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Note: This page contains sample records for the topic "beam mass spectrometry" 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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1

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

SciTech Connect (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

2

Apparatus and methods for continuous beam fourier transform mass spectrometry  

DOE Patents [OSTI]

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

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

2002-01-01T23:59:59.000Z

3

Gas Chromatography -Mass Spectrometry  

E-Print Network [OSTI]

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

Nizkorodov, Sergey

4

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

SciTech Connect (OSTI)

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

5

THE EARLY DAYS OF ACCELERATOR MASS SPECTROMETRY  

E-Print Network [OSTI]

reported work in high energy mass spectrometry-two in 1938,importance of high energy mass spectrometry was demonstrated

Alvarez, L.W.

2010-01-01T23:59:59.000Z

6

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

7

Secondary ion mass spectrometry (SIMS)! Seminar 4 (UN)!  

E-Print Network [OSTI]

for compositional analysis of solid surfaces and thin films. When a surface is bombarded by high energy beam! ! Secondary ion mass spectrometry (SIMS)! Seminar 4 (UN)! ! ! ! ! ! ! ! ! Author: Nina Kovacic! ___________________________________________________________________________! ABSTRACT! ! Secondary ion mass spectrometry (SIMS) is an analytical experimental technique, used

Â?umer, Slobodan

8

Effusive molecular beam-sampled Knudsen flow reactor coupled to vacuum ultraviolet single photon ionization mass spectrometry using an external free radical source  

SciTech Connect (OSTI)

A new apparatus using vacuum ultraviolet single photon ionization mass spectrometry (VUV SPIMS) of an effusive molecular beam emanating from a Knudsen flow reactor is described. It was designed to study free radical-molecule kinetics over a significant temperature range (300–630 K). Its salient features are: (1) external free radical source, (2) counterpropagating molecular beam and diffuse VUV photon beam meeting in a crossed-beam ion source of a quadrupole mass spectrometer with perpendicular ion extraction, (3) analog detection of the photocurrent of the free radical molecular cation, and (4) possibility of detecting both free radicals and closed shell species in the same apparatus and under identical reaction conditions owing to the presence of photoelectrons generated by the photoelectric effect of the used VUV-photons. The measured thermal molecular beam-to-background ratio was 6.35 ± 0.39 for Ar and 10.86 ± 1.59 for i-C{sub 4}H{sub 10} at 300 K, a factor of 2.52 and 1.50 smaller, respectively, than predicted from basic gas-dynamic considerations. Operating parameters as well as the performance of key elements of the instrument are presented and discussed. Coupled to an external free radical source a steady-state specific exit flow of 1.6 × 10{sup 11} and 5.0 × 10{sup 11} molecule s{sup ?1} cm{sup ?3} of C{sub 2}H{sub 5}{sup •} (ethyl) and t-C{sub 4}H{sub 9}{sup •} (t-butyl) free radicals have been detected using VUV SPIMS at their molecular ion m/z 29 and 57, respectively, at 300 K.

Leplat, N.; Rossi, M. J. [Laboratory of Atmospheric Chemistry (LAC), Paul Scherrer Institute (PSI), CH-5232 Villigen PSI (Switzerland)] [Laboratory of Atmospheric Chemistry (LAC), Paul Scherrer Institute (PSI), CH-5232 Villigen PSI (Switzerland)

2013-11-15T23:59:59.000Z

9

Symposium on accelerator mass spectrometry  

SciTech Connect (OSTI)

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

None

1981-01-01T23:59:59.000Z

10

Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

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

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

2014-06-13T23:59:59.000Z

11

Mass Spectrometry | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region serviceMissionreal-time informationScience &MapsMarketsMass

12

accurate mass spectrometry: Topics by E-print Network  

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

Positive Negative *) Atomic composition Graham, Nick 2 FOCUS: TOP-DOWN MASS SPECTROMETRY Collective Mass Spectrometry Approaches Biology and Medicine Websites Summary:...

13

Atmospheric Solids Analysis Probe Mass Spectrometry: A New Approach...  

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

Atmospheric Solids Analysis Probe Mass Spectrometry: A New Approach for Airborne Particle Analysis. Atmospheric Solids Analysis Probe Mass Spectrometry: A New Approach for Airborne...

14

New Mass Spectrometry Techniques for Studying Physical Chemistry...  

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

Mass Spectrometry Techniques for Studying Physical Chemistry of Atmospheric Heterogeneous Processes. New Mass Spectrometry Techniques for Studying Physical Chemistry of Atmospheric...

15

Methods for recalibration of mass spectrometry data  

DOE Patents [OSTI]

Disclosed are methods for recalibrating mass spectrometry data that provide improvement in both mass accuracy and precision by adjusting for experimental variance in parameters that have a substantial impact on mass measurement accuracy. Optimal coefficients are determined using correlated pairs of mass values compiled by matching sets of measured and putative mass values that minimize overall effective mass error and mass error spread. Coefficients are subsequently used to correct mass values for peaks detected in the measured dataset, providing recalibration thereof. Sub-ppm mass measurement accuracy has been demonstrated on a complex fungal proteome after recalibration, providing improved confidence for peptide identifications.

Tolmachev, Aleksey V. (Richland, WA); Smith, Richard D. (Richland, WA)

2009-03-03T23:59:59.000Z

16

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

SciTech Connect (OSTI)

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

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

2011-10-12T23:59:59.000Z

17

High performance ˛?˛Cf plasma desorption mass spectrometry  

E-Print Network [OSTI]

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

McIntire, Thomas Shane

1991-01-01T23:59:59.000Z

18

accuracy mass spectrometry: Topics by E-print Network  

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

Milos 2 High Mass Accuracy and High Mass Resolving Power FT-ICR Secondary Ion Mass Spectrometry for Biological Tissue Imaging CERN Preprints Summary: Biological tissue imaging by...

19

Optimization Of A Mass Spectrometry Process  

SciTech Connect (OSTI)

In this paper we present and discuss a system developed in order to optimize the mass spectrometry process of an ion implanter. The system uses a PC to control and display the mass spectrum. The operator interacts with the I/O board, that interfaces with the computer and the ion implanter by a LabVIEW code. Experimental results are shown and the capabilities of the system are discussed.

Lopes, Jose [Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emidio Navarro, 1, 1959-007 Lisbon (Portugal); Instituto Superior Tecnico, Av. Rovisco Pais, 1, 1049-001 Lisbon (Portugal); Instituto Tecnologico e Nuclear, E.N. 10, Sacavem 2686-953 (Portugal); Centro de Fisica Nuclear da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Alegria, F. Correa [Instituto Superior Tecnico, Av. Rovisco Pais, 1, 1049-001 Lisbon (Portugal); Instituto de Telecomunicacoes, Av. Rovisco Pais, 1, 1049-001 Lisbon (Portugal); Redondo, Luis [Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emidio Navarro, 1, 1959-007 Lisbon (Portugal); Centro de Fisica Nuclear da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Barradas, N. P.; Alves, E. [Instituto Tecnologico e Nuclear, E.N. 10, Sacavem 2686-953 (Portugal); Centro de Fisica Nuclear da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Rocha, Jorge [Instituto Tecnologico e Nuclear, E.N. 10, Sacavem 2686-953 (Portugal)

2011-06-01T23:59:59.000Z

20

applying mass spectrometry: Topics by E-print Network  

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

*) Atomic composition Graham, Nick 4 Analytical Performance of Accelerator Mass Spectrometry and Liquid Scintillation Counting for Biotechnology Websites Summary: Analytical...

Note: This page contains sample records for the topic "beam mass spectrometry" 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

ablation mass spectrometry: Topics by E-print Network  

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

and laser ablation electrospray ionization mass Chemistry Websites Summary: -mass spectrometry (DESI-MS) and laser ablation electrospray ionization-MS (LAESI-MS) were used to...

22

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

23

Electrospray Ionization Mass Spectrometry of hexanitrohexaazaisowurtzitane (CL-20)  

SciTech Connect (OSTI)

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

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

2007-09-03T23:59:59.000Z

24

ambient mass spectrometry: Topics by E-print Network  

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

and Applications of Liquid Sample Desorption Electrospray Ionization Mass Spectrometry (DESI-MS). Open Access Theses and Dissertations Summary: ?? This dissertation...

25

analytical mass spectrometry: Topics by E-print Network  

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

analytical methods for solving a variety of molecular structure problems. Among high. Extension of mass spectrometry to the analysis of high molecular weight materials,...

26

aerosol mass spectrometry: Topics by E-print Network  

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

analysis of aerosol organic nitrates with electron ionization high-resolution mass spectrometry MIT - DSpace Summary: Four hydroxynitrates (R(OH)R'ONO2) representative of...

27

High-Resolution Electrospray Ionization Mass Spectrometry Analysis...  

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

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

28

Multinozzle Emitter Arrays for Nanoelectrospray Mass Spectrometry  

SciTech Connect (OSTI)

Mass spectrometry (MS) is the enabling technology for proteomics and metabolomics. However, dramatic improvements in both sensitivity and throughput are still required to achieve routine MS-based single cell proteomics and metabolomics. Here, we report the silicon-based monolithic multinozzle emitter array (MEA), and demonstrate its proof-of-principle applications in high-sensitivity and high-throughput nanoelectrospray mass spectrometry. Our MEA consists of 96 identical 10-nozzle emitters in a circular array on a 3-inch silicon chip. The geometry and configuration of the emitters, the dimension and number of the nozzles, and the micropillar arrays embedded in the main channel, can be systematically and precisely controlled during the microfabrication process. Combining electrostatic simulation and experimental testing, we demonstrated that sharpened-end geometry at the stem of the individual multinozzle emitter significantly enhanced the electric fields at its protruding nozzle tips, enabling sequential nanoelectrospray for the high-density emitter array. We showed that electrospray current of the multinozzle emitter at a given total flow rate was approximately proportional to the square root of the number of its spraying-nozzles, suggesting the capability of high MS sensitivity for multinozzle emitters. Using a conventional Z-spray mass spectrometer, we demonstrated reproducible MS detection of peptides and proteins for serial MEA emitters, achieving sensitivity and stability comparable to the commercial capillary emitters. Our robust silicon-based MEA chip opens up the possibility of a fully-integrated microfluidic system for ultrahigh-sensitivity and ultrahigh-throughput proteomics and metabolomics.

Mao, Pan; Wang, Hung-Ta; Yang, Peidong; Wang, Daojing

2011-06-16T23:59:59.000Z

29

RAPID COMMUNICATIONS IN MASS SPECTROMETRY Rapid Commun. Mass Spectrom. 2004; 18: 27062712  

E-Print Network [OSTI]

mass spectrometry.7,8 The internal energy that ions acquire in the MALDI process or via colli- sional of high quality. Tandem mass spectrometry utilizing photodissociation (PD) with ultraviolet (UV) radiation be a viable alternative to CAD for tandem mass spectrometry of large molecules because the energy requirement

Kim, Myung Soo

30

Future Directions of Structural Mass Spectrometry using Hydroxyl Radical Footprinting  

SciTech Connect (OSTI)

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

J Kiselar; M Chance

2011-12-31T23:59:59.000Z

31

Digital microfluidic sample preparation for biological mass spectrometry   

E-Print Network [OSTI]

The use of mass spectrometry in the biosciences has undergone huge growth in re- cent years due to sustained effort in the development of new ionisation techniques, more powerful mass analysers and better bioinformatic ...

