSTI)

The long-lived isotopes of nickel ({sup 59}Ni, {sup 63}Ni) have current and potential use in a number of applications including cosmic radiation studies, biomedical tracing, characterization of low-level radioactive wastes, and neutron dosimetry. Methods are being developed at LLNL for the routine detection of these isotopes by AMS. One intended application is in Hiroshima dosimetry. The reaction {sup 63}Cu(n,p){sup 63}Ni has been identified as one of a small number of reactions which might be used for the direct determination of the fast neutron fluence emitted by the Hiroshima bomb. AMS measurement of {sup 63}Ni(t{sub 1/2} = 100 y) requires the chemical removal of {sup 63}Cu, which is a stable isobar of {sup 63}Ni. Following the electrochemical separation of Ni from gram-sized copper samples, the Cu concentration is further lowered to Hiroshima hypocenter. For the demonstration samples, the Cu content was chemically reduced by a factor of 10{sup 12} with quantitative retention of {sup 63}Ni. Detection sensitivity (3{sigma}) was {approximately}20 fg {sup 63}Ni in 1 mg Ni carrier ({sup 63}Ni/Ni {approx} 2 x 10{sup -11}). Significant improvements in sensitivity are expected with planned incremental changes in the methods. Preliminary results indicate that a similar sensitivity is achievable for {sup 59}Ni (t{sub 1/2} = 10{sup 5} y).

McAninch, J.E.; Hainsworth, L.J.; Marchetti, A.A. [and others

1996-05-01T23:59:59.000Z

197

Measurement of {sup 63}Ni and {sup 59}Ni by accelerator mass spectrometry using characteristic projectile x-rays  

SciTech Connect

The long-lived isotopes of nickel ({sup 59}Ni, {sup 63}Ni) have current and potential use in a number of applications including cosmic radiation studies, biomedical tracing, characterization of low-level radioactive wastes, and neutron dosimetry. Methods are being developed at LLNL for the routine detection of these isotopes by AMS. One intended application is in Hiroshima dosimetry. The reaction {sup 63}Cu(n,p){sup 63}Ni has been identified as one of a small number of reactions which might be used for the direct determination of the fast neutron fluence emitted by the Hiroshima bomb. AMS measurement of {sup 63}Ni(t{sub 1/2} = 100 y) requires the chemical removal of {sup 63}Cu, which is a stable isobar of {sup 63}Ni. Following the electrochemical separation of Ni from gram-sized copper samples, the Cu concentration is further lowered to < 2 x 10{sup -8} (Cu/Ni) using the reaction of Ni with carbon monoxide to form the gas Ni(CO){sub 4}. The Ni(CO){sub 4} is thermally decomposed directly in sample holders for measurement by AMS. After analysis in the AMS spectrometer, the ions are identified using characteristic projectile x-rays, allowing further rejection of remaining {sup 63}Cu. In a demonstration experiment, {sup 63}Ni was measured in Cu wires (2-20 g) which had been exposed to neutrons from a {sup 252}Cf source. We successfully measured {sup 63}Ni at levels necessary for the measurement of Cu samples exposed near the Hiroshima hypocenter. For the demonstration samples, the Cu content was chemically reduced by a factor of 10{sup 12} with quantitative retention of {sup 63}Ni. Detection sensitivity (3{sigma}) was {approximately}20 fg {sup 63}Ni in 1 mg Ni carrier ({sup 63}Ni/Ni {approx} 2 x 10{sup -11}). Significant improvements in sensitivity are expected with planned incremental changes in the methods. Preliminary results indicate that a similar sensitivity is achievable for {sup 59}Ni (t{sub 1/2} = 10{sup 5} y).

McAninch, J.E.; Hainsworth, L.J.; Marchetti, A.A. [and others

1996-05-01T23:59:59.000Z

198

Analysis of Non-Enzymatically Glycated Peptides: Neutral-Loss Triggered MS3 Versus Multi-Stage Activation Tandem Mass Spectrometry  

Science Conference Proceedings (OSTI)

Non-enzymatic glycation of tissue proteins has important implications in the development of complications of diabetes mellitus. While electron transfer dissociation (ETD) has been shown to outperform collision-induced dissociation (CID) in sequencing glycated peptides by tandem mass spectrometry, ETD instrumentation is not yet available in all laboratories. In this study, we evaluated different advanced CID techniques (i.e., neutral-loss triggered MS3 and multi-stage activation) during LC-MSn analyses of Amadori-modified peptides enriched from human serum glycated in vitro. During neutral-loss triggered MS3 experiments, MS3 scans triggered by neutral-losses of 3 H2O or 3 H2O + HCHO produced similar results in terms of glycated peptide identifications. However, neutral losses of 3 H2O resulted in significantly more glycated peptide identifications during multi-stage activation experiments. Overall, the multi-stage activation approach produced more glycated peptide identifications, while the neutral-loss triggered MS3 approach resulted in much higher specificity. Both techniques offer a viable alternative to ETD for identifying glycated peptides when that method is unavailable.

Zhang, Qibin; Petyuk, Vladislav A.; Schepmoes, Athena A.; Orton, Daniel J.; Monroe, Matthew E.; Yang, Feng; Smith, Richard D.; Metz, Thomas O.

2008-10-15T23:59:59.000Z

199

Detection and Identification of Heme c-Modified Peptides by Histidine Affinity Chromatography, High-Performance Liquid Chromatography-Mass Spectrometry, and Database Searching  

Science Conference Proceedings (OSTI)

Multiheme c-type cytochromes (proteins with covalently attached heme c moieties) play important roles in extracellular metal respiration in dissimilatory metal-reducing bacteria. Liquid chromatography-tandem mass spectrometry-(LC-MS/MS) characterization of c-type cytochromes is hindered by the presence of multiple heme groups, since the heme c modified peptides are typically not observed, or if observed, not identified. Using a recently reported histidine affinity chromatography (HAC) procedure, we enriched heme c tryptic peptides from purified bovine heart cytochrome c, a bacterial decaheme cytochrome, and subjected these samples to LC-MS/MS analysis. Enriched bovine cytochrome c samples yielded three- to six-fold more confident peptide-spectrum matches to heme-c containing peptides than unenriched digests. In unenriched digests of the decaheme cytochrome MtoA from Sideroxydans lithotrophicus ES-1, heme c peptides for four of the ten expected sites were observed by LC-MS/MS; following HAC fractionation, peptides covering nine out of ten sites were obtained. Heme c peptide spiked into E. coli lysates at mass ratios as low as 10-4 was detected with good signal-to-noise after HAC and LC-MS/MS analysis. In addition to HAC, we have developed a proteomics database search strategy that takes into account the unique physicochemical properties of heme c peptides. The results suggest that accounting for the double thioether link between heme c and peptide, and the use of the labile heme fragment as a reporter ion, can improve database searching results. The combination of affinity chromatography and heme-specific informatics yielded increases in the number of peptide-spectrum matches of 20-100-fold for bovine cytochrome c.

Merkley, Eric D.; Anderson, Brian J.; Park, Jea H.; Belchik, Sara M.; Shi, Liang; Monroe, Matthew E.; Smith, Richard D.; Lipton, Mary S.

2012-12-07T23:59:59.000Z

200

Chemical Heterogeneity across Cloud Droplet Size Spectra in Continental and Marine Air Masses  

Science Conference Proceedings (OSTI)

Variations in the chemical composition of cloud droplets of different sizes are predicted in models. Measurements made in natural clouds to verify this prediction are extremely limited, however. During the spring of 1995 and the summers of 1995 ...

Surabi Menon; V. K. Saxena; B. D. Logie

2000-06-01T23:59:59.000Z

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,
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to obtain the most current and comprehensive results.


201

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  

E-Print Network (OSTI)

flows suitable for kinetic studies of chemical reactions infor a chemical reaction in the available kinetic window ofa complex kinetic behavior. The rate of chemical reactions

Soorkia, Satchin

2012-01-01T23:59:59.000Z

202

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

E-Print Network (OSTI)

This thesis addresses the threat of chemical and biological armed ballistic missiles and their neutralization by nuclear methods. The objective of this effort is twofold. The first objective is to develop a justification for using nuclear interceptors in neutralizing chemical and biological weapons (CBW) based on the current CBW threat to the U.S. The second objective is to reproduce a computer model developed at the Lawrence Livermore National Laboratory (LLNL) in 1992 to estimate the effectiveness of low-yield nuclear interceptors to neutralize biological or chemical tactical ballistic missile warheads and to extend the model for high-energy neutrons (20 MeV) to explore the effect of increasing neutron energies. The original model was developed using TARTNP. MCNP4C was the code used to reproduce the model. At least 27 countries now possess - or are in the process of acquiring and developing - ballistic missiles. Furthermore, more than a dozen states are pursuing offensive CBW capabilities, and some have exhibited a willingness to employ them. One particular method of neutralizing biological and chemical ballistic warheads, which has previously been investigated, is by means of nuclear interceptors, i.e., using a low-yield nuclear device to neutralize the weapon by bombarding it with high-energy particles and rendering it ineffective. To investigate the ability of nuclear interceptors to neutralize CBW missiles, a MCNP model was created based on the LLNL data. The results from the new model were compared to the sterilization requirements suggested by LLNL and to the LLNL results. Although there were differences between the two, the MCNP model produced data with the same trend as the LLNL data and all submunitions were given sufficient energy to exceed the sterilization requirements. Finally, a comparison was made of the neutralization capabilities of a fission device, a fusion device, and an advanced neutron source. It was shown that the advanced neutron source, with its 20 MeV neutrons, delivered on average 12 times as much energy per particle to the Sarin as the fission device and 1.6 times as much energy per particle to the Sarin as the fusion device.

McAffrey, Veronica Lynn

2002-01-01T23:59:59.000Z

203

Inorganic Chemical Metrology Homepage  

Science Conference Proceedings (OSTI)

... mass spectrometries as well as nuclear analytical techniques ... to public safety and security include a ... inertial fusion energy (IFE) reactor, the plasma ...

2012-11-19T23:59:59.000Z

204

Quantification of absorption, retention and elimination of two different oral doses of vitamin A in Zambian boys using accelerator mass spectrometry  

SciTech Connect

A recent survey indicated that high-dose vitamin A supplements (HD-VAS) had no apparent effect on vitamin A (VA) status of Zambian children <5 y of age. To explore possible reasons for the lack of response to HD-VAS among Zambian children, we quantified the absorption, retention, and urinary elimination of either a single HDVAS (60 mg) or a smaller dose of stable isotope (SI)-labeled VA (5 mg), which was used to estimate VA pool size, in 3-4 y old Zambian boys (n = 4 for each VA dose). A 25 nCi tracer dose of [{sup 14}C{sub 2}]-labeled VA was co-administered with the HD-VAS or SI-labeled VA, and 24-hr stool and urine samples were collected for 3 and 7 consecutive days, respectively, and 24-hr urine samples at 4 later time points. Accelerator Mass Spectrometry (AMS) was used to measure the cumulative excretion of {sup 14}C in stool and urine 3d after dosing to estimate, respectively, absorption and retention of the VAS and SI-labeled VA. The urinary elimination rate (UER) was estimated by plotting {sup 14}C in urine vs. time, and fitting an exponential equation to the data. Estimates of mean absorption, retention and the UER were 83.8 {+-} 7.1%, 76.3 {+-} 6.7%, and 1.9 {+-} 0.6%/d, respectively, for the HD-VAS and 76.5 {+-} 9.5%, 71.1 {+-} 9.4%, and 1.8 {+-} 1.2%/d, respectively for the smaller dose of SI-labeled VA. Estimates of absorption, retention and the UER did not differ by size of the VA dose administered (P=0.26, 0.40, 0.88, respectively). Estimated absorption and retention were negatively associated with reported fever (P=0.011) and malaria (P =0.010). HD-VAS and SI-labeled VA were adequately absorbed, retained and utilized in apparently healthy Zambian preschool-age boys, although absorption and retention may be affected by recent infections.

Aklamati, E K; Mulenga, M; Dueker, S R; Buchholz, B A; Peerson, J M; Kafwembe, E; Brown, K H; Haskell, M J

2009-10-12T23:59:59.000Z

205

Development and analytical validation of a gas chromatography-mass spectrometry method for the assessment of gastrointestinal permeability and intestinal absorptive capacity in dogs  

E-Print Network (OSTI)

Assessment of gastrointestinal permeability in vivo is considered a suitable method for the evaluation of gastrointestinal mucosal integrity. Probes commonly used include lactulose (L) and rhamnose (R) for the assessment of intestinal permeability, xylose (X) and 3-O-methylglucose (M) for the evaluation of intestinal absorptive capacity, and sucrose (S) for the assessment of gastric permeability. Traditionally, various methods have been used to quantify these markers in the urine after orogastric administration. However, urine collection is difficult and uncomfortable. A protocol based on the analysis of blood samples would be easier to perform. Thus, the aim of the first part of this project was to develop and validate a new gas chromatography-mass spectrometry (GC-MS) method for the quantification of five sugar probes in canine serum. The method was sensitive, accurate, precise, and reproducible for the simultaneous quantification of 5 sugar probes in serum. The aim of the second part of this project was to assess the kinetic profiles of these 5 sugar probes in serum after orogastric administration in dogs and to determine the optimal time point for sample collection. Dogs received a solution containing L (10 g/L), R (10 g/L), X (10 g/L), M (5 g/L), and S (40 g/L) by orogastric intubation. Baseline blood samples were collected. Subsequent timed blood samples were taken for a 24 hours period. Significant changes in serum concentrations of all 5 sugars were detected after administration of the test dose (p<0.0001 for all 5 probes). Serum concentrations of L and R were significantly different from baseline concentrations from 90 to 240 and from 60 to 300 min post dosing respectively, and those of X, M, and S were significantly different from 30 to 240 min after dosing (p<0.05 for all 5 probes). Variations of the mean sugar concentrations of all dogs at 90, 120, and 180 minutes were analyzed using a Kruskal-Wallis test. Based on the results, only two blood samples, one taken at baseline and a second sample obtained between 90 and 180 after dosing, appear to be sufficient for assessment of intestinal permeability and mucosal absorptive capacity using these sugar probes.

Rodriguez Frausto, Heriberto

2008-12-01T23:59:59.000Z

206

Determination of the Tissue Distribution and Excretion by Accelerator Mass Spectrometry of the Nonadecapeptide 14C-Moli1901 in Beagle dogs after Intratracheal Instillation  

SciTech Connect

Administration of {sup 14}C-Moli1901 (duramycin, 2622U90), a 19 amino acid polycyclic peptide by intratracheal instillation (approximately 100 {micro}g) into the left cranial lobe of the lung of beagle dogs resulted in retention of 64% of the dose in the left cranial lobe for up to 28 days. In this study, we used accelerator mass spectrometry (AMS) to quantify Moli901 following administration of only 0.045 {micro}Ci of {sup 14}C-Moli901 per dog. Limits of quantitation of AMS were 0.03 (urine) to 0.3 (feces) ng equiv. Moli1901/g. Whole blood and plasma concentrations of {sup 14}C were <5ng/ml at all times after the dose. Concentrations of {sup 14}C in whole blood and plasma declined over the first day after the dose and rose thereafter, with the rise in plasma concentrations lagging behind those in whole blood. During the first 3 days after the dose, plasma accounted for the majority of {sup 14}C in whole blood, but after that time, plasma accounted for only 25-30% of the {sup 14}C in whole blood. Tissue (left and right caudal lung lobe, liver, kidney, spleen, brain) and bile concentrations were low, always less than 0.25% the concentrations found in the left cranial lung lobe. Approximately 13% of the dose was eliminated in urine and feces in 28 days, with fecal elimination accounting for about 10% of the dose. The data presented here are consistent with that obtained in other species. Moli1901 is slowly absorbed and excreted from the lung, and it does not accumulate in other tissues. Moli1901 is currently in the clinic and has proven to be safe in single dose studies in human volunteers and cystic fibrosis patients by the inhalation route. No information on the disposition of the compound in humans is available. This study in dogs demonstrates the feasibility of obtaining that information using {sup 14}C-Moli1901 and AMS.

Rickert, D E; Dingley, K H; Ubick, E; Dix, K J; Molina, L

2004-07-02T23:59:59.000Z

207

Blend Down Monitoring System Fissile Mass Flow Monitor Implementation at the ElectroChemical Plant, Zelenogorsk, Russia  

SciTech Connect

The implementation plans and preparations for installation of the Fissile Mass Flow Monitor (FMFM) equipment at the ElectroChemical Plant (ECP), Zelenogorsk, Russia, are presented in this report. The FMFM, developed at Oak Ridge National Laboratory, is part of the Blend Down Monitoring System (BDMS), developed for the U.S. Department of Energy Highly Enriched Uranium (HEU) Transparency Implementation Program. The BDMS provides confidence to the United States that the Russian nuclear facilities supplying the lower-assay ({approx}4%) product low enriched uranium (P-LEU) to the United States from down-blended weapons-grade HEU are meeting the nonproliferation goals of the government-to-government HEU Purchase Agreement, signed between the Russian Federation and the United States in 1993. The first BDMS has been operational at Ural Electrochemical Integrated Plant, Novouralsk, since February 1999 and is successfully providing HEU transparency data to the United States. The second BDMS was installed at ECP in February 2003. The FMFM makes use of a set of thermalized californium-252 ({sup 252}Cf) spontaneous neutron sources for a modulated fission activation of the UF{sub 6} gas stream for measuring the {sup 235}U fissile mass flow rate. To do this, the FMFM measures the transport time of the fission fragments created from the fission activation process under the modulated source to the downstream detectors by detecting the delayed gamma rays from the fission fragments. The FMFM provides unattended, nonintrusive measurements of the {sup 235}U mass flow in the HEU, LEU blend stock, and P-LEU process legs. The FMFM also provides the traceability of the HEU flow to the product process leg. This report documents the technical installation requirements and the expected operational characteristics of the ECP FMFM.

Uckan, T.

2005-11-11T23:59:59.000Z

208

Blend Down Monitoring System Fissile Mass Flow Monitor and its Implementation at the Siberian Chemical Enterprise, Seversk, Russia  

SciTech Connect

In this paper the implementation plans and preparations for installation of the Fissile Mass Flow Monitor (FMFM) equipment at the Siberian Chemical Enterprise (SChE), Seversk, Russia, are presented. The FMFM, developed by Oak Ridge National Laboratory, is part of the Blend Down Monitoring System (BDMS) for the U.S. Department of Energy Highly Enriched Uranium (HEU) Transparency Implementation Program. The BDMS provides confidence to the United States that the Russian nuclear facilities supplying the lower assay ({approx}4%) product low enriched uranium (PLEU) to the United States from down-blended weapon-grade HEU are meeting the nonproliferation goals of the government-to-government HEU purchase agreement signed between the Russian Federation and the United States in 1993. The first BDMS has been operational at Ural Electrochemical Integrated Plant, Novouralsk, since February 1999. The second BDMS has been operational at Electro Chemical Plant, Zelenogorsk, since March 2003. These systems are successfully providing HEU transparency data to the United States. The third BDMS was successfully installed on the HEU down-blending tee in the SChE Enrichment Plant in October 2004. The FMFM makes use of a set of thermalized {sup 252}Cf spontaneous neutron sources for modulated fission activation of the UF{sub 6} gas stream for measuring the {sup 235}U fissile mass flow rate. To do this, the FMFM measures the transport time of the fission fragments created from the fission activation process under the modulated source to the downstream detectors by detecting the delayed gamma rays from the fission fragments retained in the flow. The FMFM provides unattended nonintrusive measurements of the {sup 235}U mass flow of the UF{sub 6} gas in the blending tee legs of HEU, the LEU blend stock, and the resulting P-LEU. The FMFM also confirms that highly enriched UF{sub 6} gas identified in the HEU leg flows through the blending tee into the P-LEU leg. This report contains details of the SChE FMFM equipment characteristics as well as the technical installation requirements and the latest measurement results.

Uckan, T

2005-07-28T23:59:59.000Z

209

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

Science Conference Proceedings (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

210

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

SciTech Connect

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

211

Device for collecting chemical compounds and related methods  

SciTech Connect

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

212

Chemical analysis of biomass fast pyrolysis oils  

DOE Green Energy (OSTI)

This paper reviews the development of the field of chemical analysis of biomass fast pyrolysis oils. The techniques applied to pyrolysis oil analysis are reviewed including proximate and ultimate analysis, water (moisture) analysis, and chemical component analysis by various forms of chromatography, solvent separations, and spectrophotometric analyses, like infrared and ultraviolet. Advanced analytical techniques such as nuclear magnetic resonance and molecular beam -- mass spectrometry are also discussed. This paper reviews and compares the methods and the results of the analyses. The advantages and shortcomings of the various methods applied are identified. Comparisons derived from the IEA Round Robin are incorporated.