Stokes, Adam A.

2011-06-27T23:59:59.000Z

32

Single Cell Analysis Using Microfluidics Coupled to Ultrasensitive Mass Spectrometry  

E-Print Network [OSTI]

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

33

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

34

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

35

Analytical Performance of Accelerator Mass Spectrometry and Liquid Scintillation Counting for  

E-Print Network [OSTI]

Analytical Performance of Accelerator Mass Spectrometry and Liquid Scintillation Counting for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California of California, San Francisco, California 94143 Accelerator mass spectrometry (AMS) has been applied

Hammock, Bruce D.

36

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

SciTech Connect (OSTI)

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

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

1993-01-01T23:59:59.000Z

37

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

SciTech Connect (OSTI)

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

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

2000-05-01T23:59:59.000Z

38

Mass Spectrometry-based Methods for Phosphorylation Site Mapping of  

E-Print Network [OSTI]

Mass Spectrometry-based Methods for Phosphorylation Site Mapping of Hyperphosphorylated Proteins spectrometry-based approach. No one approach was able to identify all phosphopeptides in the tryptic digests and detected by scintillation counting or autoradiography. The HPLC fraction or excised TLC spot is subjected

Shou, Wenying

39

Toward Plasma Proteome Profiling with Ion Mobility-Mass Spectrometry  

E-Print Network [OSTI]

Toward Plasma Proteome Profiling with Ion Mobility-Mass Spectrometry Stephen J. Valentine, Manolo D) analysis of a plasma digest sample where abundant proteins have not been removed. Protein database searches- for comparative plasma profiling studies. Keywords: ion mobility spectrometry · proteome profiling

Clemmer, David E.

40

Accelerator mass spectrometry: from nuclear physics to dating  

SciTech Connect (OSTI)

The discussion reviews the use of accelerators originally intended for nuclear physics to do high resolution mass spectrometry for the purpose of isotope dating and age estimation of materials. (GHT)

Kutschera, W.

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam mass spectrometry" 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

accelerator mass spectrometry: Topics by E-print Network  

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

Bousfield, George R. 2004-05-01 25 High performance ?Cf plasma desorption mass spectrometry Texas A&M University - TxSpace Summary: Track and the Dissemination of Energy. . ....

42

Tools for investigating cellular signaling networks by mass spectrometry  

E-Print Network [OSTI]

Mass spectrometry has become the tool of choice for proteomics. Its unrivaled coverage and reproducibility has positioned it head and shoulders above competing techniques for analyzing protein expression post-translational ...

Curran, Timothy Gordon

2014-01-01T23:59:59.000Z

43

RAPID COMMUNICATIONS IN MASS SPECTROMETRY Rapid Commun. Mass Spectrom. 2005; 19: 32483252  

E-Print Network [OSTI]

to be that photofragment ions generated at this wavelength are similar to those from low- and high-energy CAD, and are thusRAPID COMMUNICATIONS IN MASS SPECTROMETRY Rapid Commun. Mass Spectrom. 2005; 19: 3248 of singly protonated peptides at 193 nm investigated with tandem time-of-flight mass spectrometry Jeong Hee

Kim, Myung Soo

44

RAPID COMMUNICATIONS IN MASS SPECTROMETRY Rapid Commun. Mass Spectrom. 2005; 19: 24812487  

E-Print Network [OSTI]

chromophore dissociated efficiently when a suf- ficiently high laser pulse energy was used. Also, the pulseRAPID COMMUNICATIONS IN MASS SPECTROMETRY Rapid Commun. Mass Spectrom. 2005; 19: 2481 time-of- flight (TOF) mass spectrometry of ions generated by matrix-assisted laser desorption

Kim, Myung Soo

45

Subcellular analysis by laser ablation electrospray ionization mass spectrometry  

DOE Patents [OSTI]

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

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

2014-12-02T23:59:59.000Z

46

Secondary Ion Mass Spectrometry Imaging of Dictyostelium discoideum Aggregation Streams  

SciTech Connect (OSTI)

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

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

2014-06-09T23:59:59.000Z

47

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

E-Print Network [OSTI]

and Energy Change at High Resolution Employing Enhanced Peptide Amide Deuterium Exchange- Mass Spectrometry (

Pantazatos, Dennis Peter

2006-01-01T23:59:59.000Z

48

Determination of the stellar (n,$\\gamma$) cross section of $^{54}Fe$ with accelerator mass spectrometry  

E-Print Network [OSTI]

Determination of the stellar (n,$\\gamma$) cross section of $^{54}Fe$ with accelerator mass spectrometry

Coquard, L; Dillmann, I; Wallner, A; Knie, K; Kutschera, W

2006-01-01T23:59:59.000Z

49

Aerosol mass spectrometry systems and methods  

DOE Patents [OSTI]

A system according to one embodiment includes a particle accelerator that directs a succession of polydisperse aerosol particles along a predetermined particle path; multiple tracking lasers for generating beams of light across the particle path; an optical detector positioned adjacent the particle path for detecting impingement of the beams of light on individual particles; a desorption laser for generating a beam of desorbing light across the particle path about coaxial with a beam of light produced by one of the tracking lasers; and a controller, responsive to detection of a signal produced by the optical detector, that controls the desorption laser to generate the beam of desorbing light. Additional systems and methods are also disclosed.

Fergenson, David P.; Gard, Eric E.

2013-08-20T23:59:59.000Z

50

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

SciTech Connect (OSTI)

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

Perdian, David C.

2009-08-19T23:59:59.000Z

51

Time-of-flight secondary ion mass spectrometry with transmission of energetic primary cluster ions through foil targets  

SciTech Connect (OSTI)

We developed time-of-flight (TOF) secondary ion (SI) mass spectrometry that provides informative SI ion mass spectra without needing a sophisticated ion beam pulsing system. In the newly developed spectrometry, energetic large cluster ions with energies of the order of sub MeV or greater are used as primary ions. Because their impacts on the target surface produce high yields of SIs, the resulting SI mass spectra are informative. In addition, the start signals necessary for timing information on primary ion incidence are provided by the detection signals of particles emitted from the rear surface of foil targets upon transmission of the primary ions. This configuration allows us to obtain positive and negative TOF SI mass spectra without pulsing system, which requires precise control of the primary ions to give the spectra with good mass resolution. We also successfully applied the TOF SI mass spectrometry with energetic cluster ion impacts to the chemical structure characterization of organic thin film targets.

Hirata, K., E-mail: k.hirata@aist.go.jp [National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Saitoh, Y.; Chiba, A.; Yamada, K.; Matoba, S.; Narumi, K. [Takasaki Advanced Radiation Research Institute (TARRI), Japan Atomic Energy Agency (JAEA), Takasaki, Gumma 370-1292 (Japan)] [Takasaki Advanced Radiation Research Institute (TARRI), Japan Atomic Energy Agency (JAEA), Takasaki, Gumma 370-1292 (Japan)

2014-03-15T23:59:59.000Z

52

Coming to a hospital near you: mass spectrometry imaging  

SciTech Connect (OSTI)

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

Bowen, Ben

2013-10-31T23:59:59.000Z

53

Coming to a hospital near you: mass spectrometry imaging  

ScienceCinema (OSTI)

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

Bowen, Ben

2014-06-24T23:59:59.000Z

54

Absorption Mode FT-ICR Mass Spectrometry Imaging  

SciTech Connect (OSTI)

Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power for molecular imaging experiments. This high mass resolving power ensures that closely spaced peaks at the same nominal mass are resolved for proper image generation. Typically higher magnetic fields are used to increase mass resolving power. However, a gain in mass resolving power can also be realized by phase correction of the data for absorption mode display. In addition to mass resolving power, absorption mode offers higher mass accuracy and signal-to-noise ratio over the conventional magnitude mode. Here we present the first use of absorption mode for Fourier transform ion cyclotron resonance mass spectrometry imaging. The Autophaser algorithm is used to phase correct each spectrum (pixel) in the image and then these parameters are used by the Chameleon work-flow based data processing software to generate absorption mode ?Datacubes? for image and spectral viewing. Absorption mode reveals new mass and spatial features that are not resolved in magnitude mode and results in improved selected ion image contrast.

Smith, Donald F.; Kilgour, David P.; Konijnenburg, Marco; O'Connor, Peter B.; Heeren, Ronald M.

2013-12-03T23:59:59.000Z

55

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

E-Print Network [OSTI]

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

Miranker, Andrew

56

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

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

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

57

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

SciTech Connect (OSTI)

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

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

2005-02-01T23:59:59.000Z

58

Testing atomic mass models with radioactive beams  

SciTech Connect (OSTI)

Significantly increased yields of new or poorly characterized exotic isotopes that lie far from beta-decay stability can be expected when radioactive beams are used to produce these nuclides. Measurements of the masses of these new species are very important. Such measurements are motivated by the general tendency of mass models to diverge from one another upon excursions from the line of beta-stability. Therefore in these regions (where atomic mass data are presently nonexistent or sparse) the models can be tested rigorously to highlight the features that affect the quality of their short-range and long-range extrapolation properties. Selection of systems to study can be guided, in part, by a desire to probe those mass regions where distinctions among mass models are most apparent and where yields of exotic isotopes, produced via radioactive beams, can be optimized. Identification of models in such regions that have good predictive properties will aid materially in guiding the selection of additional experiments which ultimately will provide expansion of the atomic mass database for further refinement of the mass models. 6 refs., 5 figs.

Haustein, P.E.

1989-01-01T23:59:59.000Z

59

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

60

Charge Prediction of Lipid Fragments in Mass Spectrometry  

SciTech Connect (OSTI)

An artificial neural network is developed for predicting which fragment is charged and which fragment is neutral for lipid fragment pairs produced from a liquid chromatography tandem mass spectrometry simulation process. This charge predictor is integrated into software developed at PNNL for in silico spectra generation and identification of metabolites known as Met ISIS. To test the effect of including charge prediction in Met ISIS, 46 lipids are used which show a reduction in false positive identifications when the charge predictor is utilized.

Schrom, Brian T.; Kangas, Lars J.; Ginovska, Bojana; Metz, Thomas O.; Miller, John H.

2011-12-18T23:59:59.000Z

Note: This page contains sample records for the topic "beam mass spectrometry" 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

Tissue Imaging Using Nanospray Desorption Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

We present the first results showing the ambient imaging of biological samples in their native environment using nanospray desorption ionization (nanoDESI) mass spectrometry. NanoDESI is an ambient pressure ionization technique that enables precise control of ionization of molecules from substrates. We demonstrate highly sensitive and robust analysis of tissue samples with high spatial resolution (<12 {mu}m) without sample preparation, which will be essential for applications in clinical diagnostics, drug discovery, molecular biology, and biochemistry.

Laskin, Julia; Heath, Brandi S.; Roach, Patrick J.; Cazares, Lisa H.; Semmes, O. John

2012-01-03T23:59:59.000Z

62

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. 2 figures, 3 tables.

Todd, P.J.; McKown, H.S.; Smith, D.H.

1982-04-26T23:59:59.000Z

63

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

E-Print Network [OSTI]

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

Manstein, Dietmar J.

64

BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT  

E-Print Network [OSTI]

BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT A.RASPEREZA DESY, Notkestrasse 85, D­22607#erential luminosity spectrum measurements and beam energy spread on the precision of the Higgs boson mass measurement possible impact of the beam related systematic errors on the Higgs boson mass measurement is discussed

65

Multielement ultratrace analysis of molybdenum with high performance secondary ion mass spectrometry  

SciTech Connect (OSTI)

Electron beam melting has been used to obtain ultrapure refractory metals that are gaining importance in metal oxide semiconductor--very large scale integration (MOS--VLSI) processing technology, fusion reactor technology, or as superconducting materials. Although the technology of electron beam melting is well established in the field of production of very clean refractory metals, little is known about the limitations of the method because the impurity level of the final products is frequently below the detection power of common methods for trace analysis. Characterization of these materials can be accomplished primarily by in situ methods like neutron activation analysis and mass spectrometric methods (glow discharge mass spectrometry (GDMS), secondary ion mass spectrometry (SIMS)). A suitable method for quantitative multielement ultratrace bulk analysis of molybdenum with SIMS has been developed. Detection limits of the analyzed elements from 10/sup -7/ g/g down to 10/sup -12/ g/g have been found. Additional information about the distribution of the trace elements has been accumulated.

Virag, A.; Friedbacher, G.; Grasserbauer, M.; Ortner, H.M.; Wilhartitz, P.

1988-07-01T23:59:59.000Z

66

Fourier transform mass spectrometry of high-mass biomolecules  

SciTech Connect (OSTI)

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

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

1993-03-01T23:59:59.000Z

67

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

SciTech Connect (OSTI)

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

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

2013-02-05T23:59:59.000Z

68

Fission Yield Measurements by Inductively Coupled Plasma Mass-Spectrometry  

SciTech Connect (OSTI)

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

69

Mass Spectrometry imaging of plant metabolites | The Ames Laboratory  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping the Nanoscale Landscape PrintSurveyMary K.MassSpectrometry

70

atomic mass spectrometry: Topics by E-print Network  

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

Negative *) Atomic composition Graham, Nick 3 Prospects in Analytical Atomic Spectrometry CERN Preprints Summary: Tendencies in five main branches of atomic spectrometry...

71

New developments in biochemical mass spectrometry: Electrospray ionization  

SciTech Connect (OSTI)

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

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

1990-05-01T23:59:59.000Z

72

Detection of methoxylated anions of fullerenes by electrospray ionization mass spectrometry  

SciTech Connect (OSTI)

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

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

1993-11-03T23:59:59.000Z

73

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

Office of Science (SC) Website

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

74

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

2011-06-21T23:59:59.000Z

75

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

DOE Patents [OSTI]

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

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

2011-11-29T23:59:59.000Z

76

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

DOE Patents [OSTI]

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

Vertes, Akos; Nemes, Peter

2014-08-19T23:59:59.000Z

77

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

78

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

79

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

80

BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT  

E-Print Network [OSTI]

BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT A.RASPEREZA DESY, Notkestrasse 85, D-22607 and differential luminosity spectrum measurements and beam energy spread on the precision of the Higgs boson mass such as Higgs boson mass, decay branching fractions and production rate. However, most of these studies did

Note: This page contains sample records for the topic "beam mass spectrometry" 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

Method for predicting peptide detection in mass spectrometry  

DOE Patents [OSTI]

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

82

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

SciTech Connect (OSTI)

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

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

2007-06-28T23:59:59.000Z

83

Low-level 14C measurements and Accelerator Mass Spectrometry  

SciTech Connect (OSTI)

Accelerator Mass Spectrometry (AMS) and isotope enrichment were used in 1991 to estimate that the 14C content of methane in natural gas was {<=}1.6x10-18 of the total carbon. The low content of 14C in underground hydrocarbons was verified later in the remarkable results from the Borexino test scintillation counter for solar neutrino studies. Since then studies of the 14C background problem have demonstrated that much of the background originally observed in the AMS measurements can, in principle, be eliminated. However, many difficulties and other backgrounds are to be faced as the limit for AMS is pushed still further towards possibly a ratio of < 10-21. These will be discussed.

Litherland, A.E.; Beukens, R.P.; Zhao, X.-L.; Kieser, W.E. [IsoTrace Laboratory, University of Toronto, Toronto, ON, M5S 1A7 (Canada); Gove, H.E. [IsoTrace Laboratory, University of Toronto, Toronto, ON, M5S 1A7 (Canada); Department of Physics and Astronomy, University of Rochester, Rochester, NY, 14627-0171 (United States)

2005-09-08T23:59:59.000Z

84

Dating Studies of Elephant Tusks Using Accelerator Mass Spectrometry  

SciTech Connect (OSTI)

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

Sideras-Haddad, E; Brown, T A

2002-10-03T23:59:59.000Z

85

Focus on Advancing High Performance Mass Spectrometry, Honoring Dr. Richard D. Smith, Recipient of the 2013 Award for a Distinguished Contribution in Mass Spectrometry  

SciTech Connect (OSTI)

This special focus issue of the Journal of the American Society for Mass Spectrometry celebrates the accomplishments of Dr. Richard D. Smith, the recipient of the 2013ASMS Award for a Distinguished Contribution in Mass Spectrometry, and who serves as a Battelle Fellow, Chief Scientist in the Biological Sciences Division, and Director of Proteomics Research at Pacific Northwest National Laboratory (PNNL) in Richland, WA. The award is for his development of the electrodynamic ion funnel.

Baker, Erin Shammel; Muddiman, David C.; Loo, Joseph

2014-12-01T23:59:59.000Z

86

Are Cluster Ion Analysis Beams Good Choices for Hydrogen Depth...  

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

Cluster Ion Analysis Beams Good Choices for Hydrogen Depth Profiling Using Time-of-Flight Secondary Ion Mass Spectrometry? Are Cluster Ion Analysis Beams Good Choices for Hydrogen...

87

In situ characterization of GaN quantum dot growth with reflection high-energy electron diffraction and line-of-sight mass spectrometry  

E-Print Network [OSTI]

mass spectrometry and re?ection high-energy electronmass spectrometry ?QMS? and re?ection high-energy electron

Brown, J S; Koblmuller, G; Averbeck, R; Riechert, H; Speck, J S

2006-01-01T23:59:59.000Z

88

Ga adsorbate on (0001) GaN: In situ characterization with quadrupole mass spectrometry and reflection high-energy electron diffraction  

E-Print Network [OSTI]

mass spectrometry and re?ection high-energy electronmass spectrometry ?QMS? and re?ection high-energy electron

Brown, J S; Koblmuller, G; Wu, F; Averbeck, R; Riechert, H; Speck, J S

2006-01-01T23:59:59.000Z

89

International Journal of Mass Spectrometry 288 (2009) 1621 Contents lists available at ScienceDirect  

E-Print Network [OSTI]

International Journal of Mass Spectrometry 288 (2009) 16­21 Contents lists available at ScienceDirect International Journal of Mass Spectrometry journal homepage: www.elsevier.com/locate/ijms Utility of reaction-MS2 and PD-MS3 were combined, demonstrating the utility of transient ion detection by PD-MS3

Kim, Myung Soo

90

International Journal of Mass Spectrometry 287 (2009) 105113 Contents lists available at ScienceDirect  

E-Print Network [OSTI]

to deposit more internal energy into these clusters, providing access to alternative, high energyInternational Journal of Mass Spectrometry 287 (2009) 105­113 Contents lists available at ScienceDirect International Journal of Mass Spectrometry journal homepage: www.elsevier.com/locate/ijms Influence of cluster

Wysocki, Vicki H.

91

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

E-Print Network [OSTI]

OpenMSI: A High-Performance Web-Based Platform for Mass Spectrometry Imaging Oliver RĂĽbel, AnnetteMSI: A High-Performance Web-Based Platform for Mass Spectrometry Imaging Oliver Rubel,* Annette Greiner. Acknowledgements: This work was supported by and used resources of the National Energy Research Scientific

92

JOURNAL OF MASS SPECTROMETRY, VOL. 31, 339-350 (1996) SPECIAL FEATURE  

E-Print Network [OSTI]

fragmentation mechanisms of protonated peptides is discussed and demonstrated. High internal energy deposition in understandingpeptide fragmentation by low-energy tandem mass spectrometry. KEYWORDS: surface-induced dissociationJOURNAL OF MASS SPECTROMETRY, VOL. 31, 339-350 (1996) SPECIAL FEATURE: PERSPECTIVE Surface

Wysocki, Vicki H.

93

Human vitamin B12 absorption measurement by accelerator mass spectrometry using specifically  

E-Print Network [OSTI]

Human vitamin B12 absorption measurement by accelerator mass spectrometry using specifically for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551 is the suspected cause. The test involves ingestion of a physiological quantity of B12 labeled with gamma

California at Davis, University of

94

Explorations of Functionalized Gold Nanoparticle Surface Chemistry for Laser Desorption Ionization Mass Spectrometry Applications  

E-Print Network [OSTI]

EXPLORATIONS OF FUNCTIONALIZED GOLD NANOPARTICLE SURFACE CHEMISTRY FOR LASER DESORPTION IONIZATION MASS SPECTROMETRY APPLICATIONS A Thesis by MARIO ESTUARDO GOMEZ HERNANDEZ Submitted to the Office... DESORPTION IONIZATION MASS SPECTROMETRY APPLICATIONS A Thesis by MARIO ESTUARDO GOMEZ HERNANDEZ Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree...

Gomez Hernandez, Mario 1980-

2012-07-11T23:59:59.000Z

95

Transition of Iodine Analysis to Accelerator Mass Spectrometry  

SciTech Connect (OSTI)

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

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

2012-09-01T23:59:59.000Z

96

Laser desorption mass spectrometry for fast DNA analysis  

SciTech Connect (OSTI)

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

97

Matrix Effects in Biological Mass Spectrometry Imaging: Identification and Compensation  

SciTech Connect (OSTI)

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

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

2014-07-21T23:59:59.000Z

98

Trace elements in coal by glow discharge mass spectrometry  

SciTech Connect (OSTI)

A need and a demand exist for determining trace elements in coal and coal related by-products, especially those elements which may potentially be a health hazard. The provisions of the 1990 clean air act require that the EPA evaluate the emissions of electric utilities for trace elements and other potentially hazardous organic compounds. The coal fired electric utility industry supplies roughly 60% of the total generating capacity of 2,882,525 million kilowatt hours (nearly 3 trillion kilowatt hours) generated in the U.S. This is accomplished by 414 power plants scattered across the country that burned 813,508,000 short tons of coal in 1993. The relative volatility of some inorganic constituents in coal makes them more prone to be emitted to the atmosphere following combustion. The production of analytical data for trace elements is known to be a difficult task in coal and by-products of coal combustion (fly ash, bottom ash, gas streams, etc.), in terms of both sample collection and analytical determinations. There are several common analytical methods available to the analyst to determine trace elements in coal and coal by-products. In general analytical germs, the material to be analyzed can be totally solubilized (or extracted), or the elements analytes can be determined in the material as a solid. A relatively new elemental technique, Glow Discharge Mass Spectrometry (GDMS) can be used with solids as well. This new analytical technique had never before been applied directly to coal. The radio frequency-glow discharge quadropole mass spectrometer was used to analyze coal directly for the first time ever by rf-GDMS. The rf-GDMS technique is described.