Elliott, D.C.

1994-09-01T23:59:59.000Z

213

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

214

Mexico City Aerosol Analysis During Milagro Using High Resolution Aerosol Mass Spectrometry at the Urban Supersite (T0) - Part 1: Fine Particle Composition and Organic Source Apportionment.  

E-Print Network (OSTI)

Submicron aerosol was analyzed during the MILAGRO field campaign in March 2006 at the T0 urban supersite in Mexico City with a High-Resolution Aerosol Mass Spectrometer (AMS) and complementary instrumentation. Positive ...

Aiken, A. C.

215

Decomposition of NH3BH3 at sub-ambient pressures: A combined thermogravimetry-differential thermal analysis-mass spectrometry study  

DOE Green Energy (OSTI)

We report a systematic study of the isothermal decomposition of ammonia borane, NH3BH3, at 363 K as a function of argon pressure ranging between 50 and 1040 mbar using thermogravimetry and differential thermal analysis coupled with mass analysis of the volatile species. During thermal aging at 363 K, evolution of hydrogen, aminoborane and borazine is monitored, with the relative mass loss strongly depending on the pressure in the reaction chamber. Furthermore, the induction period required for hydrogen release at 363 K decreases with decreasing pressure.

Palumbo, Oriele; Paolone, Annalisa; Rispoli, Pasquale; Cantelli, Rosario; Autrey, Thomas

2010-03-15T23:59:59.000Z

216

New constraints on methane fluxes and rates of anaerobic methane oxidation in a Gulf of Mexico brine pool via in situ mass spectrometry  

E-Print Network (OSTI)

New constraints on methane fluxes and rates of anaerobic methane oxidation in a Gulf of Mexico Keywords: Methane flux Mass spectrometer Brine pool Methane oxidation Gulf of Mexico a b s t r a c t Deep report direct measurements of methane concentrations made in a Gulf of Mexico brine pool located

Girguis, Peter R.

217

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

218

High-Throughput Proteomics Using High Efficiency Multiple-Capillary Liquid Chromatography With On-Line High-Performance ESI FTICR Mass Spectrometry  

Science Conference Proceedings (OSTI)

We report on the design and application of a high-efficiency multiple-capillary liquid chromatography (LC) system for high-throughput proteome analysis. The multiple-capillary LC system was operated at the pressure of 10,000 psi using commercial LC pumps to deliver the mobile phase and newly developed passive feedback valves to switch the mobile phase flow and introduce samples. The multiple-capillary LC system was composed of several serially connected dual-capillary column devices. The dual-capillary column approach was designed to eliminate the time delay for regeneration (or equilibrium) of the capillary column after its use under the mobile phase gradient condition (i.e. one capillary column was used in separation and the other was washed using mobile phase A). The serially connected dual-capillary columns and ESI sources were operated independently, and could be used for either''backup'' operation or with other mass spectrometer(s). This high-efficiency multiple-capillary LC system uses switching valves for all operations and is highly amenable to automation. The separations efficiency of dual-capillary column device, optimal capillary dimensions (column length and packed particle size), suitable mobile phases for electrospray, and the capillary re-generation were investigated. A high magnetic field (11.5 tesla) Fourier transform ion cyclotron resonance (FTICR) mass spectrometer was coupled on-line with this high-efficiency multiple-capillary LC system through an electrospray ionization source. The capillary LC provided a peak capacity of {approx}600, and the 2-D capillary LC-FTICR provided a combined resolving power of > 6 x 10 7 polypeptide isotopic distributions. For yeast cellular tryptic digests, > 100,000 polypeptides were typically detected, and {approx}1,000 proteins can be characterized in a single run.

Shen, Yufeng (BATTELLE (PACIFIC NW LAB)); Tolic, Nikola (BATTELLE (PACIFIC NW LAB)); Zhao, Rui (ASSOC WESTERN UNIVERSITY); Pasa Tolic, Ljiljana (BATTELLE (PACIFIC NW LAB)); Li, Lingjun (Illinois Univ Of-Urbana/Champa); Berger, Scott J. (ASSOC WESTERN UNIVERSITY); Harkewicz, Richard (BATTELLE (PACIFIC NW LAB)); Anderson, Gordon A. (BATTELLE (PACIFIC NW LAB)); Belov, Mikhail E. (BATTELLE (PACIFIC NW LAB)); Smith, Richard D. (BATTELLE (PACIFIC NW LAB))

2000-12-01T23:59:59.000Z

219

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

Science Conference Proceedings (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

220

Chemical microsensors  

DOE Patents (OSTI)

An article of manufacture is provided including a substrate having an oxide surface layer and a selective thin film of a cyclodextrin derivative chemically bound upon said substrate, said film is adapted for the inclusion of a selected organic compound therewith. Such an article can be either a chemical sensor capable of detecting a resultant mass change from inclusion of the selected organic compound or a chemical separator capable of reversibly selectively separating a selected organic compound.

Li, DeQuan (Los Alamos, NM); Swanson, Basil I. (Los Alamos, NM)

1995-01-01T23:59:59.000Z

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.


221

3D Molecular Bioimaging Mass Spectrometry  

Science Conference Proceedings (OSTI)

... ion images as a function of increasing depth during dynamic SIMS sputtering of ... used which in turn allows for higher sputtering rates, faster analysis ...

2012-10-02T23:59:59.000Z

222

Improving gene annotation using peptide mass spectrometry  

E-Print Network (OSTI)

Tanner, Zhouxin Shen, Julio Ng, Liliana Florea, Roderic1,6 Zhouxin Shen, 2 Julio Ng, 1 Liliana Florea, 3 Roderic

2007-01-01T23:59:59.000Z

223

Improved Ambient Ionization Source for Mass Spectrometry ...  

Pacific Northwest National Laboratory Skip to Main Content U.S. Department of Energy. Search PNNL. PNNL Home; About; Research; Publications; Jobs; ...

224

CAMS Center for Accelerator Mass Spectrometry  

NLE Websites -- All DOE Office Websites (Extended Search)

research Lichen research Dinosaur bone research Biology Earth Science About CAMS Tour CAMS History of CAMS Meet the CAMS Staff CAMS Publications CAMS Home Seminars Download...

225

Investigation of the effect of intra-molecular interactions on the gas-phase conformation of peptides as probed by ion mobility-mass spectrometry, gas-phase hydrogen/deuterium exchange, and molecular mechanics  

E-Print Network (OSTI)

Ion mobility-mass spectrometry (IM-MS), gas-phase hydrogen/deuterium (H/D) exchange ion molecule reactions and molecular modeling provide complimentary information and are used here for the characterization of peptide ion structure, including fine structure detail (i.e., cation-? interactions, ?-turns, and charge solvation interactions). IM-MS experiments performed on tyrosine containing tripeptides show that the collision cross-sections of sodiated, potassiated and doubly sodiated species of gly-gly-tyr are smaller than that of the protonated species, while the cesiated and doubly cesiated species are larger. Conversely, all of the alkali-adducted species of try-gly-gly have collision cross-sections that are larger than that of the protonated species. The protonated and alkali metal ion adducted (Na+, K+ and Cs+) species of bradykinin and bradykinin fragments 1-5, 1-6, 1-7, 1-8, 2-7, 5-9 and 2-9 were also studied using IM-MS and the alkali metal ion adducts of these species were found to have cross-sections very close to those of the protonated species. Additionally, multiple peak features observed in the ATDs of protonated bradykinin fragments 1-5, 1-6 and 1-7 are conserved upon alkali metal ion adduction. It was observed from gas-phase H/D ion molecule reactions that alkali adducted species exchange slower and to a lesser extent than protonated species in the tyrosine- and arginine-containing peptides. Experimental and computational results are discussed in terms of peptide ion structure, specifically the intra-molecular interactions present how those interactions change upon alkali salt adduction, as well as with the sequence of the peptide. Additionally, IM-MS data suggests the presence of a compact conformation of bradykinin fragment 1-5 (RPPGF) when starting from organic solvent conditions. As water is added stepwise to methanolic solutions, a more extended conformation is populated. When the starting solution is composed of ?90% water, two distinct mobility profiles are observed as well as a shoulder, indicating the presence of three gas-phase conformations for RPPGF. Gas-phase H/D exchange of [M+H]+ ions prepared from aqueous solvents show a bi-exponential decay, whereas samples prepared from organic solvents show a single exponential decay. The effect of solvent on gas-phase peptide ion structure, i.e., solution-phase memory effects, is discussed and gas-phase structures are compared to know solution-phase structures.

Sawyer, Holly Ann

2004-12-01T23:59:59.000Z

226

JOURNAL OF MASS SPECTROMETRY J. Mass Spectrom. 2008; 43: 11611180  

E-Print Network (OSTI)

the rapid addition of energy to a condensed-phase sample (e.g. heat, photons, droplet or gas impact) results/ionization techniques in use with MS (Fig. 1). Introduced in the mid-1970s, commercially available in the 1980s. In this approach to surface sampling, heat is used to liberate the sample intact from the condensed phase

227

Activation Measurements for Thermal Neutrons, U.S. Measurements of 36Cl in Mineral Samples from Hiroshima and Nagasaki; and Measurement of 63 Ni in Copper Samples From Hiroshima by Accelerator Mass Spectrometry  

SciTech Connect

The present paper presents the {sup 36}Cl measurement effort in the US. A large number of {sup 36}Cl measurements have been made in both granite and concrete samples obtained from various locations and distances in Hiroshima and Nagasaki. These measurements employed accelerator mass spectrometry (AMS) to quantify the number of atoms of {sup 36}Cl per atom of total Cl in the sample. Results from these measurements are presented here and discussed in the context of the DS02 dosimetry reevaluation effort for Hiroshima and Nagasaki atomic-bomb survivors. The production of {sup 36}Cl by bomb neutrons in mineral samples from Hiroshima and Nagasaki was primarily via the reaction {sup 35}Cl(n,{gamma}){sup 36}Cl. This reaction has a substantial thermal neutron cross-section (43.6 b at 0.025 eV) and the product has a long half-life (301,000 y). hence, it is well suited for neutron-activation detection in Hiroshima and Nagasaki using AMS more than 50 years after the bombings. A less important reaction for bomb neutrons, {sup 39}K(n,{alpha}){sup 36}Cl, typically produces less than 10% of the {sup 36}Cl in mineral samples such as granite and concrete, which contain {approx} 2% potassium. In 1988, only a year after the publication of the DS86 final report (Roesch 1987), it was demonstrated experimentally that {sup 36}Cl measured using AMS should be able to detect the thermal neutron fluences at the large distances most relevant to the A-bomb survivor dosimetry. Subsequent measurements in mineral samples from both Hiroshima and Nagasaki validated the experimental findings. The potential utility of {sup 36}Cl as a thermal neutron detector in Hiroshima was first presented by Haberstock et al. who employed the Munich AMS facility to measure {sup 36}Cl/Cl ratios in a gravestone from near the hypocenter. That work subsequently resulted in an expanded {sup 36}Cl effort in Germany that paralleled the US work. More recently, there have also been {sup 36}Cl measurements made by a Japanese group. The impetus for the extensive {sup 36}Cl and other neutron activation measurements was the recognized need to validate the neutron component of the dose in Hiroshima. Although this was suggested at the time of the DS86 Final Report, where it was stated that the calculated neutron doses for survivors could possibly be wrong, the paucity of neutron validation measurements available at that time prevented adequate resolution of this matter. It was not until additional measurements and data evaluations were made that it became clear that more work was required to better understand the discrepancies observed for thermal neutrons in Hiroshima. This resulted in a large number of additional neutron activation measurements in Hiroshima and Nagasaki by scientists in the US, Japan, and Germany. The results presented here for {sup 36}Cl, together with measurements made by other scientists and for other isotopes, now provide a much improved measurement basis for the validation of neutrons in Hiroshima.

Tore Straume; Alfredo A. Marchetti; Stephen D. Egbert; James A. Roberts; Ping Men; Shoichiro Fujita; Kiyoshi Shizuma; Masaharu Hoshi; G. Rugel; W. Ruhm; G. Korschinek; J. E. McAninch; K. L. Carroll; T. Faestermann; K. Knie; R. E. Martinelli; A. Wallner; C. Wallner

2005-01-14T23:59:59.000Z

228

Center for Nanophase Materials Sciences (CNMS) - Chemical Functionalit...  

NLE Websites -- All DOE Office Websites (Extended Search)

using nitrogen. Raman spectroscopy Raman spectroscopy with multi-wavelength laser system (20 laser excitations, from UV Raman to NIR Raman) and online mass spectrometry for...

229

Resolving Emissions Dynamics via Mass Spectrometry: Time Resolved Measurements of Emission Transients by Mass Spectrometry  

DOE Green Energy (OSTI)

Transient emissions occur throughout normal engine operation and can significantly contribute to overall system emissions. Such transient emissions may originate from various sources including cold start, varying load and exhaust-gas recirculation (EGR) rates; all of which are dynamic processes in the majority of engine operation applications (1). Alternatively, there are systems which are inherently dynamic even at steady-state engine-operation conditions. Such systems include catalytic exhaust-emissions treatment devices with self-initiated and sustained oscillations (2) and NOX adsorber systems (3,4,5). High-speed diagnostics, capable of temporally resolving such emissions transients, are required to characterize the process, verify calculated system inputs, and optimize the system.

Partridge, William P.

2000-08-20T23:59:59.000Z

230

LOW PRESSURE CHEMICAL VAPOR DEPOSITION OF POLYSILICON  

E-Print Network (OSTI)

THEORY The mass transport processes in low pressure chemical vapor deposition (LPCVD) are similar to those occuring in catalytic reactors

Gieske, R.J.

2011-01-01T23:59:59.000Z

231

Increasing Confidence of LC-MS Identifications by Utilizing Ion Mobility Spectrometry  

SciTech Connect

Ion mobility spectrometry in conjunction with liquid chromatography separations and mass spectrometry offers a range of new possibilities for analyzing complex biological samples. To fully utilize the information obtained from these three measurement dimensions, informatics tools based on the accurate mass and time tag methodology were modified to incorporate ion mobility spectrometry drift times for peptides observed in human serum. A reference human serum database was created using 12,139 peptides, tracking the monoisotopic mass, liquid chromatography normalized elution time, and ion mobility spectrometry drift time(s) for each peptide. We demonstrate that the use of three dimensions for peak matching during the peptide identification process resulted in increased numbers of identifications and lower false discovery rates relative to the use of only the mass and normalized elution time dimensions.

Crowell, Kevin L.; Baker, Erin Shammel; Payne, Samuel H.; Ibrahim, Yehia M.; Monroe, Matthew E.; Slysz, Gordon W.; Lamarche, Brian L.; Petyuk, Vladislav A.; Piehowski, Paul D.; Danielson, William F.; Anderson, Gordon A.; Smith, Richard D.

2013-09-05T23:59:59.000Z

232

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

233

Measuring the Effect of Fuel Chemical Structure on Particulate and Gaseous Emissions using Isotope Tracing  

DOE Green Energy (OSTI)

Using accelerator mass spectrometry (AMS), a technique initially developed for radiocarbon dating and recently applied to internal combustion engines, carbon atoms within specific fuel molecules can be labeled and followed in particulate or gaseous emissions. In addition to examining the effect of fuel chemical structure on emissions, the specific source of carbon for PM can be identified if an isotope label exists in the appropriate fuel source. Existing work has focused on diesel engines, but the samples (soot collected on quartz filters or combustion gases captured in bombs or bags) are readily collected from large industrial combustors as well.

Buchholz, B A; Mueller, C J; Martin, G C; Upatnicks, A; Dibble, R W; Cheng, S

2003-09-11T23:59:59.000Z

234

Author manuscript, published in "8th World Congress of Chemical Engineering, Montréal: Canada (2009)" A SIMPLE GAS-LIQUID MASS TRANSFER JET SYSTEM,  

E-Print Network (OSTI)

Abstract: An original gas-liquid contacting system is proposed, consisting of a pump, an orifice, a vertical tube coaxial to the orifice and an impinging plate. The pump generates a downward vertical liquid jet through the orifice situated above the gas-liquid dispersion level. The two phase jet is directed towards an impinging plate near the bottom of the tank and dispersed in the volume of the liquid. Liquid is withdrawn below the impinging plate and recycled. This reactor may be used for gas-liquid reactions (ie hydrogenations) and also to mix liquids, to disperse particles, to oxygenate waste water etc…. Performances and design rules of this equipment are proposed. Then, the results are compared to performances of bubble columns, stirred tanks, and other academic and industrial jet systems. It is shown that, at a given energy dissipation, this system yields much higher mass transfer densities than a classical stirred tank provided with a Rushton turbine. Finally some suggestions about mass transfer mechanisms and efficiency of dissipated power are given.

Roger Botton; Dominique Cosserat; Souhila Poncin; Gabriel Wild

2009-01-01T23:59:59.000Z

235

Chemical and Structural Features of Plants That Contribute to Biomass Recalcitrance  

E-Print Network (OSTI)

of the Pyrolysis of Biomass. 1. Fundamentals. Energy Fuelsof the Pyrolysis of Biomass. 1. Fundamentals. Energy Fuelsand Pyrolysis Molecular Beam Mass Spectrometry. Biomass

DeMartini, Jaclyn Diana

2011-01-01T23:59:59.000Z

236

A support vector machine model for the prediction of proteotypic peptides for accurate mass and time proteomics  

Science Conference Proceedings (OSTI)

Motivation: The standard approach to identifying peptides based on accurate mass and elution time (AMT) compares profiles obtained from a high resolution mass spectrometer to a database of peptides previously identified from tandem mass spectrometry ...

Bobbie-Jo M. Webb-Robertson; William R. Cannon; Christopher S. Oehmen; Anuj R. Shah; Vidhya Gurumoorthi; Mary S. Lipton; Katrina M. Waters

2010-07-01T23:59:59.000Z

237

A support vector machine model for the prediction of proteotypic peptides for accurate mass and time proteomics  

Science Conference Proceedings (OSTI)

Motivation: The standard approach to identifying peptides based on accurate mass and elution time (AMT) compares profiles obtained from a high resolution mass spectrometer to a database of peptides previously identified from tandem mass spectrometry ...

Bobbie-Jo M. Webb-Robertson; William R. Cannon; Christopher S. Oehmen; Anuj R. Shah; Vidhya Gurumoorthi; Mary S. Lipton; Katrina M. Waters

2008-07-01T23:59:59.000Z

238

Subscriber access provided by Indiana University Analytical Chemistry is published by the American Chemical Society. 1155  

E-Print Network (OSTI)

in developing new ion mobility spectrometry (IMS) technologies that couple with mass spectrometry (MS) analyses Mobility Spectrometry Samuel I. Merenbloom, Rebecca S. Glaskin, Zachary B. Henson, and David E. Clemmer permission to reproduce figures and/or text from this article #12;High-Resolution Ion Cyclotron Mobility

Clemmer, David E.

239

Chemical leukoderma  

E-Print Network (OSTI)

the first report, to date, of chemical leukoderma that wasreview on biological, chemical and clinical aspects. Pigment4. Briganti S, et al. Chemical and instrumental approaches

O'Reilly, Kathryn E; Patel, Utpal; Chu, Julie; Patel, Rishi; Machler, Brian C

2011-01-01T23:59:59.000Z

240

The History of Nuclidic Masses and of their Evaluation  

E-Print Network (OSTI)

This paper is centered on some historical aspects of nuclear masses, and their relations to major discoveries. Besides nuclear reactions and decays, the heart of mass measurements lies in mass spectrometry, the early history of which will be reviewed first. I shall then give a short history of the mass unit which has not always been defined as one twelfth of the carbon-12 mass. When combining inertial masses from mass spectrometry with energy differences obtained in reactions and decays, the conversion factor between the two is essential. The history of the evaluation of the nuclear masses (actually atomic masses) is only slightly younger than that of the mass measurements themselves. In their modern form, mass evaluations can be traced back to 1955. Prior to 1955, several tables were established, the oldest one in 1935.

G. Audi

2006-02-08T23:59:59.000Z

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.


241

Molecular-Beam Mass-Spectrometric Analyses of Hydrocarbon Flames.  

E-Print Network (OSTI)

??Laminar flat flame combustion has been studied with molecular-beam mass-spectrometry (MBMS) for a fuel-rich cyclohexane (? = 2.003) flame, a fuel-lean toluene (? = 0.895),… (more)

Gon, Saugata

2008-01-01T23:59:59.000Z

242

Mass Spectrometry of Synthetic-Polymer Mixtures Workshop  

Science Conference Proceedings (OSTI)

... is held at constant total energy), changes in ... combining his continuum model theory with molecular ... than that found by nuclear magnetic resonance. ...