Jacobs, M.L.; Wilson, C.R.; Pestovich, J. Jr. [WAL Inc., Wheat Ridge, CO (United States)] [and others

1995-08-01T23:59:59.000Z

99

Prospects for large dynamic range isotope analysis using photon burst mass spectrometry  

SciTech Connect (OSTI)

Photon Burst Mass Spectrometry is a relatively new and untried method which may complement and extend the impressive achievements of Resonance Ionization Mass Spectrometry and Accelerator Mass Spectrometry in the field of large dynamic range isotope analysis. Theoretical predictions indicate that measurements in the 10/sup /minus/11/ to 10/sup /minus/15/ range are possible in a reasonable period of time with zero background. Experimentally only the very first demonstrations of PBMS with stable isotopes have been completed. 8 refs., 1 fig., 1 tab.

Fairbank, W.M. Jr.; LaBelle, R.D.; Keller, R.A.; Miller, C.M.; Poths, J.; Fearey, B.L.

1988-01-01T23:59:59.000Z

100

Fractal morphology, imaging and mass spectrometry of single aerosol particles in flight (CXIDB ID 16)  

DOE Data Explorer [Office of Scientific and Technical Information (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 "beam mass spectrometry" 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

A postsource decay study of bradykinin by Matrix-assisted laser desorption ionization mass spectrometry  

E-Print Network [OSTI]

Matrix-assisted laser desorption/ionization (MALDI) with time-of-flight (TOF) mass spectrometry is a very powerful technique for the analysis of peptides and proteins. Fragmentation reactions of the protonated analyte molecule, [M+H]+ ions...

Wei, Xiaona

1996-01-01T23:59:59.000Z

102

The effect of solvent on matrix-assisted laser desorption ionization mass spectrometry  

E-Print Network [OSTI]

Since its introduction in 1988, matrix-assisted laser desorption/ionization mass spectrometry (MALDI) has developed into a useful analytical tool in the biological field. The work presented here focuses on the effect of solvent on MALDI ion yields...

Campo, Karen Kay

1996-01-01T23:59:59.000Z

103

Development of Advanced Optics and High Resolution Instrumentation for Mass Spectrometry Based Proteomics  

E-Print Network [OSTI]

Imaging mass spectrometry (MS) analysis allows scientists the ability to obtain spatial and chemical information of analytes on a wide variety of surfaces. The ability to image biological analytes is an important tool in many areas of life science...

Sherrod, Stacy D.

2010-01-14T23:59:59.000Z

104

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.

105

SwePep, a Database Designed for Endogenous Peptides and Mass Spectrometry*  

E-Print Network [OSTI]

SwePep, a Database Designed for Endogenous Peptides and Mass Spectrometry* Maria Fa¨ lth§, Karl Sko¨ ld§, Mathias Norrman, Marcus Svensson§, David Fenyo¨ , and Per E. Andren§** A new database, Swe the experimental peptide masses are compared with the peptide masses stored in the database both with and without

Chait, Brian T.

106

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

SciTech Connect (OSTI)

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

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

2010-06-23T23:59:59.000Z

107

High-Speed Tandem Mass Spectrometric in Situ Imaging by Nanospray Desorption Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

Nanospray desorption electrospray ionization (nano-DESI) combined with tandem mass spectrometry (MS/MS), high-resolution mass analysis (m/m=17,500 at m/z 200), and rapid spectral acquisition enabled simultaneous imaging and identification of more than 300 molecules from 92 selected m/z windows (± 1 Da) with a spatial resolution of better than 150 um. Uterine sections of implantation sites on day 6 of pregnancy were analyzed in the ambient environment without any sample pre-treatment. MS/MS imaging was performed by scanning the sample under the nano-DESI probe at 10 um/s while acquiring higher-energy collision-induced dissociation (HCD) spectra for a targeted inclusion list of 92 m/z values at a rate of ~6.3 spectra/s. Molecular ions and their corresponding fragments, separated using high-resolution mass analysis, were assigned based on accurate mass measurement. Using this approach, we were able to identify and image both abundant and low-abundance isobaric species within each m/z window. MS/MS analysis enabled efficient separation and identification of isobaric sodium and potassium adducts of phospholipids. Furthermore, we identified several metabolites associated with early pregnancy and obtained the first 2D images of these molecules.

Lanekoff, Ingela T.; Burnum-Johnson, Kristin E.; Thomas, Mathew; Short, Joshua TL; Carson, James P.; Cha, Jeeyeon; Dey, Sudhansu K.; Yang, Pengxiang; Prieto Conaway, Maria C.; Laskin, Julia

2013-10-15T23:59:59.000Z

108

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network [OSTI]

Gamma Ray Spectrometry . . . . . . . . . . . . . . . . . . .29, 30] Gamma Ray Spectrometry Gamma ray spectrometry willare measured by gamma spectrometry and compared to model

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

109

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

E-Print Network [OSTI]

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

110

International Journal of Mass Spectrometry 219 (2002) 7377 Protein charge transport in gas phase  

E-Print Network [OSTI]

temperature limit, the rotational energy can be transferred with very high efficiency and hence one obtainsInternational Journal of Mass Spectrometry 219 (2002) 73­77 Protein charge transport in gas phase high charge transport efficiency. (Int J Mass Spectrom 219 (2002) 73­77) © 2002 Elsevier Science B

Sheu, Sheh-Yi

111

In situ UPb dating of micro-baddeleyite by secondary ion mass spectrometry Axel K. Schmitt a,  

E-Print Network [OSTI]

In situ U­Pb dating of micro-baddeleyite by secondary ion mass spectrometry Axel K. Schmitt a secondary ion mass spectrometry (SIMS) in situ analysis of ng-mass crystals that cannot be efficiently conventional mineral separation methods are not optimized for recovery of such small grains, techniques

112

B American Society for Mass Spectrometry, 2012 DOI: 10.1007/s13361-012-0404-0  

E-Print Network [OSTI]

pI, mobile phase pH) [12], ion suppression of co-eluting analytes [13], and mobile phase flow rateB American Society for Mass Spectrometry, 2012 DOI: 10.1007/s13361-012-0404-0 J. Am. Soc. Mass Improves Peptide Identification by Tandem Mass Spectrometry Jesse G. Meyer, Elizabeth A. Komives Department

Komives, Elizabeth A.

113

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

SciTech Connect (OSTI)

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

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

1995-12-31T23:59:59.000Z

114

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

SciTech Connect (OSTI)

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

Maxwell, S.; Jones, V.

2009-05-27T23:59:59.000Z

115

Department of Chemistry Mass Spectrometry Sample Submission Form  

E-Print Network [OSTI]

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

Simons, Jack

116

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

117

Laser photoionization time-of-flight mass spectrometry of nitrated polycyclic aromatic hydrocarbons and nitrated heterocyclic compounds. Master's thesis  

SciTech Connect (OSTI)

Partial Contents: Laser Desorption-Laser Photoionization Time-of-Flight Mass Spectrometry; Basic Principles of TOFMS; Factors Affecting Flight Time; Source of Broadening; Laser Desorption; Theory of Multiphoton Ionization: Application to Mass Spectrometry; Quantum Theory of MPI; Time-Dependent Perturbation Theory; Time-Dependent Coefficients; Probability of a Two-Photon Process; and Attributes of R2PI.

Noyes, R.A.

1993-01-01T23:59:59.000Z

118

Examination of the rate of peptide biosynthesis in neuroendocrine cell lines using a stable isotopic label and mass spectrometry  

E-Print Network [OSTI]

isotopic label and mass spectrometry Fa-Yun Che,*,1 Quan Yuan,* ,1 Elena Kalinina* and Lloyd D. Fricker-Leu) and used mass spectrometry to measure the biosynthetic rate of c-lipotropin in the AtT-20 cell lines. Keywords: carboxypeptidase, gamma-lipotropin, insulin, prohormone convertase, proinsulin

Tian, Weidong

119

International Journal of Mass Spectrometry 316318 (2012) 259267 Contents lists available at SciVerse ScienceDirect  

E-Print Network [OSTI]

International Journal of Mass Spectrometry 316­318 (2012) 259­267 Contents lists available at SciVerse ScienceDirect International Journal of Mass Spectrometry journal homepage: www.elsevier.com/locate/ijms Influence of a gamma amino acid on the structures and reactivity of peptide a3 ions Matthew C. Berniera

Wysocki, Vicki H.

2012-01-01T23:59:59.000Z

120

Opportunistic Mass Measurements at the Holifield Radioactive Ion Beam Facility  

SciTech Connect (OSTI)

A technique for measuring mass differences has been developed at the Holifield Radioactive Ion Beam Facility (HRIBF) that requires no specialized equipment. Mass differences are measured as position differences between known and unknown-mass isobars, dispersed at the image of the energy-analyzing magnet following the 25MV tandem post-accelerator, and identified by an energy-loss measurement. The technique has been demonstrated on neutron-rich 77 79Cu and 83 86Ge isotopes produced using the isotope separator online (ISOL) method with the 238U(p,fission) reaction, where a mass accuracy of 500 keV was achieved. These nuclides are well suited to the measurement technique, as they readily migrate out of the production target and to the ion source and comprise the most neutron-rich elements of the isobarically mixed beam. Because modest precision mass values can be obtained with only a few tens of counts of the nuclide of interest among orders of magnitude more of the isobaric neighbors closer to stability, the sensitivity of this technique makes it appropriate for initial mass measurements far from stability.

Hausladen, Paul [ORNL; Beene, James R [ORNL; Galindo-Uribarri, Alfredo {nmn} [ORNL; Larochelle, Y [University of Tennessee, Knoxville (UTK); Liang, J Felix [ORNL; Mueller, Paul Edward [ORNL; Shapira, Dan [ORNL; Stracener, Daniel W [ORNL; Thomas, J. S. [Rutgers University; Varner Jr, Robert L [ORNL; Wollnik, Hermann [ORNL

2006-01-01T23:59:59.000Z

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


121

Tandem Mass Spectrometry for the Direct Assay of Lysosomal Enzymes in  

E-Print Network [OSTI]

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

Gelb, Michael

122

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

E-Print Network [OSTI]

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

Entekhabi, Dara

123

Two-Step Laser Mass Spectrometry of Asphaltenes Andrew E. Pomerantz,*,  

E-Print Network [OSTI]

that high pulse energy and sample concentration promote aggregation of asphaltenes in the plasma plumeTwo-Step Laser Mass Spectrometry of Asphaltenes Andrew E. Pomerantz,*, Matthew R. Hammond, Amy L- heptane, asphaltenes are a highly aromatic, polydisperse mixture consisting of the heaviest and most polar

Zare, Richard N.

124

Surface Analysis by Highly Charged Ion Based Secondary Ion Mass Spectrometry  

E-Print Network [OSTI]

Surface Analysis by Highly Charged Ion Based Secondary Ion Mass Spectrometry T. Schenkel,1 A high vacuum (10^8 torr). In posi- tive polarity, HCI can be decelerated to an impact energy of $1 ke in the interaction of slow (u highly charged ions (e.g., Au69+ ) with solid surfaces increases secondary

125

ORGANIC MASS SPECTROMETRY, VOL. 21, 193-195 (1986) Energy Deposition in [Fe(CO),] ''Upon  

E-Print Network [OSTI]

ORGANIC MASS SPECTROMETRY, VOL. 21, 193-195 (1986) Energy Deposition in [Fe(CO),] ''Upon Collision distributions associated with gas-phase collisional activation using both low and high ion kinetic energies, and the high internal energies accessible, make the ionlsurface collision process superior to gas

Wysocki, Vicki H.

126

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

E-Print Network [OSTI]

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

Hamann, Bernd

127

Characterization of Individual Nanoparticles and Applications of Nanoparticles in Mass Spectrometry  

E-Print Network [OSTI]

information from single massive cluster impacts. The clusters used in this secondary ion 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...

Rajagopal Achary, Sidhartha Raja

2011-08-08T23:59:59.000Z

128

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

E-Print Network [OSTI]

. The application of hydrogen/deuterium exchange mass spectrometry (H/D-MS) to study IDPs is presented in this dissertation. Results that demonstrate improvements to the H/D-MS method are also presented. A thermoelectrically cooled refrigeration system was developed...

Keppel, Theodore Robert

2013-05-31T23:59:59.000Z

129

Apparatus for preparing a sample for mass spectrometry  

DOE Patents [OSTI]

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

Villa-Aleman, E.

1994-05-10T23:59:59.000Z

130

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

E-Print Network [OSTI]

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

Piper, Duane Gilbert

1976-01-01T23:59:59.000Z

131

Synchrotron based mass spectrometry to investigate the molecular properties of mineral-organic associations  

SciTech Connect (OSTI)

Soil organic matter (OM) is important because its decay drives life processes in the biosphere. Analysis of organic compounds in geological systems is difficult because of their intimate association with mineral surfaces. To date there is no procedure capable of quantitatively separating organic from mineral phases without creating artifacts or mass loss. Therefore, analytical techniques that can (a) generate information about both organic and mineral phases simultaneously and (b) allow the examination of predetermined high-interest regions of the sample as opposed to conventional bulk analytical techniques are valuable. Laser Desorption Synchrotron Postionization (synchrotron-LDPI) mass spectrometry is introduced as a novel analytical tool to characterize the molecular properties of organic compounds in mineral-organic samples from terrestrial systems, and it is demonstrated that when combined with Secondary Ion Mass Spectrometry (SIMS), can provide complementary information on mineral composition. Mass spectrometry along a decomposition gradient in density fractions, verifies the consistency of our results with bulk analytical techniques. We further demonstrate that by changing laser and photoionization energies, variations in molecular stability of organic compounds associated with mineral surfaces can be determined. The combination of synchrotron-LDPI and SIMS shows that the energetic conditions involved in desorption and ionization of organic matter may be a greater determinant of mass spectral signatures than the inherent molecular structure of the organic compounds investigated. The latter has implications for molecular models of natural organic matter that are based on mass spectrometric information.

Liu, Suet Yi; Kleber, Markus; Takahashi, Lynelle K.; Nico, Peter; Keiluweit, Marco; Ahmed, Musahid

2013-04-01T23:59:59.000Z

132

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

SciTech Connect (OSTI)

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

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

1996-02-01T23:59:59.000Z

133

National Centre for Biological Sciences Mass Spectrometry Facility  

E-Print Network [OSTI]

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

Bhalla, Upinder S.

134

Evaluation of Hypervelocity Gold Nanoparticles for Nanovolume Surface Mass Spectrometry  

E-Print Network [OSTI]

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

DeBord, John 1986-

2012-08-16T23:59:59.000Z

135

Explanatory Optimization of Protein Mass Spectrometry via Genetic Search  

E-Print Network [OSTI]

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

Fernandez, Thomas

136

Coulomb crystal mass spectrometry in a digital ion trap  

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

137

Top-Down Mass Spectrometry Imaging of Intact Proteins by LAESI FT-ICR MS  

E-Print Network [OSTI]

Laser Ablation Electrospray Ionization is a recent development in mass spectrometry imaging. It has been shown that lipids and small metabolites can be imaged in various samples such as plant material, tissue sections or bacterial colonies without anysample pre-treatment. Further, laser ablation electrospray ionization has been shown to produce multiply charged protein ions from liquids or solid surfaces. This presents a means to address one of the biggest challenges in mass spectrometry imaging; the identification of proteins directly from biological tissue surfaces. Such identification is hindered by the lack of multiply charged proteins in common MALDI ion sources and the difficulty of performing tandem MS on such large, singly charged ions. We present here top-down identification of intact proteins from tissue with a LAESI ion source combined with a hybrid ion-trap FT-ICR mass spectrometer. The performance of the system was first tested with a standard protein with ECD and IRMPD fragmentation to prove the...

Kiss, András; Reschke, Brent R; Powell, Matthew J; Heeren, Ron M A

2013-01-01T23:59:59.000Z

138

Plume collimation for laser ablation electrospray ionization mass spectrometry  

DOE Patents [OSTI]

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

Vertes, Akos; Stolee, Jessica A.

2014-09-09T23:59:59.000Z

139

Sampling probe for microarray read out using electrospray mass spectrometry  

DOE Patents [OSTI]

An automated electrospray based sampling system and method for analysis obtains samples from surface array spots having analytes. The system includes at least one probe, the probe including an inlet for flowing at least one eluting solvent to respective ones of a plurality of spots and an outlet for directing the analyte away from the spots. An automatic positioning system is provided for translating the probe relative to the spots to permit sampling of any spot. An electrospray ion source having an input fluidicly connected to the probe receives the analyte and generates ions from the analyte. The ion source provides the generated ions to a structure for analysis to identify the analyte, preferably being a mass spectrometer. The probe can be a surface contact probe, where the probe forms an enclosing seal along the periphery of the array spot surface.

Van Berkel, Gary J.

2004-10-12T23:59:59.000Z

140

B American Society for Mass Spectrometry, 2011 DOI: 10.1007/s13361-011-0115-y  

E-Print Network [OSTI]

@snu.ac.kr #12;ionization, (B) low-energy multiple CA in the plume, and (C) post-source high-energy CAB American Society for Mass Spectrometry, 2011 DOI: 10.1007/s13361-011-0115-y J. Am. Soc. Mass-Recognized in MALDI Mass Spectrometry Yong Jin Bae,1 Jeong Hee Moon,2 Myung Soo Kim1 1 Department of Chemistry, Seoul

Kim, Myung Soo

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


141

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

SciTech Connect (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

142

Matrix effects in inductively coupled plasma mass spectrometry  

SciTech Connect (OSTI)

The inductively coupled plasma is an electrodeless discharge in a gas (usually Ar) at atmospheric pressure. Radio frequency energy generated by a RF power source is inductively coupled to the plasma gas through a water cooled load coil. In ICP-MS the {open_quotes}Fassel{close_quotes} TAX quartz torch commonly used in emission is mounted horizontally. The sample aerosol is introduced into the central flow, where the gas kinetic temperature is about 5000 K. The aerosol is vaporized, atomized, excited and ionized in the plasma, and the ions are subsequently extracted through two metal apertures (sampler and skimmer) into the mass spectrometer. In ICP-MS, the matrix effects, or non-spectroscopic interferences, can be defined as the type of interferences caused by dissolved concomitant salt ions in the solution. Matrix effects can be divided into two categories: (1) signal drift due to the deposition of solids on the sampling apertures; and/or (2) signal suppression or enhancement by the presence of the dissolved salts. The first category is now reasonably understood. The dissolved salts, especially refractory oxides, tend to deposit on the cool tip of the sampling cone. The clogging of the orifices reduces the ion flow into the ICP-MS, lowers the pressure in the first stage of ICP-MS, and enhances the level of metal oxide ions. Because the extent of the clogging increases with the time, the signal drifts down. Even at the very early stage of the development of ICP-MS, matrix effects had been observed. Houk et al. found out that the ICP-MS was not tolerant to solutions containing significant amounts of dissolved solids.

Chen, Xiaoshan

1995-07-07T23:59:59.000Z

143

Mass Spectrometry Data from the Biological MS Data and Software Distribution Center  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

The mass spectrometry capabilities at Pacific Northwest National Laboratory (PNNL) are primarily applied to biological research, with an emphasis on proteomics and metabolomics. Many of these cutting-edge mass spectrometry capabilities and bioinformatics methods are housed in the Department of Energy's Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility operated by PNNL. These capabilities have been developed and acquired through cooperation between the EMSL national scientific user program and PNNL programmatic research. At the website of the Biological MS Data and Software Distribution Center, the following resources are made available: PNNL-developed software tools and source code, PNNL-generated raw data and processed results, links to publications that used the data and results available on this site, and tutorials and user manuals. [taken from http://omics.pnl.gov/

Anderson, Gordon

144

Analysis of a Fossil Bone from the Archaeological Settlement Malu Rosu, Romania by Accelerator Mass Spectrometry  

E-Print Network [OSTI]

A fossil bone from the archaeological site Malu Rosu Giurgiu, in Romania has been analyzed by accelerator mass spectrometry to estimate its age by determining its $^{14}$C content. The radiocarbon age of the bone is in agreement with the date obtained by the method for age determination, based on fluorine content. This is the first radiocarbon dating for the final Neolithic period, for this archaeological settlement in the Romanian region.

Agata Olariu; Ion V. Popescu; Ragnar Hellborg; Kristina Stenström; Mikko Faarinen; Per Persson; Bengt Erlandsson; Göran Skog; Emilian Alexandrescu

2001-03-13T23:59:59.000Z

145

Characterization of surface and layered films with cluster secondary ion mass spectrometry  

E-Print Network [OSTI]

.................................... 84 1 CHAPTER I INTRODUCTION Secondary ion mass spectrometry (SIMS) is well recognized a sensitive surface analysis method [1]. It utilizes energetic charged particles (primary ions) to probe surfaces. Impacts from the high energy, high... surprisingly, the most efficient projectiles for this purpose are those depositing a high density of energy. Desorption with keV and MeV Projectiles SIMS operates in two different modes: dynamic SIMS and static SIMS. The major difference between these modes...

Li, Zhen

2008-10-10T23:59:59.000Z

146

High-Resolution Desorption Electrospray Ionization Mass Spectrometry for Chemical Characterization of Organic Aerosols  

SciTech Connect (OSTI)

Characterization of the chemical composition and chemical transformations of secondary organic aerosol (SOA) is both a major challenge and the area of greatest uncertainty in current aerosol research. This study presents the first application of desorption electrospray ionization combined with high-resolution mass spectrometry (DESI-MS) for detailed chemical characterization and studies of chemical aging of OA collected on Teflon substrates. DESI-MS offers unique advantages both for detailed characterization of chemically labile components in OA that cannot be detected using more traditional electrospray ionization mass spectrometry (ESI-MS) and for studying chemical aging of OA. DESI-MS enables rapid characterization of OA samples collected on substrates by eliminating the sample preparation stage. In addition, it enables detection and structural characterization of chemically labile molecules in OA samples by minimizing the residence time of analyte in the solvent. SOA produced by the ozonolysis of limonene (LSOA) was allowed to react with gaseous ammonia. Chemical aging resulted in measurable changes in the optical properties of LSOA observed using UV- visible spectroscopy. DESI-MS combined with tandem mass spectrometry experiments (MS/MS) enabled identification of species in aged LSOA responsible for absorption of the visible light. Detailed analysis of the experimental data allowed us to identify chemical changes induced by reactions of LSOA constituents with ammonia and distinguish between different mechanisms of chemical aging.