2013-09-30T23:59:59.000Z

243

OBT Measurement of Vegetation by Mass Spectrometry and Radiometry  

Science Conference Proceedings (OSTI)

Environmental and Organically Bound Tritium / Proceedings of the Ninth International Conference on Tritium Science and Technology (Part 2)

T. Tamari; H. Kakiuchi; N. Momoshima; N. Baglan; S. Sugihara; T. Uda

244

Applications of Ionic Clusters in High Resolution Mass Spectrometry  

E-Print Network (OSTI)

of the ions by blackbody radiation or collisions withcathode heated due to blackbody radiation from the cell andby absorption of blackbody radiation, the precursor ions

Leib, Ryan David

2010-01-01T23:59:59.000Z

245

Quantification of neptunium by isotope dilution mass spectrometry  

SciTech Connect

A surface ionization-diffusion-type ionization source that uses a rhenium filament overplated with platinum has been developed and optimized for 0.1-ng neptunium samples. This source is capable of measuring the neptunium content of nuclear-test-debris samples to 0.15% precision at the 95% confidence level. 14 refs., 3 figs., 3 tabs.

Efurd, D.W.; Drake, J.; Roensch, F.R.; Cappis, J.H.; Perrin, R.E.

1986-05-01T23:59:59.000Z

246

High-Sensitivity Ion Mobility Spectrometry/Mass ...  

... Bowers, M. T.; Kemper, P. R.; von Helden, G.; van Koppen, P. A. M. Science 1993, 260, 1446 ... (Ł), which results in large ion ... and R d is the ...

247

Mass spectrometry of nuclear materials; Attention to detail  

SciTech Connect

Measurements of the {sup 235}U/{sup 238}U ratio in product-quality material have improved from uncertainties of 0.1 percent (rel) to 0.2 percent since the Manhattan Project. The hardware and procedural changes responsible for these measurement improvements are traced and discussed.

Shields, W.R

1989-11-01T23:59:59.000Z

248

Secondary Ion Mass Spectrometry of Vapor-Liquid-Solid Grown,  

E-Print Network (OSTI)

photovoltaic cells,1-5 field-effect transistors,6,7 light-emitting diodes,8 photodetectors,9 and molecular sen

Heaton, Thomas H.

249

Advances in computational mass spectrometry : phosphoprotoemics and proteogenomics  

E-Print Network (OSTI)

and phosphorylation mediated NF-KB activiation. Four histoneto be activated, or relay the signal. In NF-KB signaling, atranscription factor (NF-KB) is held inactive outside the

Payne, Samuel Harris

2008-01-01T23:59:59.000Z

250

Hadamard Transform Time-of-Flight Mass Spectrometry  

E-Print Network (OSTI)

of the ions. This multiplexing scheme in- creases the ion usage to 50% for a single detector instrument consists of a combination of magnetic and electric resolving stages. This is probably the oldest type

Zare, Richard N.

251

2-4 High-Performance Mass Spectrometry Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

through soil and into groundwater. The mechanism for this reduction in contaminant mobility is the transfer of an electron to the heavy metal through cell surface proteins...

252

New Chemical Aerosol Characterization Methods- Examples Using Agricultural and Urban Airborne Particulate Matter  

E-Print Network (OSTI)

This study explored different chemical characterization methods of agricultural and urban airborne particulate matter. Three different field campaigns are discussed. For the agricultural aerosols, measurement of the chemical composition of size-resolved agricultural aerosols collected from a ground site at the nominally downwind and upwind edge of a feedlot in West Texas were reported. High volume cascade impactor samplers were used for the collection of the particles, and two major analytical methods were applied to characterize different components of the aerosols, ion chromatography (IC ) was used to measure ionic composition with the main targets being ammonium (NH4 ), nitrate (NO3 -), and sulfate (SO4 2-), direct thermal desorption gas chromatography-mass spectrometry/flame ionization detection (GC-MS/FID) methodology was used to identify and quantify organic compounds in the aerosol particles. For the urban aerosols, I report the measurement of mass, and the chemical composition of size-resolved aerosols collected from two different locations in Houston, analyzed by the thermal desorption GC-MS/FID method. The investigation of single particle composition using RM is reported as well: RM and chemical mapping techniques have been applied for the qualitative analysis of components in the samples of air particulate matter collected in downtown Houston.

Zhou, Lijun

2010-08-01T23:59:59.000Z

253

NIST - Physical and Chemical Properties Division - Technical ...  

Science Conference Proceedings (OSTI)

... 1. The NIST WebBook - NIST Chemical Reference Data for ... The NIST Mass Spectral Database: Extending the ... of fluids and fluid mixtures, including ...

254

Stable Isotope, Site-Specific Mass Tagging For Protein Identification  

NLE Websites -- All DOE Office Websites (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

255

Negative mass  

E-Print Network (OSTI)

Some physical aspects of negative mass are examined. Several unusual properties, such as the ability of negative mass to penetrate any armor, are analyzed. Other surprising effects include the bizarre system of negative mass chasing positive pass, naked singularities and the violation of cosmic censorship, wormholes, and quantum mechanical results as well. In addition, a brief look into the implications for strings is given.

Richard T Hammond

2013-08-06T23:59:59.000Z

256

doi:10.1155/2011/839682 Review Article Haptenation: Chemical Reactivity and Protein Binding  

E-Print Network (OSTI)

Copyright © 2011 Itai Chipinda et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Low molecular weight chemical (LMW) allergens are commonly referred to as haptens. Haptens must complex with proteins to be recognized by the immune system. The majority of occupationally related haptens are reactive, electrophilic chemicals, or are metabolized to reactive metabolites that form covalent bonds with nucleophilic centers on proteins. Nonelectrophilic protein binding may occur through disulfide exchange, coordinate covalent binding onto metal ions on metalloproteins or of metal allergens, themselves, to the major histocompatibility complex. Recent chemical reactivity kinetic studies suggest that the rate of protein binding is a major determinant of allergenic potency; however, electrophilic strength does not seem to predict the ability of a hapten to skew the response between Th1 and Th2. Modern proteomic mass spectrometry methods that allow detailed delineation of potential differences in protein binding sites may be valuable in predicting if a chemical will stimulate an immediate or delayed hypersensitivity. Chemical aspects related to both reactivity and protein-specific binding are discussed. 1.

Itai Chipinda; Justin M. Hettick; Paul D. Siegel

2011-01-01T23:59:59.000Z

257

Chemical Science  

NLE Websites -- All DOE Office Websites (Extended Search)

reactor concept for deep space exploration Research directions Weapons chemistry and nuclear performance Radiological, nuclear, and chemical signatures Energy production,...

258

Using chemical tracers in hillslope soils to estimate the importance of chemical denudation under  

E-Print Network (OSTI)

Using chemical tracers in hillslope soils to estimate the importance of chemical denudation under mass. The model includes both sediment transport and chemical denudation. A simplified two-phase model is developed; the two phases are a chemically immobile phase, which has far lower solubility than the bulk soil

259

Safeguards Verification Measurements using Laser Ablation, Absorbance Ratio Spectrometry in Gaseous Centrifuge Enrichment Plants  

Science Conference Proceedings (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); Phillips, Jon R.

2012-07-01T23:59:59.000Z

260

Fisher ratio method applied to third-order separation data to identify significant chemical components of metabolite extracts  

Science Conference Proceedings (OSTI)

This report is about applying a Fisher ratio method to entire four dimensional (4D) data sets from third-order instrumentation data. The Fisher ratio method uses a novel indexing scheme to discover the unknown chemical differences among known classes of complex samples. This is the first report of a Fisher ratio analysis procedure applied to entire 4D data sets of third-order separation data, which, in this case, is comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry analyses of metabolite extracts using all of the collected mass channels. Current analysis methods for third-order separation data use only userdefined subsets of the 4D data set.

Pierce, Karisa M.; Hoggard, Jamin C.; Hope, Janiece L.; Rainey, Petrie M.; Hoofnagle, Andrew N.; Jack, Rhona M.; Wright, Bob W.; Synovec, Robert E.

2006-07-15T23:59:59.000Z

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.


261

Mass Measurements  

Science Conference Proceedings (OSTI)

... NIST maintains the national standard for mass in the form of the prototype kilogram (K20) and provides services to support the parts of the national ...

2013-06-28T23:59:59.000Z

262

fehlende Masse  

NLE Websites -- All DOE Office Websites (Extended Search)

beim radioaktiven Zerfall mit der fehlenden Masse?" Zur Erinnerung: wenn Uran in Thorium und ein alpha Teilchen zerfllt, dann gehen 0.0046 u (Masseneinheiten) der...

263

Chemical sensors  

DOE Patents (OSTI)

Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising (a) a mechanochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, operatively coupled to (b) a transducer capable of directly converting said expansion or contraction to a measurable electrical response.

Lowell, Jr., James R. (Bend, OR); Edlund, David J. (Bend, OR); Friesen, Dwayne T. (Bend, OR); Rayfield, George W. (Bend, OR)

1991-01-01T23:59:59.000Z

264

Chemical preconcentrator  

DOE Patents (OSTI)

A chemical preconcentrator is disclosed with applications to chemical sensing and analysis. The preconcentrator can be formed by depositing a resistive heating element (e.g. platinum) over a membrane (e.g. silicon nitride) suspended above a substrate. A coating of a sorptive material (e.g. a microporous hydrophobic sol-gel coating or a polymer coating) is formed on the suspended membrane proximate to the heating element to selective sorb one or more chemical species of interest over a time period, thereby concentrating the chemical species in the sorptive material. Upon heating the sorptive material with the resistive heating element, the sorbed chemical species are released for detection and analysis in a relatively high concentration and over a relatively short time period. The sorptive material can be made to selectively sorb particular chemical species of interest while not substantially sorbing other chemical species not of interest. The present invention has applications for use in forming high-sensitivity, rapid-response miniaturized chemical analysis systems (e.g. a "chem lab on a chip").

Manginell, Ronald P. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM)

2001-01-01T23:59:59.000Z

265

RAPID COMMUNICATIONS IN MASS SPECTROMETRY Rapid Commun. Mass Spectrom. 2005; 19: 34423450  

E-Print Network (OSTI)

and oxygen isotope ratios of bottled waters of the world Gabriel J. Bowen1 *, David A. Winter2 , Howard J Biology Department, University of Utah, Salt Lake City, UT 84112, USA 2 Department of Geology, University of Calfornia, Davis, CA 95616, USA 3 Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, USA

Ehleringer, Jim

266

CHEMICAL ENGINEERING AND MANUFACTURING CHEMICAL ENGINEERING  

E-Print Network (OSTI)

CHEMICAL ENGINEERING AND MANUFACTURING CHEMICAL ENGINEERING Objective Chemical Engineers of chemicals. This lesson introduces students to one component of chemical engineering: food processing, and a chemical engineer 2. How chemical engineers are involved in food production 3. That chemical engineers need

Provancher, William

267

Field Asymmetric Ion Mobility Spectrometry (FAIMS ...  

Summary. Field asymmetric Ion mobility spectrometry (FAIMS), wherein ions are separated and/or characterized by differences in their mobility in high ...

268

In Situ Chemical Characterization of Aged Biomass-Burning Aerosols Impacting Cold Wave Clouds  

Science Conference Proceedings (OSTI)

During the Ice in Clouds Experiment–Layer Clouds (ICE-L), aged biomass-burning particles were identified within two orographic wave cloud regions over Wyoming using single-particle mass spectrometry and electron microscopy. Using a suite of ...

Kerri A. Pratt; Andrew J. Heymsfield; Cynthia H. Twohy; Shane M. Murphy; Paul J. DeMott; James G. Hudson; R. Subramanian; Zhien Wang; John H. Seinfeld; Kimberly A. Prather

2010-08-01T23:59:59.000Z

269

Chemical Activation  

NLE Websites -- All DOE Office Websites (Extended Search)

Chemical Activation of Single-walled Carbon Nanotubes for Hydrogen Adsorption Milton R. Smith, Jr., 1 Edward W. Bittner, 1 Wei Shi, 1, 2 J. Karl Johnson, 1, 2 and Bradley C....

270

Chemical sensors  

DOE Patents (OSTI)

Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising a mechanicochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, either operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical or optical response, or adhered to a second inert polymeric strip, or doped with a conductive material. 12 figs.

Lowell, J.R. Jr.; Edlund, D.J.; Friesen, D.T.; Rayfield, G.W.

1992-06-09T23:59:59.000Z

271

Chemical sensors  

DOE Patents (OSTI)

Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising a mechanicochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, either operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical or optical response, or adhered to a second inert polymeric strip, or doped with a conductive material.

Lowell, Jr., James R. (Bend, OR); Edlund, David J. (Bend, OR); Friesen, Dwayne T. (Bend, OR); Rayfield, George W. (Eugene, OR)

1992-01-01T23:59:59.000Z

272

Atmospheric-Pressure Chemical Vapor Deposition of Iron Pyrite Thin Films  

Science Conference Proceedings (OSTI)

Iron pyrite (cubic FeS{sub 2}) is a promising candidate absorber material for earth-abundant thin-film solar cells. In this report, single-phase, large-grain, and uniform polycrystalline pyrite thin films are fabricated on glass and molybdenum-coated glass substrates by atmospheric-pressure chemical vapor deposition (AP-CVD) using the reaction of iron(III) acetylacetonate and tert-butyl disulfide in argon at 300 C, followed by sulfur annealing at 500--550 C to convert marcasite impurities to pyrite. The pyrite-marcasite phase composition depends strongly on the concentration of sodium in the growth substrate and the sulfur partial pressure during annealing. Phase and elemental composition of the films are characterized by X-ray diffraction, Raman spectroscopy, Auger electron spectroscopy, secondary ion mass spectrometry, Rutherford backscattering spectrometry, and X-ray photoelectron spectroscopy. The in-plane electrical properties are surprisingly insensitive to phase and elemental impurities, with all films showing p-type, thermally activated transport with a small activation energy ({approx}30 meV), a room- temperature resistivity of {approx}1 {Omega} cm, and low mobility. These ubiquitous electrical properties may result from robust surface effects. These CVD pyrite thin films are well suited to fundamental electrical studies and the fabrication of pyrite photovoltaic device stacks.

Berry, Nicholas; Cheng, Ming; Perkins, Craig L.; Limpinsel, Moritz; Hemminger, John C.; Law, Matt (NREL); (UCI)

2012-10-23T23:59:59.000Z

273

Solvent Extraction of Chemical Attribution Signature Compounds from Painted Wall Board: Final Report  

DOE Green Energy (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

274

Mass Finishing  

Science Conference Proceedings (OSTI)

Table 8 Operating conditions for mass finishing...Brass screw-machine parts Aluminum oxide or granite 6.4-19 0.25-0.75 [MathExpression] -6 Light matte or bright Light cutting (a) Brass stampings or screws (b) Limestone 3.2-13 0.13-0.50 2-6 Bright (a) Submerged tumbling is used for fragile and precision parts. (b) Screw-machine parts...

275

Compact hydrogen/helium isotope mass spectrometer  

DOE Patents (OSTI)

The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

Funsten, Herbert O. (Los Alamos, NM); McComas, David J. (Los Alamos, NM); Scime, Earl E. (Morgantown, WV)

1996-01-01T23:59:59.000Z

276

Chemical Evolution  

E-Print Network (OSTI)

In this series of lectures we first describe the basic ingredients of galactic chemical evolution and discuss both analytical and numerical models. Then we compare model results for the Milky Way, Dwarf Irregulars, Quasars and the Intra-Cluster- Medium with abundances derived from emission lines. These comparisons allow us to put strong constraints on the stellar nucleosynthesis and the mechanisms of galaxy formation.

Francesca Matteucci

2007-04-05T23:59:59.000Z

277

The mass distribution of quark matter  

E-Print Network (OSTI)

We analyze lattice QCD results on the equation of state in terms of infinitely many non-interacting massive ideal gas components. We find that the entire pressure-temperature curve can be described by a temperature independent mass distribution at vanishing chemical potential. We collect strong indications for a mass gap in this distribution, conjectured to be related confinement.

Biro, T S; Van, P; Zimányi, J

2006-01-01T23:59:59.000Z

278

Fundamental Chemical Metrology  

Science Conference Proceedings (OSTI)

... 3) atomic and x-ray fluorescence spectrometry, (4) gas metrology, (5 ... that control or affect the separation process in liquid chromatography stationary ...

2012-10-22T23:59:59.000Z

279

On the Aerosol Particle Size Distribution Spectrum in Alaskan Air Mass Systems: Arctic Haze and Non-Haze Episodes  

Science Conference Proceedings (OSTI)

Aerosols in central Alaskan winter air mass system were classified according to size by diffusive separation and light-scattering spectrometry. Particles entering central Alaska from the Pacific Marine environment had number concentrations ...

Glenn E. Shaw

1983-05-01T23:59:59.000Z

280

About Chemical Hazards  

NLE Websites -- All DOE Office Websites (Extended Search)

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...

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

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

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

2013-07-01T23:59:59.000Z

282

Mass Transport within Soils  

Science Conference Proceedings (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

283

Plasma Mass Filters For Nuclear Waste Reprocessing  

SciTech Connect

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

284

Higher-Order Mass Defect Analysis for Mass Spectra of Complex Organic Mixtures  

Science Conference Proceedings (OSTI)

Higher-order mass defect analysis is introduced as a unique formula assignment and visualization method for the analysis of complex mass spectra. This approach is an extension of the concepts of Kendrick mass transformation widely used for identification of homologous compounds differing only by a number of base units (e.g., CH2, H2, O, CH2O, etc.) in complex mixtures. We present an iterative renormalization routine for defining higher order homologous series and multidimensional clustering of mass spectral features. This approach greatly simplifies visualization of complex mass spectra and increases the number of chemical formulae that can be confidently assigned for given mass accuracy. The potential for using higher-order mass defects for data reduction and visualization is shown. Higher-order mass defect analysis is described and demonstrated through third-order analysis of a de-isotoped high-resolution mass spectrum of crude oil containing nearly 13,000 peaks.

Roach, Patrick J.; Laskin, Julia; Laskin, Alexander

2011-06-15T23:59:59.000Z

285

Chemical Science  

NLE Websites -- All DOE Office Websites (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

286

Mass and Lifetime Measurements in Storage Rings  

Science Conference Proceedings (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

287

Excursions in Chemical Dynamics  

E-Print Network (OSTI)

2009). [118] F. A. Cotton, Chemical Applications of GroupExcursions in Chemical Dynamics by Shervin Fatehi AFall 2010 Excursions in Chemical Dynamics Copyright 2010 by

Fatehi, Shervin

2010-01-01T23:59:59.000Z

288

Chemical vapor deposition sciences  

SciTech Connect

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.

1992-12-31T23:59:59.000Z

289

Production and Utilization of CO3- Produced by a Corona Discharge in Air for Atmospheric Pressure Chemical Ionization  

SciTech Connect

Atmospheric pressure chemical ionization is a multistep ionization process used in mass spectrometry and ion mobility spectrometry. The formation of product ions depends upon interactions with the analyte and the reactant ion species formed in the ionization source. The predominant reactant ion observed in a point-to-plane corona discharge in air occurs at m/z 60. There have been multiple references in the literature to the identity of this ion with some disagreement. It was postulated to be either CO3- or N2O2-. The identity of this ion is important as it is a key to the ionization of analytes. It was determined here to be CO3- through the use of 18O labeled oxygen. Further confirmation was provided through MS/MS studies. The ionization of nitroglycerine (NG) with CO3- produced the adduct NG•CO3-. This was compared to ionization with NO3- and Cl- reactant ions that also formed adducts with NG. The fragmentation patterns of these three adducts provides insight into the charge distribution and indicates that CO3- has a relatively high electron affinity similar to that of nitrate.

Ewing, Robert G.; Waltman, Melanie J.

2010-12-14T23:59:59.000Z

290

Searching for the Solar System's Chemical Recipe  

NLE Websites -- All DOE Office Websites (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.

291

High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors  

Science Conference Proceedings (OSTI)

We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m/{Delta}m > 2500. The system design is superior to conventional batch and flow reactors with accompanying product detection by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0-5000 amu in the current configuration). As a demonstration of the system performance we present data from ammonia oxidation on a Pt thin film showing resolved spectra of OH and NH{sub 3}.

Andersen, T.; Jensen, R.; Christensen, M. K.; Chorkendorff, I. [Department of Physics, Danish National Research Foundation's Center for Individual Nanoparticle Functionality (CINF), Technical University of Denmark, Building 312, DK-2800 Kgs. Lyngby (Denmark); Pedersen, T.; Hansen, O. [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech Building 345 East, DK-2800 Kgs. Lyngby (Denmark)

2012-07-15T23:59:59.000Z

292

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

293

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

294

Ultrasensitive Identification of Localization Variants of Modified Peptides Using Ion Mobility Spectrometry  

Science Conference Proceedings (OSTI)

Localization of the modification sites on peptides is challenging, particularly when multiple modifications or mixtures of localization isomers (variants) are involved. Such variants commonly coelute in liquid chromatography and may be undistinguishable in tandem mass spectrometry (MS/MS) for lack of unique fragments. Here, we have resolved the variants of singly and doubly phosphorylated peptides employing drift tube ion mobility spectrometry (IMS) coupled to time-of-flight mass spectrometry. Even with a moderate IMS resolving power of ~80, substantial separation was achieved for both 2+ and 3+ ions normally generated by electrospray ionization, including for the variant indistinguishable by MS/MS. Variants often exhibit a distribution of 3-D conformers, which can be adjusted for optimum IMS separation by prior field heating of ions in a funnel trap. The peak assignments were confirmed using MS/MS after IMS separation, but known species could be identified using just the ion mobility "tag". Avoiding the MS/MS step lowers the detection limit of localization variants to electron transfer dissociation in an Orbitrap MS.

Ibrahim, Yehia M.; Shvartsburg, Alexandre A.; Smith, Richard D.; Belov, Mikhail E.

2011-05-28T23:59:59.000Z

295

Overtone Mobility Spectrometry: Part 1. Experimental Observations  

E-Print Network (OSTI)

introduce a new approach for isolating ions having specific mobilities (or collision cross sections). IonsARTICLES Overtone Mobility Spectrometry: Part 1. Experimental Observations Ruwan T. Kurulugama, Indiana University, Bloomington, Indiana, USA A new method that allows a linear drift tube to be operated

Clemmer, David E.

296

Optimization of performance characteristics in a class of irreversible chemical pumps  

Science Conference Proceedings (OSTI)

A new irreversible cyclic model of a class of two-source chemical pumps, which are affected by not only finite-rate mass transfer and mass leak but also the internal dissipation resulting from friction, eddy currents and other irreversible effects inside ... Keywords: Chemical pump, Irreversibility, Mass transfer, Optimal analysis, Performance characteristic

Guoxing Lin; Jincan Chen; Ekkes BrüCk; Ben Hua

2006-04-01T23:59:59.000Z

297

Chemical Accelerators The phrase "chemical accelerators"  

E-Print Network (OSTI)

by one of us for devices that produce beams of chemically interesting species at relative kinetic energies of a few electron volts. Most studies of chemical kinetics made by traditional thermochemical. It is obvious that while some methods of theoretical chemical kinetics (for instance, "absolute" rate theory

Zare, Richard N.

298

Argonne Chemical Sciences & Engineering - Fundamental Interactions -  

NLE Websites -- All DOE Office Websites (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

299

Design and development of an ultrafine particle reflection-time-of-flight mass spectrometer  

E-Print Network (OSTI)

The primary motivation for the research is to study the effect of small particles on global climate. The study can also help to understand the dynamics involved with gas to particle conversion, which is being debated to be a rich source for atmospheric aerosol. However, the most important use would be to study health effects, since small particles easily diffuse into the lungs, with seemingly little physiological filtration mechanism. The research work involves the design, development and characterization of a single-ultrafine-particle mass spectrometer. The instrument aerodynamically size selects fine and ultrafine aerosol particles (size range 20 nm-1 []m), with a constant Stokes number, and focuses them into a vacuum chamber. This is achieved by changing the upstream pressure of the inlet, which changes aerodynamic drag experienced by the particle. After its entry into the chamber, the particle is ablated by a high power excimer laser, which produces ions from the original molecular constituents. Reflectron time-of-flight mass spectrometry is utilized to analyze the ions, and thus the chemical composition of the particle that was hit. The present work is aimed to overcome the shortcomings of previous instruments, while allowing for increased portability. The instrument is designed, fabricated and experimentally characterized. The first phase involves analysis of the particle beam generated by the inlet. An atomizer generates aerosols from a solution of 5% oleic acid and ethanol. The polydisperse aerosol is passed through a differential mobility analyzer to make a monodisperse mixture, which is transmitted through the inlet. The monodisperse particle beam is intercepted by glass slides, and the spot sizes are indicative of the beam shape and width at the slide positions. A theoretical analysis of the fluid flow field and particle trajectory is developed to correlate with the experimental results. The second phase involves calibration of the mass spectra, and measuring some particulate composition from the laboratory room air.

Das, Rishiraj

2002-01-01T23:59:59.000Z

300

Evolution of organic aerosol mass spectra upon heating: implications for OA phase and partitioning behavior  

Science Conference Proceedings (OSTI)

Vacuum Ultraviolet (VUV) photoionization mass spectrometry has been used to measure the evolution of chemical composition for two distinct organic aerosol types as they are passed through a thermodenuder at different temperatures. The two organic aerosol types considered are primary lubricating oil (LO) aerosol and secondary aerosol from the alpha-pinene + O3 reaction (alphaP). The evolution of the VUV mass spectra for the two aerosol types with temperature are observed to differ dramatically. For LO particles, the spectra exhibit distinct changes with temperature in which the lower m/z peaks, corresponding to compounds with higher vapor pressures, disappear more rapidly than the high m/z peaks. In contrast, the alphaP aerosol spectrum is essentially unchanged by temperature even though the particles experience significant mass loss due to evaporation. The variations in the LO spectra are found to be quantitatively in agreement with expectations from absorptive partitioning theory whereas the alphaP spectra suggest that the evaporation of alphaP derived aerosol appears to not be governed by partitioning theory. We postulate that this difference arises from the alphaP particles existing as in a glassy state instead of having the expected liquid-like behavior. To reconcile these observations with decades of aerosol growth measurements, which indicate that OA formation is described by equilibrium partitioning, we present a conceptual model wherein the secondary OA is formed and then rapidly converted from an absorbing form to a non-absorbing form. The results suggest that although OA growth may be describable by equilibrium partitioning theory, the properties of organic aerosol once formed may differ significantly from the properties determined in the equilibrium framework.

UC Davis; Cappa, Christopher D.; Wilson, Kevin R.

2010-10-28T23:59:59.000Z

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

Microfluidic chemical reaction circuits  

DOE Patents (OSTI)

New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

Lee, Chung-cheng (Irvine, CA); Sui, Guodong (Los Angeles, CA); Elizarov, Arkadij (Valley Village, CA); Kolb, Hartmuth C. (Playa del Rey, CA); Huang, Jiang (San Jose, CA); Heath, James R. (South Pasadena, CA); Phelps, Michael E. (Los Angeles, CA); Quake, Stephen R. (Stanford, CA); Tseng, Hsian-rong (Los Angeles, CA); Wyatt, Paul (Tipperary, IE); Daridon, Antoine (Mont-Sur-Rolle, CH)

2012-06-26T23:59:59.000Z

302

Laser induced chemical reactions  

E-Print Network (OSTI)

of Basic Energy Sciences, Chemical Sciences Division of theINFRARED LASER ENHANCEMENT OF CHEMICAL REACTIONS A. B. C. D.Laser Inhibition of Chemical Reaction Effect of Isotopic

Orel, Ann E.

2010-01-01T23:59:59.000Z

303

January 28, 2011 Kinetic Isotope Effects Predicted Correctly for a Mass Ratio of 36  

E-Print Network (OSTI)

January 28, 2011 Kinetic Isotope Effects Predicted Correctly for a Mass, and it has chemical properties very similar to a hydrogen atom, but very large), and the dynamics was thermally averaged to yield temperature-dependent chemical reaction rate

Truhlar, Donald G

304

Exhibitor: MURLIN CHEMICAL INC.  

Science Conference Proceedings (OSTI)

Murlin Chemical, Inc. manufactures Bone Ash at its plant located in West Conshohocken, Pennsylvania, USA. Established in 1978, Murlin Chemical supplies ...

305

Advances in field-portable mass spectrometers for on-site analytics  

Science Conference Proceedings (OSTI)

Learn how the combination of ambient ionization with portable mass spectroscopy can speed chemical analysis by streamlining sample preparation and throughput requirements. Advances in field-portable mass spectrometers for on-site analytics inform M

306

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

307

Chemical Safety Program  

NLE Websites -- All DOE Office Websites (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)

308

Chemical Product and Process Volume 2, Issue 1 2007 Article 10  

E-Print Network (OSTI)

chemical entities (NCEs) is a kinetic model of the reaction system. Once obtained, this allows the chemical for the kinetic terms Ri will be unknown. It is therefore difficult, especially when each chemical species may, the dynamics of well- mixed chemical systems typically obey the law of mass action kinetics and hence

Newcastle upon Tyne, University of

309

Formaldehyde and Other Volatile Organic Chemical Emissions in Four FEMA  

NLE Websites -- All DOE Office Websites (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

310

Mass spectrometric approaches for chemical characterisation of atmospheric aerosols: critical  

E-Print Network (OSTI)

). He received his M.Sc. degree (physics) in 1991 from the Leningrad Polytechnical Institute, Russia received her M.Sc. degree in physics from the Leningrad Polytechnical Institute (1990) and her Ph.D. degree Professor at the University of California, Irvine. He received his M.Sc. degree in biochemistry from

Nizkorodov, Sergey

311

Pushing the Frontier of High-Definition Ion Mobility Spectrometry Using FAIMS  

Science Conference Proceedings (OSTI)

Differential ion mobility spectrometry (FAIMS) separates ions in gases based on the difference between their mobilities in strong and weak electric fields, captured directly employing a periodic waveform with dissimilar profiles in opposite polarities. As that difference is not tightly correlated with the ion size or mass, FAIMS separations are generally quite orthogonal to both conventional IMS (based on the absolute ion mobility that reflects the physical ion size) and mass spectrometry (based on mass). Until a few years ago, that advantage was largely offset by poor FAIMS resolving power (?10–20), an order of magnitude below that achieved with conventional (drift-tube) IMS. This article summarizes the major recent technical developments that have raised FAIMS resolving power up to ?500. These include use of higher and more stable voltages provided by new waveform generators, novel buffer gas compositions comprising high helium or hydrogen fractions, and extended filtering times up to ?1 s. These advances have enabled previously unthinkable analyses such as broad baseline separations of peptide sequence inversions, localization variants (post-translationally modified peptides with differing PTM attachment sites) even for the larger “middle-down” peptides and smallest PTMs, and lipid regioisomers.

Shvartsburg, Alexandre A.; Anderson, Gordon A.; Smith, Richard D.

2013-05-03T23:59:59.000Z

312

Mercury's Protoplanetary Mass  

E-Print Network (OSTI)

Major element fractionation among chondrites has been discussed for decades as ratios relative to Si or Mg. Recently, by expressing ratios relative to Fe, I discovered a new relationship admitting the possibility that ordinary chondrite meteorites are derived from two components, a relatively oxidized and undifferentiated, primitive component and a somewhat differentiated, planetary component, with oxidation state like the highly reduced enstatite chondrites, which I suggested was identical to Mercury's complement of lost elements. Here, on the basis of that relationship, I derive expressions, as a function of the mass of planet Mercury and the mass of its core, to estimate the mass of Mercury's lost elements, the mass of Mercury's alloy and rock protoplanetary core, and the mass of Mercury's gaseous protoplanet. Although Mercury's mass is well known, its core mass is not, being widely believed to be in the range of 70-80 percent of the planet mass. For a core mass of 75 percent, the mass of Mercury's lost elements is about 1.32 times the mass of Mercury, the mass of the alloy and rock protoplanetary core is about 2.32 times the mass of Mercury, and the mass of the gaseous protoplanet of Mercury is about 700 times the mass of Mercury. Circumstantial evidence is presented in support of the supposition that Mercury's lost elements is identical to the planetary component of ordinary chondrite formation.

J. Marvin Herndon

2004-10-01T23:59:59.000Z

313

Chapter 13. Chemical Kinetics  

E-Print Network (OSTI)

of chemical reactions. · Only gases, for which the kinetic theory of Chapter 4 is applicable, are consideredChapter 13. Chemical Kinetics #12;· Why do some chemical reactions proceed with lighting speed when the way in which molecules combine to form products? · All of these questions involve chemical kinetics

Ihee, Hyotcherl

314

and Chemical Engineering  

E-Print Network (OSTI)

Biological and Chemical Engineering Building #12;2 Biological and Chemical Engineering Building sta is constructing a new building that will house the Department of Chemical Engineering and the Department and Chemical Engineering Building will provide critically needed space for innovators in multiple disciplines

Prinz, Friedrich B.

315

Chemical Sciences Division Homepage  

Science Conference Proceedings (OSTI)

... Development of Measurements and Standards for Biofuels; Chemical Metrology in Support of the US Hydrogen Infrastructure; ...

2013-06-07T23:59:59.000Z

316

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.

317

About Chemical Hazards  

NLE Websites -- All DOE Office Websites (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.

318

Selection and generation of waveforms for differential mobility spectrometry  

Science Conference Proceedings (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

319

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.

320

Boson stars: Chemical potential and quark condensates  

E-Print Network (OSTI)

We study the properties of a star made of self-gravitating bosons gas in a mean-field approximation. A generalized set of Tolman-Oppenheimer-Volkov(TOV) equations is derived to incorporate the effect of chemical-potential in the general relativistic frame work. The metric-dependence of the chemical-potential gives a new class of solutions for the boson stars. It is demonstrated that the maximum mass and radius of the star change in a significant way when the effect of finite chemical-potential is considered. We also discuss the case of a boson star made of quark-condensates. It is found that when the self-interaction between the condensates is small as compared to their mass, the typical density is too high to form a diquark-boson star. Our results indicate that the star of quark-condensate may be formed in a low-density and high-pressure regime.

Jitesh R. Bhatt; V. Sreekanth

2009-10-12T23:59:59.000Z

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

Growth of homo-epitaxial silicon at low temperatures using hot wire chemical vapor deposition  

DOE Green Energy (OSTI)

The authors report on the first known growth of high-quality epitaxial Si via the hot wire chemical vapor deposition (HWCVD) method. This method yields device-quality epitaxial Si at the comparatively low temperatures of 195 to 450 C, and relatively high growth rates of 3 to 20 {angstrom}/sec. Layers up to 4,500-{angstrom} thick have been grown. These epitaxial layers have been characterized by transmission electron microscopy (TEM), indicating large regions of nearly perfect atomic registration. Electron channeling patterns (ECPs) generated on a scanning electron microscope (SEM) have been used to characterize as well as optimize the growth process. Electron beam induced current (EBIC) characterization has also been performed, indicating defect densities as low as 5 x 104/cm{sup 2}. Secondary ion beam mass spectrometry (SIMS) data shows that these layers have reasonable impurity levels within the constraints of the current deposition system. Both n and p-type layers were grown, and p/n diodes have been fabricated.

Thiesen, J.; Jones, K.M.; Matson, R.; Reedy, R.; Crandall, R.; Iwaniczko, E.; Mahan, H.

1999-12-13T23:59:59.000Z

322

CCE CHEMICAL SAFETY MANUAL CHEMICAL SAFETY MANUAL  

E-Print Network (OSTI)

. Chemicals--Safety measures. 3. Hazardous wastes. I. National Research Council (U.S.). Committee on Prudent) produced two major reports on laboratory safety and laboratory waste disposal: Prudent Practices Nanomaterials, 77 4.G Biohazards, 79 4.H Hazards from Radioactivity, 79 5 Management of Chemicals 83 5.A

Tai, Yu-Chong

323

Chemical Reference Data Group Homepage  

Science Conference Proceedings (OSTI)

Chemical Reference Data Group. Welcome. The Chemical Reference Data Group compiles, evaluates, correlates and measures ...

2013-07-10T23:59:59.000Z

324

Elbow mass flow meter  

SciTech Connect

Elbow mass flow meter. The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity.

McFarland, Andrew R. (College Station, TX); Rodgers, John C. (Santa Fe, NM); Ortiz, Carlos A. (Bryan, TX); Nelson, David C. (Santa Fe, NM)

1994-01-01T23:59:59.000Z

325

Extending the frontiers of mass spectrometric instrumentation and methods  

SciTech Connect

The focus of this dissertation is two-fold: developing novel analysis methods using mass spectrometry and the implementation and characterization of a novel ion mobility mass spectrometry instrumentation. The novel mass spectrometry combines ion trap for ion/ion reactions coupled to an ion mobility cell. The long term goal of this instrumentation is to use ion/ion reactions to probe the structure of gas phase biomolecule ions. The three ion source - ion trap - ion mobility - qTOF mass spectrometer (IT - IM - TOF MS) instrument is described. The analysis of the degradation products in coal (Chapter 2) and the imaging plant metabolites (Appendix III) fall under the methods development category. These projects use existing commercial instrumentation (JEOL AccuTOF MS and Thermo Finnigan LCQ IT, respectively) for the mass analysis of the degraded coal products and the plant metabolites, respectively. The coal degradation paper discusses the use of the DART ion source for fast and easy sample analysis. The sample preparation consisted of a simple 50 fold dilution of the soluble coal products in water and placing the liquid in front of the heated gas stream. This is the first time the DART ion source has been used for analysis of coal. Steven Raders under the guidance of John Verkade came up with the coal degradation projects. Raders performed the coal degradation reactions, worked up the products, and sent them to me. Gregg Schieffer developed the method and wrote the paper demonstrating the use of the DART ion source for the fast and easy sample analysis. The plant metabolite imaging project extends the use of colloidal graphite as a sample coating for atmospheric pressure LDI. DC Perdian and I closely worked together to make this project work. Perdian focused on building the LDI setup whereas Schieffer focused on the MSn analysis of the metabolites. Both Perdian and I took the data featured in the paper. Perdian was the primary writer of the paper and used it as a chapter in his dissertation. Perdian and Schieffer worked together to address the revisions and publish it in Rapid Communications in Mass Spectrometry Journal.

Schieffer, Gregg

2010-12-15T23:59:59.000Z

326

Chemical Lifecycle Management Cost  

NLE Websites -- All DOE Office Websites (Extended Search)

Chemical Lifecycle Management Cost Presented by: J.M. Hieb, CH2M HILL Plateau Remediation Company CHPRC1204-04 Chemical Lifecycle Management Cost Everyone is trying to stretch a...

327

Chemical Physics Portal  

Science Conference Proceedings (OSTI)

... spectroscopy. Ultrafast lasers are used to … more. >> see all Chemical Physics programs and projects ... *. Bookmark and Share. ...

2010-10-01T23:59:59.000Z

328

Chemical Sciences Division - CSD  

NLE Websites -- All DOE Office Websites (Extended Search)

CSD Chemical Sciences Division CSD Organization Contact List Search Other Links Research Areas Research Highlights Organization Contacts Publications Awards Employment...

329

PhD Chemical Engineering MS Chemical Engineering  

E-Print Network (OSTI)

1 PhD Chemical Engineering MS Chemical Engineering Bylaws Gene and Linda Voiland School of ChemicalD Chemical Engineering, MS Chemical Engineering B. Discipline: Edgar, et al.1 provide a succinct description of chemical engineering: "chemical engineers seek to understand, manipulate, and control the molecular basis

Collins, Gary S.

330

A Scanning Frequency Mode for Ion Cyclotron Mobility Spectrometry  

E-Print Network (OSTI)

A new operational mode for an ion cyclotron mobility spectrometry instrument is explored as a possibleA Scanning Frequency Mode for Ion Cyclotron Mobility Spectrometry Rebecca S. Glaskin, Stephen J that are applied to segmented regions of a circular drift tube. Ions with mobilities that are resonant

Clemmer, David E.

331

CHEMICAL SAFETY Emergency Numbers  

E-Print Network (OSTI)

- 1 - CHEMICAL SAFETY MANUAL 2010 #12;- 2 - Emergency Numbers UNBC Prince George Campus Security Prince George Campus Chemstores 6472 Chemical Safety 6472 Radiation Safety 5530 Biological Safety 5530 use, storage, handling, waste and emergency management of chemicals on the University of Northern

Bolch, Tobias

332

Chemical biology drug discovery  

E-Print Network (OSTI)

Keywords Chemical biology drug discovery high-throughput screening protein ligands proteases novel chemical and biochemical methods for the identification and optimization of protein ligands us of pro- tein ligands. Results of this research are translated into protein-specific, chemical probes

SchĂĽler, Axel

333

Chemical engineering Research !!  