Laskin, Julia; Laskin, Alexander; Roach, Patrick J.; Slysz, Gordon W.; Anderson, Gordon A.; Nizkorodov, Serguei; Bones, David L.; Nguyen, Lucas

2010-03-01T23:59:59.000Z

147

2?52Cf plasma desorption mass spectrometry of metal clusters  

E-Print Network [OSTI]

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

Hughes, Janita Muriel

1991-01-01T23:59:59.000Z

148

Statistical Methods for the Analysis of Mass Spectrometry-based Proteomics Data  

E-Print Network [OSTI]

. This research is supported by the. This work was sponsored by a subcontract from PNNL and by the NIH R25-CA-90301 training grant at TAMU. Additional support was provided by KAUST-IAMCS Innovation grant, by NIH grant DK070146 and by the National Institute...-MS Liquid chromatographyCMass spectrometry M/Z Mass over charge ratio NET Normalized elution time NMC Number of missed cleavage sites NTE Number of tryptic ends PEP Posterior error probability PM Potential matches PMF Probability mass function PNNL...

Wang, Xuan

2012-07-16T23:59:59.000Z

149

Facilities: NHMFL 9.4 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer Citation: Atmospheric Pressure Laser-Induced Acoustic Desorption Chemical Ionization Mass Spectrometry  

E-Print Network [OSTI]

. Rodgers, & Alan G. Marshall, Analytical Chemistry 84, 7131-7137 (2012). Figure 1. Schematic diagram hydrocarbons (the primary components of gasoline) are difficult to analyze by mass spectrometry, because

Weston, Ken

150

An Analysis of Nuclear Fuel Burnup in the AGR 1 TRISO Fuel Experiment Using Gamma Spectrometry, Mass Spectrometry, and Computational Simulation Techniques  

SciTech Connect (OSTI)

AGR 1 was the first in a series of experiments designed to test US TRISO fuel under high temperature gas-cooled reactor irradiation conditions. This experiment was irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) and is currently undergoing post irradiation examination (PIE) at INL and Oak Ridge National Laboratory. One component of the AGR 1 PIE is the experimental evaluation of the burnup of the fuel by two separate techniques. Gamma spectrometry was used to non destructively evaluate the burnup of all 72 of the TRISO fuel compacts that comprised the AGR 1 experiment. Two methods for evaluating burnup by gamma spectrometry were developed, one based on the Cs 137 activity and the other based on the ratio of Cs 134 and Cs 137 activities. Burnup values determined from both methods compared well with the values predicted from simulations. The highest measured burnup was 20.1 %FIMA for the direct method and 20.0 %FIMA for the ratio method (compared to 19.56% FIMA from simulations). An advantage of the ratio method is that the burnup of the cylindrical fuel compacts can determined in small (2.5 mm) axial increments and an axial burnup profile can be produced. Destructive chemical analysis by inductively coupled mass spectrometry (ICP MS) was then performed on selected compacts that were representative of the expected range of fuel burnups in the experiment to compare with the burnup values determined by gamma spectrometry. The compacts analyzed by mass spectrometry had a burnup range of 19.3 % FIMA to 10.7 % FIMA. The mass spectrometry evaluation of burnup for the four compacts agreed well with the gamma spectrometry burnup evaluations and the expected burnup from simulation. For all four compacts analyzed by mass spectrometry, the maximum range in the three experimentally determined values and the predicted value was 6% or less. The results confirm the accuracy of the nondestructive burnup evaluation from gamma spectrometry for TRISO fuel compacts across a burnup range of approximately 10 to 20 % FIMA and also validate the approach used in the physics simulation of the AGR 1 experiment.

Jason M. Harp; Paul A. Demkowicz; Phillip L. Winston; James W. Sterbentz

2014-10-01T23:59:59.000Z

151

Mass spectrometer with electron source for reducing space charge effects in sample beam  

DOE Patents [OSTI]

A mass spectrometer includes an ion source which generates a beam including positive ions, a sampling interface which extracts a portion of the beam from the ion source to form a sample beam that travels along a path and has an excess of positive ions over at least part of the path, thereby causing space charge effects to occur in the sample beam due to the excess of positive ions in the sample beam, an electron source which adds electrons to the sample beam to reduce space charge repulsion between the positive ions in the sample beam, thereby reducing the space charge effects in the sample beam and producing a sample beam having reduced space charge effects, and a mass analyzer which analyzes the sample beam having reduced space charge effects.

Houk, Robert S.; Praphairaksit, Narong

2003-10-14T23:59:59.000Z

152

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

SciTech Connect (OSTI)

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

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

2005-05-16T23:59:59.000Z

153

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

SciTech Connect (OSTI)

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

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

1994-12-31T23:59:59.000Z

154

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

SciTech Connect (OSTI)

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

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

1995-08-30T23:59:59.000Z

155

Controlled-Resonant Surface Tapping-Mode Scanning Probe Electrospray Ionization Mass Spectrometry Imaging  

SciTech Connect (OSTI)

This paper reports on the advancement of a controlled-resonance surface tapping-mode single capillary liquid junction extraction/ESI emitter for mass spectrometry imaging. The basic instrumental setup and the general operation of the system were discussed and optimized performance metrics were presented. The ability to spot sample, lane scan and chemically image in an automated and controlled fashion were demonstrated. Rapid, automated spot sampling was demonstrated for a variety of compound types including the cationic dye basic blue 7, the oligosaccharide cellopentaose, and the protein equine heart cytochrome c. The system was used for lane scanning and chemical imaging of the cationic dye crystal violet in inked lines on glass and for lipid distributions in mouse brain thin tissue sections. Imaging of the lipids in mouse brain tissue under optimized conditions provided a spatial resolution of approximately 35 m based on the ability to distinguish between features observed both in the optical and mass spectral chemical images. The sampling spatial resolution of this system was comparable to the best resolution that has been reported for other types of atmospheric pressure liquid extraction-based surface sampling/ionization techniques used for mass spectrometry imaging.

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

2014-01-01T23:59:59.000Z

156

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

SciTech Connect (OSTI)

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

157

Method Development of Characterization of N-linked Glycoproteins in Mass Spectrometry  

E-Print Network [OSTI]

in the instruments used in my research. I would also like to thank Dr. Barton F. Haynes, Dr. Hua-Xin Liao, and Laura L. Sutherland at Duke Human Vaccine Research Institute (Duke University, Durham, NC) for supplying HIV Env proteins for my research. I warmly thank...…………………………………………………………………………...115 V. Determination of disulfide bond arrangement of HIV Env protein CON-S gp140 ?CFI by LC/ESI-FTICR mass spectrometry. 5.1. Introduction…………………………………………………………………………120 5.2. Experimental section……………………………………………………………...124 5.3. Results...

Zhang, Ying

2008-02-25T23:59:59.000Z

158

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

SciTech Connect (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

159

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

DOE Patents [OSTI]

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

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

1999-01-01T23:59:59.000Z

160

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, VOL. 7, 693-699 (1993) Collisions of C&*and Cii at Fluorinated and  

E-Print Network [OSTI]

energy is relatively high, typically 12-15% for small molecules.' Thus, if the efficiency of energy & Sons, Ltd. (e.g. masses areater than 200u) strike surfaces." The high relative energy transferRAPID COMMUNICATIONS IN MASS SPECTROMETRY, VOL. 7, 693-699 (1993) Collisions of C&*and Cii

Wysocki, Vicki H.

Note: This page contains sample records for the topic "beam mass spectrometry" 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

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network [OSTI]

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

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

162

Nuclear-mass dependence of azimuthal beam-helicity and beam-charge asymmetries in deeply virtual Compton scattering  

E-Print Network [OSTI]

The nuclear-mass dependence of azimuthal cross section asymmetries with respect to charge and longitudinal polarization of the lepton beam is studiedfor hard exclusive electroproduction of real photons. The observed beam-charge and beam-helicity asymmetries are attributed to the interference between the Bethe-Heitler and deeply virtual Compton scattering processes. For various nuclei, the asymmetries are extracted for both coherent and incoherent-enriched regions, which involve different (combinations of) generalized parton distributions. For both regions, the asymmetries are compared to those for a free proton, and no nuclear-mass dependence is found.

The HERMES collaboration; A. Airapetian

2010-01-22T23:59:59.000Z

163

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

SciTech Connect (OSTI)

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

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

1996-09-15T23:59:59.000Z

164

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

SciTech Connect (OSTI)

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

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

2009-12-01T23:59:59.000Z

165

Optimizing a microwave gas ion source for continuous-flow accelerator mass spectrometry  

SciTech Connect (OSTI)

A 2.45 GHz microwave ion source coupled with a magnesium charge exchange canal (C x C) has been successfully adapted to a large acceptance radiocarbon accelerator mass spectrometry system at the National Ocean Sciences Accelerator Mass Spectrometry (AMS) Facility, Woods Hole Oceanographic Institution. CO{sub 2} samples from various preparation sources are injected into the source through a glass capillary at 370 {mu}l/min. Routine system parameters are about 120-140 {mu}A of negative {sup 12}C current after the C x C, leading to about 400 {sup 14}C counts per second for a modern sample and implying a system efficiency of 0.2%. While these parameters already allow us to perform high-quality AMS analyses on large samples, we are working on ways to improve the output of the ion source regarding emittance and efficiency. Modeling calculations suggest modifications in the extraction triode geometry, shape, and size of the plasma chamber could improve emittance and, hence, ion transport efficiency. Results of experimental tests of these modifications are presented.

Reden, K. F. von; Roberts, M. L.; Burton, J. R.; Beaupre, S. R. [Geology and Geophysics Department, Woods Hole Oceanographic Institution (WHOI), Woods Hole, Massachusetts 02543 (United States)

2012-02-15T23:59:59.000Z

166

Brominated Tyrosine and Polyelectrolyte Multilayer Analysis by Laser Desorption VUV Postionization and Secondary Ion Mass Spectrometry  

SciTech Connect (OSTI)

The small molecular analyte 3,5-dibromotyrosine (Br2Y) and chitosan-alginate polyelectrolyte multilayers (PEM) with and without adsorbed Br2Y were analyzed by laser desorption postionization mass spectrometry (LDPI-MS). LDPI-MS using 7.87 eV laser and tunable 8 ? 12.5 eV synchrotron vacuum ultraviolet (VUV) radiation found that desorption of clusters from Br2Y films allowed detection by?8 eV single photon ionization. Thermal desorption and electronic structure calculations determined the ionization energy of Br2Y to be ~;;8.3?0.1 eV and further indicated that the lower ionization energies of clusters permitted their detection at?8 eV photon energies. However, single photon ionization could only detect Br2Y adsorbed within PEMs when using either higher photon energies or matrix addition to the sample. All samples were also analyzed by 25 keV Bi3 + secondary ion mass spectrometry (SIMS), with the negative ion spectra showing strong parent ion signal which complemented that observed by LDPI-MS. The negative ion SIMS depended strongly on the high electron affinity of this specific analyte and the analyte?s condensed phase environment.

University of Illinois at Chicago; Blaze, Melvin M. T.; Takahashi, Lynelle; Zhou, Jia; Ahmed, Musahid; Gasper, Gerald; Pleticha, F. Douglas; Hanley, Luke

2011-03-14T23:59:59.000Z

167

Dynamics of Ion Beam Stimulated Surface Mass Transport to Nanopores David P. Hoogerheide1  

E-Print Network [OSTI]

Dynamics of Ion Beam Stimulated Surface Mass Transport to Nanopores David P. Hoogerheide1 membrane, from the substrate side, by rastering a 10-nm diameter, 50 keV gallium ion beam produced by a FEI We explore the ion beam-induced dynamics of the formation of large features at the edges of nanopores

168

The effect of cluster formation on mass separation in binary molecular beams  

E-Print Network [OSTI]

The effect of cluster formation on mass separation in binary molecular beams Wei Li,a) M. J composition of a skimmed supersonic binary molecular beam originally consisting of a 20% neon/80% xenon. © 2000 American Institute of Physics. S0021-9606 00 01806-7 I. INTRODUCTION Supersonic molecular beam

Sibener, Steven

169

Analysis of MALDI FT-ICR Mass Spectrometry Data: a Time Series Donald A. Barkauskasa, Scott R. Kronewitterb, Carlito B. Lebrillab, and David M. Rockec  

E-Print Network [OSTI]

Analysis of MALDI FT-ICR Mass Spectrometry Data: a Time Series Approach Donald A. Barkauskasa/ionization Fourier transform ion cyclotron resonance mass spectrometry is a technique for high mass gamma distribution with varying scale parameter but constant shape parameter and exponent. This enables

Rocke, David M.

170

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

SciTech Connect (OSTI)

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

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

2009-12-01T23:59:59.000Z

171

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

E-Print Network [OSTI]

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

American Society for Testing and Materials. Philadelphia

2008-01-01T23:59:59.000Z

172

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

SciTech Connect (OSTI)

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

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

2005-03-01T23:59:59.000Z

173

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

SciTech Connect (OSTI)

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

174

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

SciTech Connect (OSTI)

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

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

1997-06-01T23:59:59.000Z

175

A fast microchannel plate-scintillator detector for velocity map imaging and imaging mass spectrometry  

SciTech Connect (OSTI)

The time resolution achievable using standard position-sensitive ion detectors, consisting of a chevron pair of microchannel plates coupled to a phosphor screen, is primarily limited by the emission lifetime of the phosphor, around 70 ns for the most commonly used P47 phosphor. We demonstrate that poly-para-phenylene laser dyes may be employed extremely effectively as scintillators, exhibiting higher brightness and much shorter decay lifetimes than P47. We provide an extensive characterisation of the properties of such scintillators, with a particular emphasis on applications in velocity-map imaging and microscope-mode imaging mass spectrometry. The most promising of the new scintillators exhibits an electron-to-photon conversion efficiency double that of P47, with an emission lifetime an order of magnitude shorter. The new scintillator screens are vacuum stable and show no signs of signal degradation even over longer periods of operation.

Winter, B.; King, S. J.; Vallance, C., E-mail: claire.vallance@chem.ox.ac.uk [Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Rd, Oxford OX1 3TA (United Kingdom); Brouard, M., E-mail: mark.brouard@chem.ox.ac.uk [Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Rd, Oxford OX1 3QZ (United Kingdom)

2014-02-15T23:59:59.000Z

176

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

SciTech Connect (OSTI)

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

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

2014-02-04T23:59:59.000Z

177

Membrane-Based Emitter for Coupling Microfluidics with Ultrasensitive Nanoelectrospray Ionization-Mass Spectrometry  

SciTech Connect (OSTI)

An integrated poly(dimethylsiloxane) (PDMS) membrane-based microfluidic emitter for high performance nanoelectrospray ionization-mass spectrometry (nanoESI-MS) has been fabricated and evaluated. The ~100-?m-thick emitter was created by cutting a PDMS membrane that protrudes beyond the bulk substrate. The reduced surface area at the emitter enhances the electric field and reduces wetting of the surface by the electrospray solvent. As such, the emitter provides highly stable electrospray at flow rates as low as 10 nL/min, and is compatible with electrospray solvents containing a large organic component (e.g., 90% methanol). This approach enables facile emitter construction, and provides excellent stability, reproducibility and sensitivity, as well as compatibility with multilayer soft lithography.

Sun, Xuefei; Kelly, Ryan T.; Tang, Keqi; Smith, Richard D.

2011-06-09T23:59:59.000Z

178

Molecular Characterization of Organic Aerosols Using Nanospray Desorption/Electrospray Ionization-Mass Spectrometry  

SciTech Connect (OSTI)

Nanospray desorption electrospray ionization (Nano-DESI) combined with high-resolution mass spectrometry (HR/MS) is a promising approach for detailed chemical characterization of atmospheric organic aerosol (OA) collected in laboratory and field experiments. In Nano-DESI analyte is desorbed into a solvent bridge formed between two capillaries and the analysis surface, which enables fast and efficient characterization of OA collected on substrates without special sample preparation. Stable signals achieved using Nano-DESI make it possible to obtain high-quality HR/MS data using only a small amount of material (<10 ng). Furthermore, Nano-DESI enables efficient detection of chemically labile compounds in OA, which is important for understanding chemical aging phenomena.

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

2010-10-01T23:59:59.000Z

179

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

SciTech Connect (OSTI)

Applying Hadamard transform multiplexing to ion mobility separations (IMS) can significantly improve the signal-to-noise ratio and throughput for IMS coupled mass spectrometry (MS) measurements by increasing the ion utilization efficiency. However, it has been determined that both fluctuations in ion intensity as well as spatial shifts in the multiplexed data lower the signal-to-noise ratios and appear as noise in downstream processing of the data. To address this problem, we have developed a novel algorithm that discovers and eliminates data artifacts. The algorithm uses knowledge of the true signal peaks derived from the encoded data and allows for both artifacts and noise to be removed with high confidence, decreasing the likelihood of false identifications in subsequent data processing. The result is that IMS-MS can be applied to increase measurement sensitivity while avoiding artifacts that have previously limited its utility.

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

2014-12-01T23:59:59.000Z

180

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

SciTech Connect (OSTI)

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

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

2011-03-01T23:59:59.000Z

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


181

Laser desorption time-of-flight mass spectrometry of ultraviolet photo-processed ices  

SciTech Connect (OSTI)

A new ultra-high vacuum experiment is described that allows studying photo-induced chemical processes in interstellar ice analogues. MATRI{sup 2}CES - a Mass Analytical Tool to study Reactions in Interstellar ICES applies a new concept by combining laser desorption and time-of-flight mass spectrometry with the ultimate goal to characterize in situ and in real time the solid state evolution of organic compounds upon UV photolysis for astronomically relevant ice mixtures and temperatures. The performance of the experimental setup is demonstrated by the kinetic analysis of the different photoproducts of pure methane (CH{sub 4}) ice at 20 K. A quantitative approach provides formation yields of several new species with up to four carbon atoms. Convincing evidence is found for the formation of even larger species. Typical mass resolutions obtained range from M/?M ?320 to ?400 for CH{sub 4} and argon, respectively. Additional tests show that the typical detection limit (in monolayers) is ?0.02 ML, substantially more sensitive than the regular techniques used to investigate chemical processes in interstellar ices.

Paardekooper, D. M., E-mail: dmpaardekooper@strw.leidenuniv.nl; Bossa, J.-B.; Isokoski, K.; Linnartz, H., E-mail: linnartz@strw.leidenuniv.nl [Raymond and Beverly Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden (Netherlands)

2014-10-15T23:59:59.000Z

182

Laser Desorption Postionization Mass Spectrometry of Antibiotic-Treated Bacterial Biofilms using Tunable Vacuum Ultraviolet Radiation  

SciTech Connect (OSTI)

Laser desorption postionization mass spectrometry (LDPI-MS) with 8.0 ? 12.5 eV vacuum ultraviolet synchrotron radiation is used to single photon ionize antibiotics andextracellular neutrals that are laser desorbed both neat and from intact bacterial biofilms. Neat antibiotics are optimally detected using 10.5 eV LDPI-MS, but can be ionized using 8.0 eV radiation, in agreement with prior work using 7.87 eV LDPI-MS. Tunable vacuum ultraviolet radiation also postionizes laser desorbed neutrals of antibiotics and extracellular material from within intact bacterial biofilms. Different extracellular material is observed by LDPI-MS in response to rifampicin or trimethoprim antibiotic treatment. Once again, 10.5 eV LDPI-MS displays the optimum trade-off between improved sensitivity and minimum fragmentation. Higher energy photons at 12.5 eV produce significant parent ion signal, but fragment intensity and other low mass ions are also enhanced. No matrix is added to enhance desorption, which is performed at peak power densities insufficient to directly produce ions, thus allowing observation of true VUV postionization mass spectra of antibiotic treated biofilms.

Gasper, Gerald L.; Takahashi, Lynelle K.; Zhou, Jia; Ahmed, Musahid; Moore, Jerry F.; Hanley, Luke

2010-08-04T23:59:59.000Z

183

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

SciTech Connect (OSTI)

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

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

2011-06-06T23:59:59.000Z

184

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

SciTech Connect (OSTI)

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

Biegalski, S; Buchholz, B

2009-08-26T23:59:59.000Z

185

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

E-Print Network [OSTI]

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

Balderas, Sara

2005-11-01T23:59:59.000Z

186

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

SciTech Connect (OSTI)

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

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

1993-05-19T23:59:59.000Z

187

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

SciTech Connect (OSTI)

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

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

2011-01-01T23:59:59.000Z

188

Picoelectrospray Ionization Mass Spectrometry Using Narrow-bore Chemically Etched Emitters  

SciTech Connect (OSTI)

Electrospray ionization mass spectrometry (ESI-MS) at flow rates below ~10 nL/min has been only sporadically explored due to difficulty in reproducibly fabricating emitters that can operate at lower flow rates. Here we demonstrate narrow orifice chemically etched emitters for stable electrospray at flow rates as low as 400 pL/min. Depending on the analyte concentration, we observe two types of MS signal response as a function of flow rate. At low concentrations, an optimum flow rate is observed slightly above 1 nL/min, while the signal decreases monotonically with decreasing flow rates at higher concentrations. In spite of lower MS signal, the ion utilization efficiency increases exponentially with decreasing flow rate in all cases. No unimolecular response was observed within this flow rate range during the analysis of an equimolar mixture of peptides, indicating that ionization efficiency is an analyte-dependent characteristic in given experimental conditions. While little to no gain in signal-to-noise was achieved at ultralow flow rates for concentration-limited analyses, experiments consuming the same amount of analyte suggest that mass-limited analyses will benefit strongly from the use of low flow rates and avoiding unnecessary sample dilution. By operating under optimal conditions, consumption of just 500 zmol of sample yielded signal-to-noise ratios ~10 for some peptides. These findings have important implications for the analysis of trace biological samples.