E-Print Network (OSTI)

Chemical engineering Research !! www.chemeng.lth.se Updated August 2012 #12;WWT Fermentation University/Faculty of Engineering-LTH/Department of Chemical Engineering Membrane Group Ann-Sofi Jönsson More research projects. #12;Lund University/Faculty of Engineering-LTH/Department of Chemical Engineering

334

Chemical Zeolites Combinatorial . . .  

E-Print Network (OSTI)

Chemical Zeolites Combinatorial . . . Realization 2d Zeolites Finite Zeolites The Layer . . . Holes University (Brigitte Servatius -- WPI) #12;Chemical Zeolites Combinatorial . . . Realization 2d Zeolites. Chemical Zeolites · crystalline solid · units: Si + 4O Si O O O O · two covalent bonds per oxygen #12

Servatius, Brigitte

335

CHEMICAL AND PAPER ENGINEERING  

E-Print Network (OSTI)

SAFETY HANDBOOK For CHEMICAL AND PAPER ENGINEERING 2010-2011 #12;Page 1 Safety Guidelines Department of Chemical and Paper Engineering Miami University - Oxford, Ohio 45056 The following safety and Laboratory Coordinator Responsibilities III. Emergency Procedures IV. Chemical Storage V. Routine

Dollar, Anna

336

CCE CHEMICAL SAFETY MANUAL CHEMICAL SAFETY MANUAL  

E-Print Network (OSTI)

. . . . . . . . . . . . . . . . . . . . . 11 VIII. Electrical Equipment . . . . . . . . . . . . . . . . . . . . . . . . 12 IX. Hazardous Waste: Hazardous Chemicals Data . . . . . . . . . . . . . . . . . . 51 Appendix B: Means of Lab Waste Disposal . . . . . . . . . . . . . . . . . 53 Appendix C: Where to put specific wastes . . . . . . . . . . . . . . . . . . 54 Appendix D

Elowitz, Michael

337

The Multiplexed Chemical Kinetic Photoionization Mass Spectrometer: A New Approach To Isomer-resolved Chemical Kinetics  

E-Print Network (OSTI)

Facility, Mail Stop 9055, Sandia National Laboratories,the U.S. Department of Energy. Sandia is a multiprogramlaboratory operated by Sandia Corporation, a Lockheed Martin

Osborne, David L.

2009-01-01T23:59:59.000Z

338

Thermogravimetry-Mass Spectrometry for Carbon Nanotube Detection in Complex Mixtures  

E-Print Network (OSTI)

In spite of the growth of the carbon nanotube (CNT) industry, there are no established analytical methods with which to detect or quantify CNTs in environmental matrices. Given that CNTs have relatively high thermal ...

Plata, Desiree Louise

339

Application of Mass Spectrometry on Quantitative Proteomics and Histone Post-Translational Modifications  

E-Print Network (OSTI)

Probable ATP-dependent RNA helicase DDX5 IPI00220373.3Probable ATP-dependent RNA helicase DDX5 IPI00023748.3IPI00215637.4 ATP-dependent RNA helicase DDX3X IPI00010700.2

Xiong, Lei

2011-01-01T23:59:59.000Z

340

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network (OSTI)

Attribution and Non-Proliferation Applications”, IEEETreaty on the Non-Proliferation of Nuclear Weapons (NPT)”,as detailed in the Non-Proliferation Treaty (NPT), is to

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

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.


341

Kinetics of laser pulse vaporization of uranium dioxide by mass spectrometry  

Science Conference Proceedings (OSTI)

Safety analyses of nuclear reactors require knowledge of the evaporation behavior of UO/sub 2/ at temperatures well above the melting point of 3140 K. In this study, rapid transient heating of a small spot on a UO/sub 2/ specimen was accomplished by a laser pulse, which generates a surface temperature excursion. This in turn vaporizes the target surface and the gas expands into vacuum. The surface temperature transient was monitored by a fast-response automatic optical pyrometer. The maximum surface temperatures investigated range from approx. 3700 K to approx. 4300 K. A computer program was developed to simulate the laser heating process and calculate the surface temperature evolution. The effect of the uncertainties of the high temperature material properties on the calculation was included in a sensitivity study for UO/sub 2/ vaporization. The measured surface temperatures were in satisfactory agreements.

Tsai, C.

1981-11-01T23:59:59.000Z

342

Mass Spectrometry Based Method Development for Elucidation of Protein Sequences, Structures and Post Translational Modifications  

E-Print Network (OSTI)

Covelli, I. ; Wolff, J. J. Bio. Chem. 1967, 242, 881-886.A. ; Yates, J. R. Curr. Opin. Chem. Bio. 2008, 12, 483-490.

Sun, Qingyu

2011-01-01T23:59:59.000Z

343

Anthropogenic particulate source characterization and source apportionment using aerosol time-of-flight mass spectrometry  

E-Print Network (OSTI)

vehicles, biomass burning, coal combustion, meat cooking,Arabia: biomass/biofuel burning and fossil fuel combustion,Arabia: biomass/biofuel burning and fossil fuel combustion,

Toner, Stephen Mark

2007-01-01T23:59:59.000Z

344

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

Office of Science (SC) Website

important application of AMS measurements of the naturally occurring 36ClCl ratio in water (as opposed to the one created by atmospheric and underground nuclear weapons test) is...

345

Development and application of mass spectrometry-based metabolomics methods for disease biomarker identification  

E-Print Network (OSTI)

Human societies face diverse health challenges including a rapidly aging population, rising incidence of metabolic disease, and increasing antibiotic resistance. These problems involve complex interactions between genes ...

Tong, Lily Victoria

2008-01-01T23:59:59.000Z

346

New mass spectrometry techniques for studying physical chemistry of atmospheric heterogeneous processes  

E-Print Network (OSTI)

ion mode DESI and nano-DESI result in the formation of protonated molecules [M + H]+ and molecules cationised on metals, such as sodium [M + Na]+ adducts, while deprotonated [M Ă? H]Ă? molecules are observed+ ) reacts selectively with molecules (M) containing carbonyl groups, such as aldehydes and ketones [79

Nizkorodov, Sergey

347

High resolution mass spectrometry method and system for analysis of whole proteins and other large molecules  

DOE Patents (OSTI)

A matrix assisted laser desorption/ionization (MALDI) method and related system for analyzing high molecular weight analytes includes the steps of providing at least one matrix-containing particle inside an ion trap, wherein at least one high molecular weight analyte molecule is provided within the matrix-containing particle, and MALDI on the high molecular weight particle while within the ion trap. A laser power used for ionization is sufficient to completely vaporize the particle and form at least one high molecular weight analyte ion, but is low enough to avoid fragmenting the high molecular weight analyte ion. The high molecular weight analyte ion is extracted out from the ion trap, and is then analyzed using a detector. The detector is preferably a pyrolyzing and ionizing detector.

Reilly, Peter T. A. (Knoxville, TN); Harris, William A. (Naperville, IL)

2010-03-02T23:59:59.000Z

348

Facilitation of protein 3-D structure determination using enhanced peptide amide deuterium exchange mass spectrometry (DXMS)  

E-Print Network (OSTI)

metalloproteinase inhibitor doxycycline investigated bymetalloproteinase inhibitor doxycycline investigated byand Nagasue N (2004) Doxycycline inhibits cell proliferation

Pantazatos, Dennis Peter

2006-01-01T23:59:59.000Z

349

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network (OSTI)

Proliferation of Nuclear Weapons (NPT)”, http: //www.un.org/end of the Cold War, nuclear weapons remain at the heart ofthe spread of nuclear weapons, analysis of nuclear materials

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

350

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network (OSTI)

as detailed in the Non-Proliferation Treaty (NPT), is toUnited Nations, “Treaty on the Non-Proliferation of Nuclear

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

351

Characterization of the Molecular Composition of Secondary Organic Aerosols using High Resolution Mass Spectrometry  

E-Print Network (OSTI)

in secondary organic aerosol formation from isoprene, Proc.biogenic secondary organic aerosol, J. Phys. Chem. A, 112(in secondary organic aerosol, Environ. Sci. Technol. , 41(

Sellon, Rachel Elizabeth

2012-01-01T23:59:59.000Z

352

Computational mass spectrometry : algorithms for identification of peptides not present in protein databases  

E-Print Network (OSTI)

Pereira, W. -T. Liu, J. Ng, P. A. Pevzner, P. C. Dorrestein,11188, 2010. W. -T. Liu, J. Ng, D. Meluzzi, N. Bandeira, M.no. 11, pp. 4200-4209, J. Ng, N. Bandeira, W. -T. Liu, M.

Ng, Julio

2011-01-01T23:59:59.000Z

353

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network (OSTI)

Pakistan is exacerbated by concerns over both terrorist activity and the security of its rapidly increasing nuclear

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

354

Engineering model reduction of bio-chemical kinetic David Csercsik, Katalin M. Hangos  

E-Print Network (OSTI)

of Hydrosystems Chemical and Thermal Non-Equilibrium: Kinetic Mass & Energy Transfer Motivation Modeling Non is actually driven by difference in chemical potential influence of thermal non-equilibrium on kinetic mass situation of clear non-equilibrium extending range of applicability Support of the German Research

Gorban, Alexander N.

355

Chemical exchange program analysis.  

SciTech Connect

As part of its EMS, Sandia performs an annual environmental aspects/impacts analysis. The purpose of this analysis is to identify the environmental aspects associated with Sandia's activities, products, and services and the potential environmental impacts associated with those aspects. Division and environmental programs established objectives and targets based on the environmental aspects associated with their operations. In 2007 the most significant aspect identified was Hazardous Materials (Use and Storage). The objective for Hazardous Materials (Use and Storage) was to improve chemical handling, storage, and on-site movement of hazardous materials. One of the targets supporting this objective was to develop an effective chemical exchange program, making a business case for it in FY07, and fully implementing a comprehensive chemical exchange program in FY08. A Chemical Exchange Program (CEP) team was formed to implement this target. The team consists of representatives from the Chemical Information System (CIS), Pollution Prevention (P2), the HWMF, Procurement and the Environmental Management System (EMS). The CEP Team performed benchmarking and conducted a life-cycle analysis of the current management of chemicals at SNL/NM and compared it to Chemical Exchange alternatives. Those alternatives are as follows: (1) Revive the 'Virtual' Chemical Exchange Program; (2) Re-implement a 'Physical' Chemical Exchange Program using a Chemical Information System; and (3) Transition to a Chemical Management Services System. The analysis and benchmarking study shows that the present management of chemicals at SNL/NM is significantly disjointed and a life-cycle or 'Cradle-to-Grave' approach to chemical management is needed. This approach must consider the purchasing and maintenance costs as well as the cost of ultimate disposal of the chemicals and materials. A chemical exchange is needed as a mechanism to re-apply chemicals on site. This will not only reduce the quantity of unneeded chemicals and the amount spent on new purchases, but will also avoid disposal costs. If SNL/NM were to realize a 5 percent reduction in chemical inventory and a 10 percent reduction in disposal of unused chemicals the total savings would be $189, 200 per year.

Waffelaert, Pascale

2007-09-01T23:59:59.000Z

356

Siphons in Chemical Reaction Networks  

E-Print Network (OSTI)

credited. Siphons in Chemical Reaction Networks Referencesfor a class of nonlinear chemical equations. SIAM J. Appl.to persistence analysis in chemical reaction networks. In:

Shiu, Anne; Sturmfels, Bernd

2010-01-01T23:59:59.000Z

357

Chemical Hygiene and Safety Plan  

E-Print Network (OSTI)

V. , Ed. , Safety in the Chemical Laboratory. J. Chem.Łd. Amer/can Chemical Society. Easlon. PA. 18042. Vol. Lof Laboratory Safety. the Chemical Rubber Company Cleveland.

Ricks Editor, R.

2009-01-01T23:59:59.000Z

358

Mass independent kinetic energy reducing inlet system for vacuum environment  

Science Conference Proceedings (OSTI)

A particle inlet system comprises a first chamber having a limiting orifice for an incoming gas stream and a micrometer controlled expansion slit. Lateral components of the momentum of the particles are substantially cancelled due to symmetry of the configuration once the laminar flow converges at the expansion slit. The particles and flow into a second chamber, which is maintained at a lower pressure than the first chamber, and then moves into a third chamber including multipole guides for electromagnetically confining the particle. The vertical momentum of the particles descending through the center of the third chamber is minimized as an upward stream of gases reduces the downward momentum of the particles. The translational kinetic energy of the particles is near-zero irrespective of the mass of the particles at an exit opening of the third chamber, which may be advantageously employed to provide enhanced mass resolution in mass spectrometry.

Reilly, Peter T. A. [Knoxville, TN

2010-12-14T23:59:59.000Z

359

Physical and chemical characterization of Dead Sea mud  

SciTech Connect

A laboratory analysis was performed to determine the physical and chemical properties of 24 Dead Sea mud samples collected from three different locations on the eastern shore of the Dead Sea. Several analytical techniques were used to determine the chemical and mineralogical compositions of those samples including atomic absorption spectrometry and X-ray diffraction. Physical parameters such as specific gravity, Atterberg limits, grain size, specific surface area, cation exchange capacity, pH and electrical conductivity were also studied. The main focus of the work was to document mud characteristics and to study the interrelation between physical and chemical properties. The mud samples were quite rich in minerals. Strontium was the most abundant trace element in the samples (range: 410-810 ppm) followed by barium (range: 155-380 ppm), vanadium (range: 209-264 ppm) and lead (range: 108-114 ppm). There were significant differences in the elemental contents of mud samples collected from different locations.

Khlaifat, Abdelaziz, E-mail: abdelaziz.khlaifat@me.weatherford.com [Weatherford Oil Tool Middle East Ltd., P.O. Box 4627, Dubai (United Arab Emirates); Al-Khashman, Omar [Department of Environmental Engineering, Al-Hussein Bin Talal University, Ma'an, P.O. Box 20 (Jordan); Qutob, Hani [Weatherford Oil Tool Middle East Ltd., P.O. Box 4627, Dubai (United Arab Emirates)

2010-05-15T23:59:59.000Z

360

Does Information Have Mass?  

E-Print Network (OSTI)

Does information have mass? This question has been asked many times and there are many answers even on the Internet, including on Yahoo Answers. Usually the answer is "no". Attempts have been made to assess the physical mass of information by estimating the mass of electrons feeding the power-guzzling computers and devices making up the Internet, the result being around 50 gram. Other efforts to calculate the mass of information have assumed that each electron involved in signal transfer carries one bit of information, which makes the corresponding mass to be about 10^-5 gram. We address the fundamental question of minimum mass related to a bit of information from the angles of quantum physics and special relativity. Our results indicate that there are different answers depending on the physical situation, and sometimes the mass can even be negative. We tend to be skeptical about the earlier mass estimations, mentioned above, because our results indicate that the electron's mass does not play a role in any on...

Kish, Laszlo B

2013-01-01T23:59:59.000Z

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.


361

Mass-Loaded Flows  

E-Print Network (OSTI)

A key process within astronomy is the exchange of mass, momentum, and energy between diffuse plasmas in many types of astronomical sources (including planetary nebulae, wind-blown bubbles, supernova remnants, starburst superwinds, and the intracluster medium) and dense, embedded clouds or clumps. This transfer affects the large scale flows of the diffuse plasmas as well as the evolution of the clumps. I review our current understanding of mass-injection processes, and examine intermediate-scale structure and the global effect of mass-loading on a flow. I then discuss mass-loading in a variety of diffuse sources.

J. M. Pittard

2006-07-13T23:59:59.000Z

362

S-systems and Evolutionary Algorithms for the Inference of Chemical Reaction Networks from Fed-Batch Reactor Experiments  

E-Print Network (OSTI)

chemical entities is a kinetic model of the reaction system. Once obtained, this allows the chemical of mass action kinetics, the rate of change of concentration due to chemical reaction of each species of reaction vessel models, whereas without detailed chemical mechanism and kinetic studies, the form

Newcastle upon Tyne, University of

363

Chemical evolution STRUCTURE OF GALAXIES  

E-Print Network (OSTI)

Outline Absorption Chemical evolution STRUCTURE OF GALAXIES 8. Absorption; chemical evolution Piet Piet van der Kruit, Kapteyn Astronomical Institute Absorption; chemical evolution #12;Outline Absorption Chemical evolution Outline Absorption Holmberg's analysis Analysis of Disney et al. Edge

Kruit, Piet van der

364

Chemical Structure and Dynamics  

NLE Websites -- All DOE Office Websites (Extended Search)

2154-3 2154-3 UC-400 Annual Report 2000 Chemical Structure and Dynamics Steven D. Colson, Associate Director Robin S. McDowell, Program Manager and the Staff of the Chemical Structure and Dynamics Program April 2001 Prepared for the U.S. Department of Energy under Contract DE-AC06-76RL01830 Chemical Structure and Dynamics 2000 Annual Report Contents Chemical Structure and Dynamics 2000 Annual Report Chemical Structure and Dynamics 2000 Annual Report 1. Introduction Chemical Structure and Dynamics Program......................................................... 1-3 2. Reaction Mechanisms at Liquid Interfaces Structure and Reactivity of Ice Surfaces and Interfaces G. A. Kimmel, Z. Dohnálek, K. P. Stevenson, R. S. Smith,

365

Ion-mobility Spectrometry Based NOx Sensor - Nuclear Engineering Division  

NLE Websites -- All DOE Office Websites (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

366

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

367

On the Photon Mass  

E-Print Network (OSTI)

We review the case for the photon having a tiny mass compatible with the experimental limits. We go over some possible experimental tests for such a photon mass including the violation of Lorentz symmetry. We point out that such violations may already have been witnessed in tests involving high energy gamma rays from outer space as also ultra high energy cosmic rays.

Burra G. Sidharth

2007-06-22T23:59:59.000Z

368

Thermal masses in leptogenesis  

E-Print Network (OSTI)

We investigate the validity of using thermal masses in the kinematics of final states in the decay rate of heavy neutrinos in leptogenesis calculations. We find that using thermal masses this way is a reasonable approximation, but corrections arise through quantum statistical distribution functions and leptonic quasiparticles.

Kiessig, Clemens P

2009-01-01T23:59:59.000Z

369

Elbow mass flow meter  

DOE Patents (OSTI)

The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity. 3 figs.

McFarland, A.R.; Rodgers, J.C.; Ortiz, C.A.; Nelson, D.C.

1994-08-16T23:59:59.000Z

370

The origin of mass  

Science Conference Proceedings (OSTI)

The origin of mass is one of the deepest mysteries in science. Neutrons and protons, which account for almost all visible mass in the Universe, emerged from a primordial plasma through a cataclysmic phase transition microseconds after the Big Bang. However, ... Keywords: Gordon Bell Prize categories: scalability and time to solution, SC13 proceedings

Peter Boyle, Michael I. Buchoff, Norman Christ, Taku Izubuchi, Chulwoo Jung, Thomas C. Luu, Robert Mawhinney, Chris Schroeder, Ron Soltz, Pavlos Vranas, Joseph Wasem

2013-11-01T23:59:59.000Z

371

Percent Yield and Mass of Water  

NLE Websites -- All DOE Office Websites (Extended Search)

Percent Yield and Mass of Water Percent Yield and Mass of Water Name: Lisa Status: educator Grade: 9-12 Location: CA Country: USA Date: Winter 2011-2012 Question: When doing a percent yield activity in lab, we use MgCl hexahydrate and CaSO4. How do we factor the mass of the water that is released during the reaction? Replies: Lisa, Based on your question, I am not quite sure what the experiment is. Are you heating the hydrates and looking at the percent-yield of water removed during the heating? If so, then you would calculate the theoretical yield (using stoichiometry and the balanced chemical equation: MgCl2.6H2O --> MgCl2 + 6H2O) of water released, and compare it to the actual yield of water released in the experiment to get percent yield. Greg (Roberto Gregorius) Canisius College

372

Portable gas chromatograph-mass spectrometer  

DOE Patents (OSTI)

A gas chromatograph-mass spectrometer (GC-MS) for use as a field portable organic chemical analysis instrument. The GC-MS is designed to be contained in a standard size suitcase, weighs less than 70 pounds, and requires less than 600 watts of electrical power at peak power (all systems on). The GC-MS includes: a conduction heated, forced air cooled small bore capillary gas chromatograph, a small injector assembly, a self-contained ion/sorption pump vacuum system, a hydrogen supply, a dual computer system used to control the hardware and acquire spectrum data, and operational software used to control the pumping system and the gas chromatograph. This instrument incorporates a modified commercial quadrupole mass spectrometer to achieve the instrument sensitivity and mass resolution characteristic of laboratory bench top units.

Andresen, B.D.; Eckels, J.D.; Kimmins, J.F.; Myers, D.W.

1994-12-31T23:59:59.000Z

373

ENHANCED CHEMICAL CLEANING CORROSION TESTING  

Enhanced Chemical Cleaning Corrosion Testing 3 Background: Enhanced Chemical Cleaning Process Treatment Tank Deposition Tank 3000 gpm Mixers Oxalic ...

374

Chemical Hygiene and Safety Plan  

E-Print Network (OSTI)

Safety Plan m Chemical$torase Guidelines Chemical Is Incompatible llll i With ii Hydrocarbons (such as butane, propane,

Ricks Editor, R.

2009-01-01T23:59:59.000Z

375

W Transverse Mass  

NLE Websites -- All DOE Office Websites (Extended Search)

Some Data Analysis Some Data Analysis The Tevatron produces millions of collisions each second in CDF and DZero. The detectors have hardware triggers to decide if a collision is "interesting," that is it contains a candidate event for any one of a number studies. Our dataset contains 48,844 candidate events for a W mass study. There are other datasets to study Z mass, top and b quarks, QCD, etc. Why don't all the W decays give exactly the same mass? Are all these candidates really Ws? What if we chose only some of these data. How would our choice effect the value of the transverse mass? Work with your classmates. Test the data to see what you can learn. Help with data analysis. Record the best estimate of the W transverse mass from your data analysis. Explain which data you used and why. Check with your classmates and explain any differences between your estimate and theirs.

376

Chemical Testing of Textiles  

Science Conference Proceedings (OSTI)

Chemical Testing of Textiles is edited by Qinguo Fan and covers more subjects than the title implies. These subjects include fiber and yarn identification, ...

377

American Chemical Society  

Science Conference Proceedings (OSTI)

*. Bookmark and Share. American Chemical Society (ACS). Purpose: Air and water mediate chemistry on Earth. ... Related Project(s): ACS. Details: ...

2011-08-29T23:59:59.000Z

378

Apparatus for chemical synthesis  

DOE Patents (OSTI)

A method and apparatus for forming a chemical hydride is described and which includes a pseudo-plasma-electrolysis reactor which is operable to receive a solution capable of forming a chemical hydride and which further includes a cathode and a movable anode, and wherein the anode is moved into and out of fluidic, ohmic electrical contact with the solution capable of forming a chemical hydride and which further, when energized produces an oxygen plasma which facilitates the formation of a chemical hydride in the solution.

Kong, Peter C. (Idaho Falls, ID); Herring, J. Stephen (Idaho Falls, ID); Grandy, Jon D. (Idaho Falls, ID)

2011-05-10T23:59:59.000Z

379

Chemical Sciences Division  

NLE Websites -- All DOE Office Websites (Extended Search)

& CENTERS RESEARCH STUDENT & POSTDOCTORAL OPPORTUNITIES NEWS & EVENTS CSD CONTACTS LBNL HOME logo Privacy & Security Notice DOE UC Berkeley Chemical Sciences Division imagemap...

380

Chemical Name Search  

Science Conference Proceedings (OSTI)

... Enter a chemical species name or pattern: (eg, methane, *2-hexene); Select the desired units for thermodynamic data: SI calorie-based; ...

2013-07-15T23:59:59.000Z

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.


381

Biomass pyrolysis for chemicals.  

E-Print Network (OSTI)

??Biomass Pyrolysis for Chemicals The problems associated with the use of fossil fuels demand a transition to renewable sources (sun, wind, water, geothermal, biomass) for… (more)

Wild, Paul de

2011-01-01T23:59:59.000Z

382

Brookhaven Chemical Physics  

NLE Websites -- All DOE Office Websites (Extended Search)

Chemical Physics While the field of physics generally strives to find compact and universal explanations for how the components of our universe interact, chemistry is traditionally...

383

MassMass transfer andtransfer and arationstearationste  

E-Print Network (OSTI)

, temperature, T, and energy, E, are scalars and their gradient is a vector dc/dx or arationste scalars diffusion coefficient D; for species A in medium B : D = DAB 4 erföringo dx dc D dt.A dm m Massöve c cSepa dx dc )DD(m th Irreversible Thermodynamics considers Thermo-diffusion 4 erföringo T T Thermo

Zevenhoven, Ron

384

Amplitude and phase?modulation (AM?PM) wide?band photothermal spectrometry. II. Experiment  

Science Conference Proceedings (OSTI)

Amplitude and phase?modulation (AM?PM) wide?band photothermal spectrometry is experimentally demonstrated

J. F. Power

1990-01-01T23:59:59.000Z

385

Dynamical and chemical evolution of NGC1569  

E-Print Network (OSTI)

Blue Compact Dwarf and Dwarf Irregular galaxies are generally believed to be unevolved objects, due to their blue colors, compact appearance and large gas fractions. Many of these objects show an ongoing intense burst of star formation or have experienced it in the recent past. By means of 2-D hydrodynamical simulations, coupled with detailed chemical yields originating from SNeII, SNeIa, and intermediate-mass stars, we study the dynamical and chemical evolution of model galaxies with structural parameters similar to NGC1569, a prototypical starburst galaxy. A burst of star formation with short duration is not able to account for the chemical and morphological properties of this galaxy. The best way to reproduce the chemical composition of this object is by assuming long-lasting episodes of star formation and a more recent burst, separated from the previous episodes by a short quiescent period. The last burst of star formation, in most of the explored cases, does not affect the chemical composition of the galaxy, since the enriched gas produced by young stars is in a too hot phase to be detectable with the optical spectroscopy. Models assuming the infall of a big cloud towards the center of the galaxy reproduce the chemical composition of the NGC1569, but the pressure exercised by the cloud hampers the expansion of the galactic wind, at variance with what observed in NGC1569.

S. Recchi; G. Hensler; L. Angeretti; F. Matteucci

2005-09-14T23:59:59.000Z

386

Atoms of multistationarity in chemical reaction networks  

E-Print Network (OSTI)

Chemical reaction networks taken with mass-action kinetics are dynamical systems that arise in chemical engineering and systems biology. Deciding whether a chemical reaction network admits multiple positive steady states is to determine existence of multiple positive solutions to a system of polynomials with unknown coefficients. In this work, we consider the question of whether the minimal (in a precise sense) networks, which we propose to call `atoms of multistationarity,' characterize the entire set of multistationary networks. We show that if a subnetwork admits multiple nondegenerate positive steady states, then these steady states can be extended to establish multistationarity of a larger network, provided that the two networks share the same stoichiometric subspace. Our result provides the mathematical foundation for a technique used by Siegal-Gaskins et al. of establishing bistability by way of `network ancestry.' Here, our main application is for enumerating small multistationary continuous-flow stir...

Joshi, Badal

2011-01-01T23:59:59.000Z

387

Sludge Mass Reduction Update  

NLE Websites -- All DOE Office Websites (Extended Search)

Chemical Cleaning Chemical Cleaning Edward T. Ketusky Technology Development Engineering Washington Savannah River Company U.S. Department of Energy Office of Waste Processing Technical Exchange May 20, 2009 Enhanced Chemical Cleaning Edward T. Ketusky Technology Development Engineering Washington Savannah River Company U.S. Department of Energy Office of Waste Processing Technical Exchange May 20, 2009 3 Overview * SRS has taken a pro-active approach to meeting regulatory guidelines for tank closure by developing & implementing innovative technologies * Based on an exhaustive search for an alternatives to bulk oxalic acid (OA), and a switch to a TRIZ type contradiction trading effort, the Enhanced Chemical Cleaning (ECC) concept was developed * ECC uses dilute OA as the cleaning agent, ozone/UV to

388

Subgiants as probes of galactic chemical evolution  

E-Print Network (OSTI)

Chemical abundances for 23 candidate subgiant stars have been derived with the aim at exploring their usefulness for studies of galactic chemical evolution. High-resolution spectra from ESO CAT-CES and NOT-SOFIN covered 16 different spectral regions in the visible part of the spectrum. Some 200 different atomic and molecular spectral lines have been used for abundance analysis of about 30 elemental species. The wings of strong, pressure-broadened metal lines were used for determination of stellar surface gravities, which have been compared with gravities derived from Hipparcos parallaxes and isochronic masses. Stellar space velocities have been derived from Hipparcos and Simbad data, and ages and masses were derived with recent isochrones. Only 12 of the stars turned out to be subgiants, i.e. on the "horizontal" part of the evolutionary track between the dwarf- and the giant stages. The abundances derived for the subgiants correspond closely to those of dwarf stars. With the possible exceptions of lithium and carbon we find that subgiant stars show no "chemical" traces of post-main-sequence evolution and that they are therefore very useful targets for studies of galactic chemical evolution.

Patrik Thoren; Bengt Edvardsson; Bengt Gustafsson

2004-07-13T23:59:59.000Z

389

TANK 40 FINAL SLUDGE BATCH 8 CHEMICAL CHARACTERIZATION RESULTS  

SciTech Connect

A sample of Sludge Batch 8 (SB8) was pulled from Tank 40 in order to obtain radionuclide inventory analyses necessary for compliance with the Waste Acceptance Product Specifications (WAPS). The SB8 WAPS sample was also analyzed for chemical composition, including noble metals, and fissile constituents, and these results are reported here. These analyses along with the WAPS radionuclide analyses will help define the composition of the sludge in Tank 40 that is currently being fed to the Defense Waste Processing Facility (DWPF) as SB8. At SRNL, the 3-L Tank 40 SB8 sample was transferred from the shipping container into a 4-L high density polyethylene bottle and solids were allowed to settle. Supernate was then siphoned off and circulated through the shipping container to complete the transfer of the sample. Following thorough mixing of the 3-L sample, a 553 g sub-sample was removed. This sub-sample was then utilized for all subsequent slurry sample preparations. Eight separate aliquots of the slurry were digested, four with HNO{sub 3}/HCl (aqua regia) in sealed Teflon? vessels and four with NaOH/Na{sub 2}O{sub 2} (alkali or peroxide fusion) using Zr crucibles. Two Analytical Reference Glass ? 1 (ARG-1) standards were digested along with a blank for each preparation. Each aqua regia digestion and blank was diluted to 1:100 mL with deionized water and submitted to Analytical Development (AD) for inductively coupled plasma ? atomic emission spectroscopy (ICP-AES) analysis, inductively coupled plasma ? mass spectrometry (ICP-MS) analysis, atomic absorption spectroscopy (AA) for As and Se, and cold vapor atomic absorption spectroscopy (CV-AA) for Hg. Equivalent dilutions of the alkali fusion digestions and blank were submitted to AD for ICP-AES analysis. Tank 40 SB8 supernate was collected from a mixed slurry sample in the SRNL Shielded Cells and submitted to AD for ICP-AES, ion chromatography (IC), total base/free OH-/other base, total inorganic carbon/total organic carbon (TIC/TOC) analyses. Weighted dilutions of slurry were submitted for IC, TIC/TOC, and total base/free OH-/other base analyses. Activities for U-233, U-235, and Pu-239 were determined from the ICP-MS data for the aqua regia digestions of the Tank 40 WAPS slurry using the specific activity of each isotope. The Pu-241 value was determined from a Pu-238/-241 method developed by SRNL AD and previously described.

Bannochie, C.

2013-09-19T23:59:59.000Z

390

Tank 40 Final SB7b Chemical Characterization Results  

SciTech Connect

A sample of Sludge Batch 7b (SB7b) was taken from Tank 40 in order to obtain radionuclide inventory analyses necessary for compliance with the Waste Acceptance Product Specifications (WAPS). The SB7b WAPS sample was also analyzed for chemical composition including noble metals and fissile constituents. At the Savannah River National Laboratory (SRNL) the 3-L Tank 40 SB7b sample was transferred from the shipping container into a 4-L high density polyethylene bottle and solids were allowed to settle over the weekend. Supernate was then siphoned off and circulated through the shipping container to complete the transfer of the sample. Following thorough mixing of the 3-L sample, a 558 g sub-sample was removed. This sub-sample was then utilized for all subsequent analytical samples. Eight separate aliquots of the slurry were digested, four with HNO{sub 3}/HCl (aqua regia) in sealed Teflon? vessels and four with NaOH/Na{sub 2}O{sub 2} (alkali or peroxide fusion) using Zr crucibles. Two Analytical Reference Glass ? 1 (ARG-1) standards were digested along with a blank for each preparation. Each aqua regia digestion and blank was diluted to 1:100 mL with deionized water and submitted to Analytical Development (AD) for inductively coupled plasma ? atomic emission spectroscopy (ICP-AES) analysis, inductively coupled plasma ? mass spectrometry (ICP-MS) analysis, atomic absorption spectroscopy (AA) for As and Se, and cold vapor atomic absorption spectroscopy (CV-AA) for Hg. Equivalent dilutions of the alkali fusion digestions and blank were submitted to AD for ICP-AES analysis. Tank 40 SB7b supernate was collected from a mixed slurry sample in the SRNL Shielded Cells and submitted to AD for ICP-AES, ion chromatography (IC), total base/free OH{sup -}/other base, total inorganic carbon/total organic carbon (TIC/TOC) analyses, and Cs-137 gamma scan. Weighted dilutions of slurry were submitted for IC, TIC/TOC, and total base/free OH-/other base analyses. Activities for U-233, U-235, and Pu-239 were determined from the ICP-MS data for the aqua regia digestions of the Tank 40 WAPS slurry using the specific activity of each isotope. The Pu-241 value was determined from a Pu-238/-241 method.

Bannochie, C. J.

2012-11-06T23:59:59.000Z

391

Chemical Plume Source Localization  

Science Conference Proceedings (OSTI)

This paper addresses the problem of estimating a likelihood map for the location of the source of a chemical plume using an autonomous vehicle as a sensor probe in a fluid flow. The fluid flow is assumed to have a high Reynolds number. Therefore, the ... Keywords: Autonomous vehicles, Bayesian inference methods, chemical plume tracing, online mapping, online planning, plume source localization

Shuo Pang; J. A. Farrell

2006-10-01T23:59:59.000Z

392

Modelling the chemical evolution  

E-Print Network (OSTI)

Advanced observational facilities allow to trace back the chemical evolution of the Universe, on the one hand, from local objects of different ages and, secondly, by direct observations of redshifted objects. The chemical enrichment serves as one of the cornerstones of cosmological evolution. In order to understand this chemical evolution in morphologically different astrophysical objects models are constructed based on analytical descriptions or numerical methods. For the comparison of their chemical issues, as there are element abundances, gradients, and ratios, with observations not only the present-day values are used but also their temporal evolution from the first era of metal enrichment. Here we will provide some insight into basics of chemical evolution models, highlight advancements, and discuss a few applications.

Hensler, Gerhard

2010-01-01T23:59:59.000Z

393

Enhanced Chemical Cleaning  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Chemical Cleaning Chemical Cleaning Renee H. Spires Enhanced Chemical Cleaning Project Manager July 29, 2009 Tank Waste Corporate Board 2 Objective Provide an overview of the ECC process and plan 3 Chemical Cleaning * Oxalic Acid can get tanks clean - Tank 16 set a standard in 1982 - Tanks 5-6 Bulk OA cleaning results under evaluation * However, the downstream flowsheet and financial impacts of handling the spent acid were unacceptable Before After Tank 16 Tank 16 4 Oxalic Acid Flowsheet Impacts Evap Sludge Washing Evap Feed/Drop Tank 8 Wt% Oxalic Acid Neutralization Tank Solids Liquid High oxalate concentration Negligible oxalate concentration * Oxalates from chemical cleaning impact salt processing * A process change was needed Evaporator Saltstone Vaults DWPF Filled Canisters 5 Vision * Eliminate the impacts to the Tank Farm

394

Higgs Mass Calculations  

NLE Websites -- All DOE Office Websites (Extended Search)

this sheet now. Help with data analysis Higgs Mass Plot Project Contact: Thomas Jordan - jordant@fnal.gov Web Maintainer: qnet-webmaster@fnal.gov Last Update: August 22,...

395

Solids mass flow determination  

DOE Patents (OSTI)

Method and apparatus for determining the mass flow rate of solids mixed with a transport fluid to form a flowing mixture. A temperature differential is established between the solids and fluid. The temperature of the transport fluid prior to mixing, the temperature of the solids prior to mixing, and the equilibrium temperature of the mixture are monitored and correlated in a heat balance with the heat capacities of the solids and fluid to determine the solids mass flow rate.

Macko, Joseph E. (Hempfield Township, Westmoreland County, PA)

1981-01-01T23:59:59.000Z

396

Potential long-term chemical effects of diesel fuel emissions on a mining environment: A preliminary assessment based on data from a deep subsurface tunnel at Rainer Mesa, Nevada test site  

SciTech Connect

The general purpose of the Yucca Mountain Site Characterization Project (YMSCP) Introduced Materials Task is to understand and predict potential long-term modifications of natural water chemistry related to the construction and operation of a radioactive waste repository that may significantly affect performance of the waste packages. The present study focuses on diesel exhaust. Although chemical information on diesel exhaust exists in the literature, it is either not explicit or incomplete, and none of it establishes mechanisms that might be used to predict long-term behavior. In addition, the data regarding microbially mediated chemical reactions are not well correlated with the abiotic chemical data. To obtain some of the required long-term information, we chose a historical analog: the U12n tunnel at Rainier Mesa, Nevada Test Site. This choice was based on the tunnel`s extended (30-year) history of diesel usage, its geological similarity to Yucca Mountain, and its availability. The sample site within the tunnel was chosen based on visual inspection and on information gathered from miners who were present during tunnel operations. The thick layer of dark deposit at that site was assumed to consist primarily of rock powder and diesel exhaust. Surface samples and core samples were collected with an intent to analyze the deposit and to measure potential migration of chemical components into the rock. X-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM) with energy dispersive spectra (EDS) analysis, secondary-ion mass spectrometry (SIMS), and Fourier transform infrared (FTIR) analysis were used to measure both spatial distribution and concentration for the wide variety of chemical components that were expected based on our literature survey.

Meike, A.; Bourcier, W.L.; Alai, M. [and others

1995-09-01T23:59:59.000Z

397

W Transverse Mass  

NLE Websites -- All DOE Office Websites (Extended Search)

Transverse Mass Histogram Transverse Mass Histogram Data for 49,844 candidate W events are in an Excel spreadsheet with the following data as shown in the table below: A B C D 1 Run No Event No W TMass GeV/c2 Bins 2 55237 19588 68.71732 3 55237 30799 72.19464 Get the data. Sort the data by ascending mass. Be sure to sort all the data in the first three columns! Make a histogram of the data. Rather than graphing the data as individual points, physicists group the data by mass. They consider the full range of the data and divide it into "bins" of equal range size. A histogram is a graph of the number of events in each bin vs. the bin range. They are looking for a peak in the data where most of the masses fall. This will be the value of the mass as detemined by that dataset, and the width of the distribution is a reflection of the errors in the measurements.

398

Chemical engineers design, control and optimize large-scale chemical,  

E-Print Network (OSTI)

by petition only. 405 Applications of Probability and Statistics for Chemical Engineers (3, Fa) Principles of probability and statistics, random variables and random functions. Application to chemical engineering Chemical Reactor Analysis (3, Fa) Basic concepts of chemical kinetics and chemical reactor design

Wang, Hai

399

Chemical engineers design, control and optimize large-scale chemical,  

E-Print Network (OSTI)

. Enrollment by petition only. CHE 405 Applications of Probability and Statistics for Chemical Engineers (3, Fa) Principles of probability and statistics, random variables and random functions. Application to chemical) CHE 442 Chemical Reactor Analysis (3, Fa) Basic concepts of chemical kinetics and chemical reactor

Wang, Hai

400

Gas mass transfer for stratified flows  

SciTech Connect

We analyzed gas absorption and release in water bodies using existing surface renewal theory. We show a new relation between turbulent momentum and mass transfer from gas to water, including the effects of waves and wave roughness, by evaluating the equilibrum integral turbulent dissipation due to energy transfer to the water from the wind. Using Kolmogoroff turbulence arguments the gas transfer velocity, or mass transfer coefficient, is then naturally and straightforwardly obtained as a non-linear function of the wind speed drag coefficient and the square root of the molecular diffusion coefficient. In dimensionless form, the theory predicts the turbulent Sherwood number to be Sh{sub t} = (2/{radical}{pi}) Sc{sup 1/2}, where Sh{sub t} is based on an integral dissipation length scale in the air. The theory confirms the observed nonlinear variation of the mass transfer coefficient as a function of the wind speed; gives the correct transition with turbulence-centered models for smooth surfaces at low speeds; and predicts experimental data from both laboratory and environmental measurements within the data scatter. The differences between the available laboratory and field data measurements are due to the large differences in the drag coefficient between wind tunnels and oceans. The results also imply that the effect of direct aeration due to bubble entrainment at wave breaking is no more than a 20% increase in the mass transfer for the highest speeds. The theory has importance to mass transfer in both the geophysical and chemical engineering literature.

Duffey, R.B. [Brookhaven National Lab., Upton, NY (United States); Hughes, E.D. [CSA Inc., Idaho Falls, ID (United States)

1995-07-01T23:59:59.000Z

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.


401

Gas mass transfer for stratified flows  

SciTech Connect

We analyzed gas absorption and release in water bodies using existing surface renewal theory. We show a new relation between turbulent momentum and mass transfer from gas to water, including the effects of waves and wave roughness, by evaluating the equilibrium integral turbulent dissipation due to energy transfer to the water from the wind. Using Kolmogoroff turbulence arguments the gas transfer velocity, or mass transfer coefficient, is then naturally and straightforwardly obtained as a non-linear function of the wind speed drag coefficient and the square root of the molecular diffusion coefficient. In dimensionless form, the theory predicts the turbulent Sherwood number to be Sh{sub t} = (2/{radical}{pi})Sc{sup 1/2}, where Sh{sub t} is based on an integral dissipation length scale in the air. The theory confirms the observed nonlinear variation of the mass transfer coefficient as a function of the wind speed; gives the correct transition with turbulence-centered models for smooth surfaces at low speeds; and predicts experimental data from both laboratory and environmental measurements within the data scatter. The differences between the available laboratory and field data measurements are due to the large differences in the drag coefficient between wind tunnels and oceans. The results also imply that the effect of direct aeration due to bubble entrainment at wave breaking is no more than a 20% increase in the mass transfer for the highest speeds. The theory has importance to mass transfer in both the geo-physical and chemical engineering literature.

Duffey, R.B. [Brookhaven National Lab., Upton, NY (United States); Hughes, E.D. [CSA, Inc., Idaho Falls, ID (United States)

1995-06-01T23:59:59.000Z

402

Study of Chemical Changes in Uranium Oxyfluoride Particles Progress Report March - October 2009  

SciTech Connect

Nuclear forensics relies on the analysis of certain sample characteristics to determine the origin and history of a nuclear material. In the specific case of uranium enrichment facilities, it is the release of trace amounts of uranium hexafluoride (UF{sub 6}) gas - used for the enrichment of uranium - that leaves a process-characteristic fingerprint. When UF{sub 6} gas interacts with atmospheric moisture, uranium oxyfluoride particles or particle agglomerates are formed with sizes ranging from several microns down to a few tens of nanometers. These particles are routinely collected by safeguards organizations, such as the International Atomic Energy Agency (IAEA), allowing them to verify whether a facility is compliant with its declarations. Spectrometric analysis of uranium particles from UF{sub 6} hydrolysis has revealed the presence of both particles that contain fluorine, and particles that do not. It is therefore assumed that uranium oxyfluoride is unstable, and decomposes to form uranium oxide. Understanding the rate of fluorine loss in uranium oxyfluoride particles, and the parameters that control it, may therefore contribute to placing boundaries on the particle's exposure time in the environment. Expressly for the purpose of this study, we prepared a set of uranium oxyfluoride particles at the Institute for Reference Materials and Measurements (EU-JRC-IRMM) from a static release of UF{sub 6} in a humid atmosphere. The majority of the samples was stored in controlled temperature, humidity and lighting conditions. Single particles were characterized by a suite of micro-analytical techniques, including NanoSIMS, micro-Raman spectrometry (MRS), scanning (SEM) and transmission (TEM) electron microscopy, energy-dispersive X-ray spectrometry (EDX) and focused ion beam (FIB). The small particle size was found to be the main analytical challenge. The relative amount of fluorine, as well as the particle chemical composition and morphology were determined at different stages in the ageing process, and immediately after preparation. This report summarizes our most recent findings for each of the analytical techniques listed above, and provides an outlook on what remains to be resolved. Additional spectroscopic and mass spectrometric measurements were carried out at Pacific Northwest National Laboratory, but are not included in this summary.

Kips, R; Kristo, M; Hutcheon, I

2009-11-22T23:59:59.000Z

403

Laboratory investigation of chemical and physical properties of soot-containing aerosols  

E-Print Network (OSTI)

Soot particles released from fossil fuel combustion and biomass burning have a large impact on the regional/global climate by altering the atmospheric radiative properties and by serving as cloud condensation nuclei (CCN). However, the exact forcing is affected by the mixing of soot with other aerosol constituents, such as sulfuric acid. In this work, experimental studies have been carried out focusing on three integral parts: (1) heterogeneous uptake of sulfuric acid on soot; (2) hygroscopic growth of H2SO4-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 uptake coefficients of H2SO4 on combustion soot. The results suggest that uptake of H2SO4 takes place efficiently on soot particles, representing an important route to convert hydrophobic soot to hydrophilic aerosols. A tandem differential mobility analyzing (TDMA) system is employed to determine the hygroscopicity of freshly generated soot in the presence of H2SO4 coating. It is found that fresh soot particles are highly hydrophobic, while coating of H2SO4 significantly facilitates water uptake on soot even at sub-saturation relative humidities. The results indicate that aged soot particles in the atmosphere can potentially be an efficient source of CCN. Scattering and extinction coefficient measurements of the soot-H2SO4 mixed particles are conducted using a threewavelength Nephelometer and a multi-path extinction cell. Coating of H2SO4 is found to increase the single scattering albedo (SSA) of soot particles which has impact on the aerosol direct radiative effect. Other laboratory techniques such as transmission electron microscopy (TEM) and Fourier transform infrared spectrometry (FTIR) are utilized to examine the morphology and chemical composition of the soot-H2SO4 particles. This work provides critical information concerning the heterogeneous interaction of soot and sulfuric acid, and how their mixing affects the hygroscopic and optical properties of soot. The results will improve our ability to model and assess the soot direct and indirect forcing and hence enhance our understanding of the impact of anthropogenic activities on the climate.

Zhang, Dan

2003-05-01T23:59:59.000Z

404

Chemical process hazards analysis  

SciTech Connect

The Office of Worker Health and Safety (EH-5) under the Assistant Secretary for the Environment, Safety and Health of the US Department (DOE) has published two handbooks for use by DOE contractors managing facilities and processes covered by the Occupational Safety and Health Administration (OSHA) Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119), herein referred to as the PSM Rule. The PSM Rule contains an integrated set of chemical process safety management elements designed to prevent chemical releases that can lead to catastrophic fires, explosions, or toxic exposures. The purpose of the two handbooks, ``Process Safety Management for Highly Hazardous Chemicals`` and ``Chemical Process Hazards Analysis,`` is to facilitate implementation of the provisions of the PSM Rule within the DOE. The purpose of this handbook ``Chemical Process Hazards Analysis,`` is to facilitate, within the DOE, the performance of chemical process hazards analyses (PrHAs) as required under the PSM Rule. It provides basic information for the performance of PrHAs, and should not be considered a complete resource on PrHA methods. Likewise, to determine if a facility is covered by the PSM rule, the reader should refer to the handbook, ``Process Safety Management for Highly Hazardous Chemicals`` (DOE- HDBK-1101-96). Promulgation of the PSM Rule has heightened the awareness of chemical safety management issues within the DOE. This handbook is intended for use by DOE facilities and processes covered by the PSM rule to facilitate contractor implementation of the PrHA element of the PSM Rule. However, contractors whose facilities and processes not covered by the PSM Rule may also use this handbook as a basis for conducting process hazards analyses as part of their good management practices. This handbook explains the minimum requirements for PrHAs outlined in the PSM Rule. Nowhere have requirements been added beyond what is specifically required by the rule.

NONE

1996-02-01T23:59:59.000Z

405

A backscattering spectrometry device for identifying unknown elements present in a workpiece  

DOE Patents (OSTI)

This invention is comprised of a backscattering spectrometry method and device for identifying and quantifying impurities in a workpiece during processing and manufacturing of that workpiece. While the workpiece is implanted with an ion beam, that same ion beam backscatters resulting from collisions with known atoms and with impurities within the workpiece. Those ions backscatter along a predetermined scattering angle and are filtered using a self-supporting filter to stop the ions with a lower energy because they collided with the known atoms of the workpiece of a smaller mass. Those ions which pass through the filter have a greater energy resulting from impact with impurities having a greater mass than the known atoms of the workpiece. A detector counts the number and measures the energy of the ions which pass through the filter. From the energy determination and knowledge of the scattering angle, a mass calculation determines the identity, and from the number and solid angle of the scattering angle, a relative concentration of the impurity is obtained.

Doyle, B.L.; Knapp, J.A.

1990-12-31T23:59:59.000Z

406

Surface Chemical Dynamics  

NLE Websites -- All DOE Office Websites (Extended Search)

Surface Chemical Dynamics Surface Chemical Dynamics The goal of the Surface Chemical Dynamics Program is to elucidate the underlying physical processes that determine the products (selectivity) and yield (efficiency) of chemical transformations relevant to energy-related chemistry on catalytic and nanostructured surfaces. Achieving this end requires understanding the evolution of the reactant-molecule/surface complex as molecules adsorb, bonds dissociate, surface species diffuse, new bonds form and products desorb. The pathways and time scales of these processes are ultimately determined by a multidimensional potential energy surface that is a function of the geometric and electronic structures of the surface and the reactant, product, intermediate and transition-state molecular and atomic species.

407

Chemicals from coal  

Science Conference Proceedings (OSTI)

This chapter contains sections titled: Chemicals from Coke Oven Distillate; The Fischer-Tropsch Reaction; Coal Hydrogenation; Substitute Natural Gas (SNG); Synthesis Gas Technology; Calcium Carbide; Coal and the Environment; and Notes and References

Harold A. Wittcoff; Bryan G. Reuben; Jeffrey S. Plotkin

2004-12-01T23:59:59.000Z

408

Isotopic Effect on Ion Mobility and Separation of Isotopomers by High-Field Ion Mobility Spectrometry  

SciTech Connect

Since early 1900-s, when vacuum techniques and ion detectors first enabled investigations of gas-phase ions, two approaches to their separation and characterization have emerged - mass spectrometry (MS) and ion mobility spectrometry (IMS).1,2 Though both exploit that distinct charged species move in electric fields differently, MS is performed in vacuum and is based only on the ion mass/charge (m/q) ratio while IMS involves sufficiently dense buffer gases and relies on ion transport properties. The first major discovery enabled by MS was the existence of isotopes by Thomson and Aston,3 and isotopic analyses have since been integral to MS. In particular, the preparative separation of U isotopes using Lawrence’s Calutron was the first industrial application of MS,4 and isotopic labeling is key to MS quantification methods. With IMS, the issue of isotopes was largely ignored as the resolving power (R) was generally too low for their separation. Here, we demonstrate that recently developed high-resolution differential IMS can separate isotopic molecular ions, including nominal isobars with different isotopic content and isotopomers. This capability may enable a new method for isotope separation in a small-scale format at ambient pressure and aid localization of labeled sites in various molecules. Perhaps most importantly, the isotopic shifts depend on the labeled atom position and thus may contain the kind of detailed structural information that is available in solution or solid state using tools such as NMR but has not generally been obtainable for gas-phase ions.

Shvartsburg, Alexandre A.; Clemmer, David E.; Smith, Richard D.

2010-10-01T23:59:59.000Z

409

Chemical Hygiene and Safety Plan  

E-Print Network (OSTI)

towards shop operations. H-1 Chemic_l Hygiene and Safety ,of this section, any chemic:ads per kflop'am of body welshtUNSUPPORTED CHEMIC. -M. VITON NITrlI.E NATI'R.4I. BUTYL

Ricks Editor, R.

2009-01-01T23:59:59.000Z

410

Photon: history, mass, charge  

E-Print Network (OSTI)

The talk consists of three parts. ``History'' briefly describes the emergence and evolution of the concept of photon during the first two decades of the 20th century. ``Mass'' gives a short review of the literature on the upper limit of the photon's mass. ``Charge'' is a critical discussion of the existing interpretation of searches for photon charge. Schemes, in which all photons are charged, are grossly inconsistent. A model with three kinds of photons (positive, negative and neutral) seems at first sight to be more consistent, but turns out to have its own serious problems.

L. B. Okun

2006-02-03T23:59:59.000Z

411

Mass and Heat Recovery  

E-Print Network (OSTI)

In the last few years heat recovery was under spot and in air conditioning fields usually we use heat recovery by different types of heat exchangers. The heat exchanging between the exhaust air from the building with the fresh air to the building (air to air heat exchanger). In my papers I use (water to air heat exchanger) as a heat recovery and I use the water as a mass recovery. The source of mass and heat recovery is the condensate water which we were dispose and connect it to the drain lines.

Hindawai, S. M.

2010-01-01T23:59:59.000Z

412

Ion exchange separation and mass spectrometric analysis of uranium for solutions containing plutonium  

SciTech Connect

An ion exchange technique separates plutonium from uranium using Dowex-1 resin and a methanol--HCl plutonium elutriant. The method is applicable to both trace uranium determination and uranium isotopic distribution analysis by mass spectrometry. Distribution coefficients for plutonium, and elution curves for uranium and plutonium are shown. For uranium analysis the percent relative standard deviation is 0.8 at 120-2400 micrograms uranium per gram plutonium and 5.0 at 5 micrograms uranium per gram plutonium. (auth)

McBride, K.C.

1975-06-01T23:59:59.000Z

413

Argonne Chemical Sciences & Engineering - Facilities - Analytical Chemistry  

NLE Websites -- All DOE Office Websites (Extended Search)

Analytical Chemistry Laboratory Analytical Chemistry Laboratory sullivan ACL manager Vivian Sullivan places a plate for alpha spectrometry into the Alpha Analyst instrument. naik Seema Naik prepares an inorganic sample for analysis on the ICP-Optical Emission Spectrometer. lopykinski Susan Lopykinski prepares a sample for mercury analysis on the cold vapor Atomic Absorption instrument. ICP-Mass Spectrometer Analytical Chemist Yifen Tsai prepares a sample for analysis on the high-resolution ICP-Mass Spectrometer. The Analytical Chemistry Laboratory (ACL) provides a broad range of analytical chemistry support services to the scientific and engineering programs at Argonne National Laboratory and specialized analysis for government, academic, and industrial organizations, including other national laboratories and QA/QC programs and audits.

414

Warm Water Mass Formation  

Science Conference Proceedings (OSTI)

Poleward heat transport by the own implies warm Water mass formation, i.e., the retention by the tropical and subtropical ocean of some of its net radiant heat gain. Under what condition net heat retention becomes comparable to latent heat ...

G. T. Csanady

1984-02-01T23:59:59.000Z

415

Sandia National Labs: PCNSC: Heavy Ion Backscattering Spectrometry  

NLE Websites -- All DOE Office Websites (Extended Search)

Heavy Ion Backscattering Spectrometry (HIBS) Heavy Ion Backscattering Spectrometry (HIBS) IBA Table (HTML) | IBA Table (135KB GIF) | IBA Table (1.2MB PDF) | IBA Table (33MB TIF) | Heavy Ion Backscattering Spectrometry (HIBS) | Virtual Lab Tour (6MB) Description of Technique: HIBS is used to detect ultra-trace levels of heavy impurities on the surface of a Si wafer. HIBS has advantages over TXRF, including: Improved sensitivity for most elements Quantifying composition without standards Measurement on rough surfaces. HIBS is accomplished by focusing a 120 keV beam of C+ions onto a small spot at the wafer's surface. The backscattered ions are collected by a time-of-flight (TOF) detector array with a large solid angle. The flight time of the backscattered C identifies the near-surface impurities and the

416

Electroplating method for producing ultralow-mass fissionable deposits  

DOE Patents (OSTI)

A method for producing ultralow-mass fissionable deposits for nuclear reactor dosimetry is described, including the steps of holding a radioactive parent until the radioactive parent reaches secular equilibrium with a daughter isotope, chemically separating the daughter from the parent, electroplating the daughter on a suitable substrate, and holding the electroplated daughter until the daughter decays to the fissionable deposit.

Ruddy, Francis H. (Monroeville, PA)

1989-01-01T23:59:59.000Z

417

Chemically enhanced oil recovery  

Science Conference Proceedings (OSTI)

Yet when conducted according to present state of the art, chemical flooding (i.e., micellar/polymer flooding, surfactant/polymer flooding, surfactant flooding) can mobilize more residual crude oil than any other method of enhanced oil recovery. It also is one of the most expensive methods of enhanced oil recovery. This contribution will describe some of the technology that comprises the state of the art technology that must be adhered to if a chemical flood is to be successful. Although some of the efforts to reduce cost and other points are discussed, the principle focus is on technical considerations in designing a good chemical flooding system. The term chemical flooding is restricted here to methods of enhanced oil recovery that employs a surfactant, either injected into the oil reservoir or generated in situ, primarily to reduce oil-water interfacial tension. Hence, polymer-water floods for mobility or profile control, steam foams, and carbon dioxide foams are excluded. Some polymer considerations are mentioned because they apply to providing mobility control for chemical flooding systems.

Nelson, R.C.

1989-03-01T23:59:59.000Z

418

Idaho Chemical Processing Plant safety document ICPP hazardous chemical evaluation  

Science Conference Proceedings (OSTI)

This report presents the results of a hazardous chemical evaluation performed for the Idaho Chemical Processing Plant (ICPP). ICPP tracks chemicals on a computerized database, Haz Track, that contains roughly 2000 individual chemicals. The database contains information about each chemical, such as its form (solid, liquid, or gas); quantity, either in weight or volume; and its location. The Haz Track database was used as the primary starting point for the chemical evaluation presented in this report. The chemical data and results presented here are not intended to provide limits, but to provide a starting point for nonradiological hazards analysis.

Harwood, B.J.

1993-01-01T23:59:59.000Z

419

Chemical profiles of switchgrass  

NLE Websites -- All DOE Office Websites (Extended Search)

profiles profiles of switchgrass Zhoujian Hu a,b , Robert Sykes a,c , Mark F. Davis a,c , E. Charles Brummer a,d , Arthur J. Ragauskas a,b,e, * a BioEnergy Science Center, USA b School of Chemistry and Biochemistry, Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA 30332, USA c National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401, USA d Institute for Plant Breeding, Genetics, and Genomics, Department of Crop and Soil Sciences, University of Georgia, Athens, GA 30602, USA e Forest Products and Chemical Engineering Department, Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden a r t i c l e i n f o Article history: Received 15 April 2009 Received in revised form 10 December 2009 Accepted 10 December 2009 Available online 13 January 2010 Keywords: Switchgrass Morphological components Chemical

420

Carbon Emissions: Chemicals Industry  

U.S. Energy Information Administration (EIA) Indexed Site

Chemicals Industry Chemicals Industry Carbon Emissions in the Chemicals Industry The Industry at a Glance, 1994 (SIC Code: 28) Total Energy-Related Emissions: 78.3 million metric tons of carbon (MMTC) -- Pct. of All Manufacturers: 21.1% -- Nonfuel Emissions: 12.0 MMTC Total First Use of Energy: 5,328 trillion Btu -- Pct. of All Manufacturers: 24.6% Energy Sources Used As Feedstocks: 2,297 trillion Btu -- LPG: 1,365 trillion Btu -- Natural Gas: 674 trillion Btu Carbon Intensity: 14.70 MMTC per quadrillion Btu Energy Information Administration, "1994 Manufacturing Energy Consumption Survey" and Emissions of Greenhouse Gases in the United States 1998 Energy-Related Carbon Emissions, 1994 Source of Carbon Carbon Emissions (million metric tons) All Energy Sources 78.3 Natural Gas 32.1

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

Chemical Cleaning Program Review  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Chemical Cleaning Chemical Cleaning Program Review Neil Davis Deputy Program Manager Waste Removal & Tank Closure July 29, 2009 SRR-STI-2009-00464 2 Contents Regulatory drivers Process overview Preliminary results Lessons learned Path forward 3 Regulatory Drivers The Federal Facilities Agreement establishes milestones for the removal of bulk waste and closure of each non-compliant tank Per the Dispute Resolution: - "DOE shall complete operational closure of Tanks 19 and 18 by 12/31/2012" - "DOE shall complete operational closure of 4 tanks by 9/30/2015" SRR intention to close 4 tanks by 9/30/2010, or as soon as possible Tanks 5 & 6 will be 2 of the 4 tanks 4 Tank Closure Process Bulk Waste Removal Mechanical Heel Removal Chemical Cleaning Annulus

422

Chemical Label Information  

NLE Websites -- All DOE Office Websites (Extended Search)

Chemical Label Information Chemical Label Information Chemical Name CAS No. NFPA 704 Label Data Hazard Information Health Fire Reactivity Other acetone 67641 1 3 0 Eye, skin and mucous membrane irritatiion. Central nervous system depression. chloroform 67663 2 0 0 CAR [1] and TERAT [2] Liver and kidney disorders. Eye and skin irritation. Central nervous system depression. Cardiac arrythmia. ethanol 64175 0 3 0 Skin and eye irritation. ethyl alcohol 64175 0 3 0 Skin and eye irritation. hydrofluoric acid 7664393 4 0 0 Acute [3] - Skin contact can lead to bone damage. Skin, eye and mucous membrane irritation. hydrogen peroxide (35 to 52%) 7722841 2 0 1 OX Very irritating to the skin, eye and respiratory tract. hydrogen peroxide (> 52%) 7722841 2 0 3 OX Extremely irritating to the skin, eye and respiratory tract.

423

Chemical Storage-Overview  

NLE Websites -- All DOE Office Websites (Extended Search)

Storage - Storage - Overview Ali T-Raissi, FSEC Hydrogen Storage Workshop Argonne National Laboratory, Argonne, Illinois August 14-15, 2002 Hydrogen Fuel - Attributes * H 2 +½ O 2 → H 2 O (1.23 V) * High gravimetric energy density: 27.1 Ah/g, based on LHV of 119.93 kJ/g * 1 wt % = 189.6 Wh/kg (0.7 V; i.e. η FC = 57%) * Li ion cells: 130-150 Wh/kg Chemical Hydrides - Definition * They are considered secondary storage methods in which the storage medium is expended - primary storage methods include reversible systems (e.g. MHs & C-nanostructures), GH 2 & LH 2 storage Chemical Hydrides - Definition (cont.) * The usual chemical hydride system is reaction of a reactant containing H in the "-1" oxidation state (hydride) with a reactant containing H in the "+1" oxidation

424

Method for calibrating mass spectrometers  

DOE Patents (OSTI)

A method whereby a mass spectra generated by a mass spectrometer is calibrated by shifting the parameters used by the spectrometer to assign masses to the spectra in a manner which reconciles the signal of ions within the spectra having equal mass but differing charge states, or by reconciling ions having known differences in mass to relative values consistent with those known differences. In this manner, the mass spectrometer is calibrated without the need for standards while allowing the generation of a highly accurate mass spectra by the instrument.

Anderson, Gordon A [Benton City, WA; Brands, Michael D [Richland, WA; Bruce, James E [Schwenksville, PA; Pasa-Tolic, Ljiljana [Richland, WA; Smith, Richard D [Richland, WA

2002-12-24T23:59:59.000Z

425

Physical and Chemical Applications  

NLE Websites -- All DOE Office Websites (Extended Search)

data image data image Physical and Chemical Applications Research in this area includes: Chemical analysis (femtosecond laser ablation). Advanced sensors (laser ultrasonics). Advanced materials and nanotechnology for clean energy- hydrogen storage, nanostructured organic light-emitting diodes, nanowires, and nanoparticles). Photons to fuels (biosynthetic pathways for generating hydrocarbon biofuels in photosynthetic organisms). Advanced Sensor Development Sensor-based control of industrial processes can help companies: Decrease production costs; Reduce waste of raw materials on manufacturing lines; Lower manufacturing downtime from equipment maintenance; Increase the energy efficiency of manufacturing processes; Detect equipment failure early, before it becomes a major liability;

426

Twisted mass finite volume effects  

SciTech Connect

We calculate finite-volume effects on the pion masses and decay constant in twisted mass lattice QCD at finite lattice spacing. We show that the lighter neutral pion in twisted mass lattice QCD gives rise to finite-volume effects that are exponentially enhanced when compared to those arising from the heavier charged pions. We demonstrate that the recent two flavor twisted mass lattice data can be better fitted when twisted mass effects in finite-volume corrections are taken into account.

Colangelo, Gilberto; Wenger, Urs; Wu, Jackson M. S. [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of Bern, Sidlerstrasse 5, 3012 Bern (Switzerland)

2010-08-01T23:59:59.000Z

427

Effect of $U_A(1)$ Breaking on Chiral Phase Structure and Pion Superfluidity at Finite Isospin Chemical Potential  

E-Print Network (OSTI)

We investigate the isospin chemical potential effect in the frame of SU(2) Nambu-Jona-Lasinio model. When the isospin chemical potential is less than the vacuum pion mass, the phase structure with two chiral phase transition lines does not happen due to $U_A(1)$ breaking of QCD. When the isospin chemical potential is larger than the vacuum pion mass, the ground state of the system is a Bose-Einstein condensate of charged pions.

Lianyi He; Meng Jin; Pengfei Zhuang

2005-03-24T23:59:59.000Z

428

Chemical potential and the gap equation  

E-Print Network (OSTI)

In general the kernel of QCD's gap equation possesses a domain of analyticity upon which the equation's solution at nonzero chemical potential is simply obtained from the in-vacuum result through analytic continuation. On this domain the single-quark number- and scalar-density distribution functions are mu-independent. This is illustrated via two models for the gap equation's kernel. The models are alike in concentrating support in the infrared. They differ in the form of the vertex but qualitatively the results are largely insensitive to the Ansatz. In vacuum both models realise chiral symmetry in the Nambu-Goldstone mode and in the chiral limit, with increasing chemical potential, exhibit a first-order chiral symmetry restoring transition at mu~M(0), where M(p^2) is the dressed-quark mass function. There is evidence to suggest that any associated deconfinement transition is coincident and also of first-order.

Huan Chen; Wei Yuan; Lei Chang; Yu-Xin Liu; Thomas Klahn; Craig D. Roberts

2008-07-17T23:59:59.000Z

429

Chemical Logging | Open Energy Information  

Open Energy Info (EERE)

Chemical Logging Chemical Logging Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Chemical Logging Details Activities (1) Areas (1) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Log Techniques Parent Exploration Technique: Well Log Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Presence and geochemical composition of fluid producing zones Thermal: Calcium-alkalinity ratios versus depth assist in defining warm and hot water aquifers Dictionary.png Chemical Logging: Chemical logging produces a chemical profile of the formation fluid within a well based on the measurement of changes in the chemical composition of the drilling fluid during drilling operations.

430

Mass Market Demand Response  

NLE Websites -- All DOE Office Websites (Extended Search)

Mass Market Demand Response Mass Market Demand Response Speaker(s): Karen Herter Date: July 24, 2002 - 12:00pm Location: Bldg. 90 Demand response programs are often quickly and poorly crafted in reaction to an energy crisis and disappear once the crisis subsides, ensuring that the electricity system will be unprepared when the next crisis hits. In this paper, we propose to eliminate the event-driven nature of demand response programs by considering demand responsiveness a component of the utility obligation to serve. As such, demand response can be required as a condition of service, and the offering of demand response rates becomes a requirement of utilities as an element of customer service. Using this foundation, we explore the costs and benefits of a smart thermostat-based demand response system capable of two types of programs: (1) a mandatory,

431

On the steady states of weakly reversible chemical reaction networks  

E-Print Network (OSTI)

A natural condition on the structure of the underlying chemical reaction network, namely weak reversibility, is shown to guarantee the existence of an equilibrium (steady state) in each positive stoichiometric compatibility class for the associated mass-action system. Furthermore, an index formula is given for the set of equilibria in a given stoichiometric compatibility class.

Deng, Jian; Feinberg, Martin; Nachman, Adrian

2011-01-01T23:59:59.000Z

432

Chemical Conversion Coating  

Science Conference Proceedings (OSTI)

Table 16   Applications of aluminum using chemical conversion coatings...doors 6063 Acrylic paint (b) Cans 3004 Sanitary lacquer Fencing 6061 None applied Chromate conversion coatings Aircraft fuselage skins 7075 clad with 7072 Zinc chromate primer Electronic chassis 6061-T4 None applied Cast missile bulkhead 356-T6 None applied Screen 5056 clad with 6253 Clear varnish...

433

Strange and charm meson masses from twisted mass lattice QCD  

E-Print Network (OSTI)

We present first results of a 2+1+1 flavor twisted mass lattice QCD computation of strange and charm meson masses. We focus on D and D_s mesons with spin J = 0,1 and parity P = -,+.

Martin Kalinowski; Marc Wagner

2012-12-03T23:59:59.000Z

434

Mass algal culture system  

DOE Patents (OSTI)

An apparatus and process for the culture of algae in a liquid medium is disclosed. The medium circulates through an open trough and is exposed to an atmosphere which is temperature regulated. The nutrient content of the liquid medium is regulated to control the chemical composition growth and reproduction characteristics of the cultured algae. Before it is allowed to strike the medium, sunlight is passed through a filter to remove wavelengths which are not photosynthetically active. Heat energy can be recovered from the filter.

Raymond, Lawrence P. (Richland, WA)

1981-01-01T23:59:59.000Z

435

Mass algal culture system  

DOE Patents (OSTI)

An apparatus and process for the culture of algae in a liquid medium is disclosed. The medium circulates through an open trough and is exposed to an atmosphere which is temperature regulated. The nutrient content of the liquid medium is regulated to control the chemical composition growth and reproduction characteristics of the cultured algae. Before it is allowed to strike the medium, sunlight is passed through a filter to remove wavelengths which are not photosynthetically active. Heat energy can be recovered from the filter.

Raymond, Lawrence P. (Richland, WA)

1982-01-01T23:59:59.000Z

436

Practical considerations in realizing a magnetic centrifugal mass filter Renaud Gueroult and Nathaniel J. Fisch  

E-Print Network (OSTI)

centrifugal mass filter concept represents a variation on the plasma centrifuge, with applications of chemical separation. In par- ticular, in the Ohkawa mass filter, particles are separated relying kinetic energy should be such that heavy ions cannot overcome the centrifu- gal potential well

437

CSD: Research Programs: Chemical Physics  

NLE Websites -- All DOE Office Websites (Extended Search)

CSD: Research: Chemical Physics CSD: Research Programs: Chemical Physics CSD: Research: Chemical Physics CSD: Research Programs: Chemical Physics LBL Logo A-Z CSD Research Highlights CSD Directory Chemical Sciences Division A-Z Index Phone Book Search Berkeley Lab INTRODUCTION TO CSD NATIONAL FACILITIES & CENTERS RESEARCH PROGRAMS Atomic, Molecular & Optical Sciences Catalytic Science Chemical Physics The Glenn T. Seaborg Center (GTSC) STUDENT & POSTDOCTORAL OPPORTUNITIES NEWS & EVENTS CSD CONTACTS LBNL HOME Privacy & Security Notice DOE UC Berkeley CSD > Research Programs > Chemical Physics The Chemical Physics Program of the Chemical Science Division of LBNL is concerned with the development of both experimental and theoretical methodologies for studying molecular structure and dynamical processes at the most fundamental level, and with the application of these to specific

438

Work Practices for Chemical Fumehoods  

NLE Websites -- All DOE Office Websites (Extended Search)

Practices for Chemical Fumehoods Practices for Chemical Fumehoods (Reviewed May 16, 2011) Always use a chemical fumehood when working with toxic and/or volatile chemicals, not on an open bench. Chemical fumehoods are designed to provide protection for the user from chemical and radiological contaminants. However, they do not absolutely eliminate exposure, even under ideal conditions. Careless work practices can result in considerable exposure to users who may believe they are protected. To optimize the performance of the chemical hood, adhere to the following work practices: 1. Ensure that your chemical hood has a current inspection sticker (dated within the last year). The face velocity should be between 80 and 120 linear feet per minute (lfpm). 2. Verify that the chemical hood is drawing air.

439

MassMass transfer andtransfer and separation technologyseparation technology  

E-Print Network (OSTI)

Driving force Apparatus Heat exchange Energy T Heat exchanger Gas absorption Mass G L c y-y* Packed towerGas absorption Mass G L c, y-y* Packed tower, or tray column Gas desorption Mass L G c, y*-y Packed tower tower, or tray column and B from a mix Vaporisation cooling Energy, water h (enthalpy) Spray tower

Zevenhoven, Ron

440

ROBOTIC SYSTEMS for DEPLOYING SENSORS to DETECT CONTRABAND in CARGO  

E-Print Network (OSTI)

in this respect from sniffing explosives on the persons of terrorists passing through airports: explosives solvent detection, quadrupole mass spectrometry chemical taggant detection tandem/hybrid techniques

Siegel, Mel

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

ROBOTIC SYSTEMS for DEPLOYING SENSORS to DETECT CONTRABAND in CARGO  

E-Print Network (OSTI)

in this respect from sniffing explosives on the persons of terrorists passing through airports: explosives detection, quadrupole mass spectrometry chemical taggant detection tandem/hybrid techniques biosensors eddy

Siegel, Mel

442

TABLE OF CONTENTS I. PHYSICAL & CHEMICAL ...  

Science Conference Proceedings (OSTI)

Page 1. Chemical Science and Technology Laboratory Page 1 Technical Activities Report Physical & Chemical Properties Division ...

2001-06-12T23:59:59.000Z

443

Chemical Engineering & Processing Humidity Information at ...  

Science Conference Proceedings (OSTI)

NIST Home > Chemical Engineering & Processing Humidity Information at NIST. Chemical Engineering & Processing Humidity Information at NIST. ...

2010-09-24T23:59:59.000Z

444

"Gravitational mass" of information?  

E-Print Network (OSTI)

We hypothesize possible new types of forces that would be the result of new types of interactions, static and a slow transient, between objects with related information contents (pattern). Such mechanism could make material composition dependence claimed by Fishbach, et al in Eotvos type experiments plausible. We carried out experiments by using a high-resolution scale with the following memories: USB-2 flash drives (1-16GB), DVD and CD disks to determine if such an interaction exist/detectable with a scale resolution of 10 microgram with these test objects. We applied zero information, white noise and 1/f noise type data. Writing or deleting the information in any of these devices causes peculiar negative weight transients, up to milligrams (mass fraction around 10^-5), which is followed by various types of relaxation processes. These relaxations have significantly different dynamics compared to transients observed during cooling after stationary external heating. Interestingly, a USB-1 MP3 player has also developed comparable transient mass loss during playing music. A classical interpretation of the negative weight transients could be absorbed water in hygroscopic components however comparison of relaxation time constants with air humidity data does not support an obvious explanation. Another classical interpretation with certain contribution is the lifting Bernoulli force caused by the circulation due to convection of the warm air. However, in this case all observed time constants with a device should have been the same unless some hidden parameter causes the observed variations. Further studies are warranted to clarify if there is indeed a new force, which is showing up as negative mass at weight measurement when high-density structural information is changed or read out (measured).

Laszlo B. Kish

2007-11-08T23:59:59.000Z

445

MASS SPECTROMETER LEAK  

DOE Patents (OSTI)

An improved valve is described for precisely regulating the flow of a sample fluid to be analyzed, such as in a mass spectrometer, where a gas sample is allowed to "leak" into an evacuated region at a very low, controlled rate. The flow regulating valve controls minute flow of gases by allowing the gas to diffuse between two mating surfaces. The structure of the valve is such as to prevent the corrosive feed gas from contacting the bellows which is employed in the operation of the valve, thus preventing deterioration of the bellows.

Shields, W.R.

1960-10-18T23:59:59.000Z

446

HIGEE Mass Transfer  

E-Print Network (OSTI)

Distillation, absorption, and gas stripping have traditionally been performed in tall columns utilizing trays or packing. Columns perform satisfactorily, but have characteristics which may be disadvantages in some applications: Large size, particularly height; high weight; high cost of installation; difficulty in modularization; foaming for certain systems; must be vertical, especially for trayed towers; large liquid inventory; difficulty in modifying column internals once installed; start up time to reach steady state conditions in excessive. Many of these disadvantages can be overcome by use of HIGEE, an innovative vapor-liquid mass transfer system which utilizes a rotating bed of packing to achieve high efficiency separations, and consequent reduction in size and weight.

Mohr, R. J.; Fowler, R.

1986-06-01T23:59:59.000Z

447

Heat and mass exchanger  

Science Conference Proceedings (OSTI)

A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)

2011-06-28T23:59:59.000Z

448

Chemical Sciences Division: Directory  

NLE Websites -- All DOE Office Websites (Extended Search)

INTRODUCTION INTRODUCTION TO CSD NATIONAL FACILITIES & CENTERS RESEARCH STUDENT & POSTDOCTORAL OPPORTUNITIES NEWS & EVENTS CSD CONTACTS LBNL HOME Privacy & Security Notice DOE UC Berkeley CSD Directory A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A Rebecca Abergel CSD Project Scientist; The Glenn T. Seaborg Center. Musahid Ahmed CSD Staff Scientist, Chemical Physics Program/Chemical Dynamics Beamline Publications Richard A. Andersen Professor of Chemistry, UC Berkeley; CSD Senior Faculty Scientist, The Glenn T. Seaborg Center Publications John Arnold Professor of Chemistry, UC Berkeley; CSD Faculty Scientist, Catalytic Science Program Publications B Ali Belkacem CSD Deputy and Senior Staff Scientist; Atomic, Molecular and Optical Sciences Program Leader

449

Resistance to Chemicals  

Science Conference Proceedings (OSTI)

Table 14   Corrosion of lead in chemical process fluids...� � 76.2 3 Tallow � � 304.8 12 Olive � � 76.2 3 Cod liver � � 152.4 6 Neatsfoot � � 279.4 11 Fish � � 279.4 11 Vegetable � � 584.2 23 Peanut � � 457.2 18 Sulfonation with

450

A reactive BGK-type model: influence of elastic collisions and chemical interactions  

E-Print Network (OSTI)

, momentum and total energy (kinetic plus internal chemical bond energy). Moreover the H theorem holds true is typical in Hydrogen combustion applications. #12;KINETIC MODEL With reference to Eq. (2), the microscopic reproduces the laws of chemical kinetics. #12;Conservation laws. Conservation of mass, momentum and total

Ceragioli, Francesca

451

Chemical composition of melanin  

NLE Websites -- All DOE Office Websites (Extended Search)

Chemical composition of melanin Chemical composition of melanin Name: Peggy M Siemers Status: N/A Age: N/A Location: N/A Country: N/A Date: N/A Question: What is the chemical composition of Melanin by specific amino acids, or the DNA code for melanin? Replies: This is a good question! The answer is somewhat complex and I'm sure I don't have all the details but here goes... First, there is not a specific DNA code for melanin because like many biomolecules, it is not the result of a single gene product. People that are deficient in melanin are oculo/dermal albinos and I believe there have been seven different types of mutations. These different mutations reflect the multiple steps required to produce melanin. The original building block for melanin is tyrosine, one of the amino acids. This amino acid is modified by enzymes to produce the building block (monomer) for melanin synthesis by a process called polymerization that is also controlled by an enzyme. The polymers ,I believe, can attain diff3erent lengths and they can also form aggregates of different sizes alone and in combination with other molecules such as proteins. This is in part responsible for differences in coloration seen within and between individuals. NEWTON RULES

452

Determining the neutrino mass hierarchy  

Science Conference Proceedings (OSTI)

In this proceedings I review the physics that future experiments will use to determine the neutrino mass hierarchy.

Parke, Stephen J.; /Fermilab

2006-07-01T23:59:59.000Z

453

Real-time, in situ film thickness metrology in a 10 Torr W chemical vapor deposition process using an acoustic sensor  

E-Print Network (OSTI)

analysis to establish a sensor model with an accuracy better than 1%. This was achieved in a 10 Torr W CVD achieving film thickness metrology with a 2% error using mass spectrometry or residual gas analysis scale Ulvac ERA 1000 W CVD cluster tool which is outfitted with water- cooled walls. The WF6 precursor

Rubloff, Gary W.

454

Chemical nature of the passivation layer depending on the oxidizing agent in Gd2O3/GeO2/Ge stacks grown by molecular beam deposition  

Science Conference Proceedings (OSTI)

In Ge-based metal oxide semiconductor technology, the insertion of a passivation layer seems to be crucial in unpinning the Fermi level at the interface and in reducing the amount of interface defects. GeO"2 was obtained by atomic oxygen (AO), molecular ... Keywords: Gadolinium oxide, Germanium, Molecular beam deposition, Passivation layer, Time-of-flight secondary ion mass spectrometry

A. Lamperti; S. Baldovino; A. Molle; M. Fanciulli

2011-04-01T23:59:59.000Z

455

Chemical engineers design, control and optimize large-scale chemical,  

E-Print Network (OSTI)

Chemical Process and Plant Design (3, Sp) Applications of unit opera- tions, thermodynamics, kinetics variables and random functions. Application to chemical engineering problems, including process design concepts of chemical kinetics and chemi- cal reactor design. Prerequisite: MATH 245. coUrSeS of in

Wang, Hai