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

2014-01-01T23:59:59.000Z

189

The Effect of Solvent on the Analysis of Secondary Organic Aerosol Using Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

Solvent-analyte reactions in organic aerosol (OA) extracts prepared for analysis by electrospray ionization mass spectrometry (ESI-MS) were examined. Secondary organic aerosol (SOA) produced by ozonation of d-limonene as well as several test organic chemicals with functional groups typical for OA constituents were dissolved and stored in methanol, d3-methanol, acetonitrile, and d3-acetonitrile to investigate the extent and relative rates of reactions between analyte and solvent. High resolution ESI-MS showed that reactions of carbonyls with methanol produce significant amounts of hemiacetals and acetals on time scales ranging from several minutes to several days, with the reaction rates increasing in acidified solutions. Carboxylic acid groups were observed to react with methanol resulting in the formation of esters. In contrast, acetonitrile extracts showed no evidence of reactions with analyte molecules, suggesting that acetonitrile is the preferred solvent for SOA extraction. The use of solvent-analyte reactivity as an analytical chemistry tool for the improved characterization of functional groups in complex organic mixtures was also demonstrated. Direct comparison between ESI mass spectra of the same SOA samples extracted in reactive (methanol) versus non-reactive (acetonitrile) solvents was used to estimate the relative fractions of ketones (?38%), aldehydes (?6%), and carboxylic acids (?55%) in d-limonene SOA.

Bateman, Adam P.; Walser, Maggie L.; Dessiaterik, Yury; Laskin, Julia; Laskin, Alexander; Nizkorodov, Serguei

2008-10-01T23:59:59.000Z

190

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

SciTech Connect (OSTI)

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

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

2009-08-15T23:59:59.000Z

191

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

SciTech Connect (OSTI)

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

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

2007-09-01T23:59:59.000Z

192

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

SciTech Connect (OSTI)

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

193

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

SciTech Connect (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

194

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

195

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

SciTech Connect (OSTI)

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

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

1994-06-15T23:59:59.000Z

196

Measurement of Ultra-Low Potassium Contaminations with Accelerator Mass Spectrometry  

E-Print Network [OSTI]

Levels of trace radiopurity in active detector materials is a subject of major concern in low-background experiments. Among the radio-isotopes, $\\k40$ is one of the most abundant and yet whose signatures are difficult to reject. Procedures were devised to measure trace potassium concentrations in the inorganic salt CsI as well as in organic liquid scintillator (LS) with Accelerator Mass Spectrometry (AMS), giving, respectively, the $\\k40$-contamination levels of $\\sim 10^{-10}$ and $\\sim 10^{-13}$ g/g. Measurement flexibilities and sensitivities are improved over conventional methods. The projected limiting sensitivities if no excess of potassium signals had been observed over background are $8 \\times 10^{-13}$ g/g and $3 \\times 10^{-17}$ g/g for the CsI and LS, respectively. Studies of the LS samples indicate that the radioactive contaminations come mainly in the dye solutes, while the base solvents are orders of magnitude cleaner. The work demonstrate the possibilities of measuring naturally-occurring isotopes with the AMS techniques.

K. J. Dong

2007-05-01T23:59:59.000Z

197

Measurement of Ultra-Low Potassium Contaminations with Accelerator Mass Spectrometry  

E-Print Network [OSTI]

Levels of trace radiopurity in active detector materials is a subject of major concern in low-background experiments. Among the radio-isotopes, $\\k40$ is one of the most abundant and yet whose signatures are difficult to reject. Procedures were devised to measure trace potassium concentrations in the inorganic salt CsI as well as in organic liquid scintillator (LS) with Accelerator Mass Spectrometry (AMS), giving, respectively, the $\\k40$-contamination levels of $\\sim 10^{-10}$ and $\\sim 10^{-13}$ g/g. Measurement flexibilities and sensitivities are improved over conventional methods. The projected limiting sensitivities if no excess of potassium signals had been observed over background are $8 \\times 10^{-13}$ g/g and $3 \\times 10^{-17}$ g/g for the CsI and LS, respectively. Studies of the LS samples indicate that the radioactive contaminations come mainly in the dye solutes, while the base solvents are orders of magnitude cleaner. The work demonstrate the possibilities of measuring naturally-occurring isoto...

Dong, K J

2007-01-01T23:59:59.000Z

198

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

SciTech Connect (OSTI)

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

199

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 o...

Dillmann, I; Heil, M; Käppeler, F; Wallner, A; Forstner, O; Golser, R; Kutschera, W; Priller, A; Steier, P; Mengoni, A; Gallino, R; Paul, M; Vockenhuber, C; 10.1103/PhysRevC.79.065805

2009-01-01T23:59:59.000Z

200

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

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201

Metabolic Profiling Directly from the Petri Dish Using Nanospray Desorption Electrospray Ionization Imaging Mass Spectrometry  

SciTech Connect (OSTI)

Understanding molecular interaction pathways in complex biological systems constitutes a treasure trove of knowledge that might facilitate the specific, chemical manipulation of the countless microbiological systems that occur throughout our world. However, there is a lack of methodologies that allow the direct investigation of chemical gradients and interactions in living biological systems, in real time. Here, we report the use of nanospray desorption electrospray ionization (nanoDESI) imaging mass spectrometry for in vivo metabolic profiling of living bacterial colonies directly from the Petri dish with absolutely no sample preparation needed. Using this technique, we investigated single colonies of Shewanella oneidensis MR-1, Bacillus subtilis 3610, and Streptomyces coelicolor A3(2) as well as a mixed biofilm of S. oneidensis MR-1 and B. subtilis 3610. Data from B. subtilis 3610 and S. coelicolor A3(2) provided a means of validation for the method while data from S. oneidensis MR-1 and the mixed biofilm showed a wide range of compounds that this bacterium uses for the dissimilatory reduction of extracellular metal oxides, including riboflavin, iron-bound heme and heme biosynthetic intermediates, and the siderophore putrebactin.

Watrous, Jeramie D.; Roach, Patrick J.; Heath, Brandi S.; Alexandrov, Theodore; Laskin, Julia; Dorrestein, Pieter C.

2013-11-05T23:59:59.000Z

202

Electrospray Ionization Mass Spectrometry: From Cluster Ions to Toxic metal Ions in Biology  

SciTech Connect (OSTI)

This dissertation focused on using electrospray ionization mass spectrometry to study cluster ions and toxic metal ions in biology. In Chapter 2, it was shown that primary, secondary and quarternary amines exhibit different clustering characteristics under identical instrument conditions. Carbon chain length also played a role in cluster ion formation. In Chapters 3 and 4, the effects of solvent types/ratios and various instrumental parameters on cluster ion formation were examined. It was found that instrument interface design also plays a critical role in the cluster ion distribution seen in the mass spectrum. In Chapter 5, ESI-MS was used to investigate toxic metal binding to the [Gln{sup 11}]-amyloid {beta}-protein fragment (1-16). Pb and Cd bound stronger than Zn, even in the presence of excess Zn. Hg bound weaker than Zn. There are endless options for future work on cluster ions. Any molecule that is poorly ionized in positive ion mode can potentially show an increase in ionization efficiency if an appropriate anion is used to produce a net negative charge. It is possible that drug protein or drug/DNA complexes can also be stabilized by adding counter-ions. This would preserve the solution characteristics of the complex in the gas phase. Once in the gas phase, CID could determine the drug binding location on the biomolecule. There are many research projects regarding toxic metals in biology that have yet to be investigated or even discovered. This is an area of research with an almost endless future because of the changing dynamics of biological systems. What is deemed safe today may show toxic effects in the future. Evolutionary changes in protein structures may render them more susceptible to toxic metal binding. As the understanding of toxicity evolves, so does the demand for new toxic metal research. New instrumentation designs and software make it possible to perform research that could not be done in the past. What was undetectable yesterday will become routine tomorrow.

Nicholas B. Lentz

2007-12-01T23:59:59.000Z

203

Very high resolution saturation spectroscopy of lutetium isotopes via c-w single-frequency laser resonance ionization mass spectrometry  

SciTech Connect (OSTI)

In this paper, we discuss the use of Resonance Ionization Mass Spectrometry (RIMS) to perform isotopically selective saturation spectroscopy of lutetium isotopes. Utilizing this technique, it is shown that accurate measurements of the relative frequencies of hyperfine (HF) components for different isotopes easily can be made without the need for an isotopically enriched sample. The precision with which the HF splitting constants can be determined is estimated to be approx.5 times greater than in previous work.

Fearey, B.L.; Parent, D.C.; Keller, R.A.; Miller, C.M.

1987-01-01T23:59:59.000Z

204

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

SciTech Connect (OSTI)

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

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

2012-01-15T23:59:59.000Z

205

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

SciTech Connect (OSTI)

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

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

2013-08-08T23:59:59.000Z

206

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

SciTech Connect (OSTI)

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

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

2013-10-02T23:59:59.000Z

207

Identification of serum biomarkers for occupational medicamentosa-like dermatitis induced by trichloroethylene using mass spectrometry  

SciTech Connect (OSTI)

Occupational medicamentosa-like dermatitis induced by trichloroethylene (OMLDT) is an autoimmune disease and it has become a serious occupational health hazard. In the present study, we collected fasting blood samples from patients with OMLDT (n = 18) and healthy volunteers (n = 33) to explore serum peptidome patterns. Peptides in sera were purified using weak cation exchange magnetic beads (MB-WCX), and analyzed by matrix-assisted laser desorption ionization time-of-flight-mass spectrometry (MALDI-TOF-MS) and ClinProTools bioinformatics software. The intensities of thirty protein/peptide peaks were significantly different between the healthy control and OMLDT patients. A pattern of three peaks (m/z 2106.3, 2134.5, and 3263.67) was selected for supervised neural network (SNN) model building to separate the OMLDT patients from the healthy controls with a sensitivity of 95.5% and a specificity of 73.8%. Furthermore, two peptide peaks of m/z 4091.61 and 4281.69 were identified as fragments of ATP-binding cassette transporter family A member 12 (ABCA12), and cationic trypsinogen (PRRS1), respectively. Our findings not only show that specific proteomic fingerprints in the sera of OMLDT patients can be served as a differentiated tool of OMLDT patients with high sensitivity and high specificity, but also reveal the novel correlation between OMLDT with ABC transports and PRRS1, which will be of potential value for clinical and mechanistic studies of OMLDT. - Highlights: • Identify 30 differential protein/peptide peaks between OMLDT and healthy control • The test sensitivity and test specificity were 95.5% and 73.8%, respectively. • ABCA12 and PRSS1 were identified as potential biomarkers in OMLDT patients.

Hong, Wen-Xu; Liu, Wei [Key Laboratory of Modern Toxicology of Shenzhen, Medical Key Laboratory of Guangdong Province, Medical Key Laboratory of Health Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055 (China); Zhang, Yanfang [Shenzhen Prevention and Treatment Center for Occupational Disease, Shenzhen 518001 (China); Huang, Peiwu; Yang, Xifei; Ren, Xiaohu; Ye, Jinbo; Huang, Haiyan [Key Laboratory of Modern Toxicology of Shenzhen, Medical Key Laboratory of Guangdong Province, Medical Key Laboratory of Health Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055 (China); Tang, Haiyan [Shenzhen Prevention and Treatment Center for Occupational Disease, Shenzhen 518001 (China); Zhou, Guifeng [Medical School of Hunan Normal University, Changsha 410006 (China); Huang, Xinfeng; Zhuang, Zhixiong [Key Laboratory of Modern Toxicology of Shenzhen, Medical Key Laboratory of Guangdong Province, Medical Key Laboratory of Health Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055 (China); Liu, Jianjun, E-mail: bio-research@hotmail.com [Key Laboratory of Modern Toxicology of Shenzhen, Medical Key Laboratory of Guangdong Province, Medical Key Laboratory of Health Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055 (China)

2013-11-15T23:59:59.000Z

208

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

209

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

SciTech Connect (OSTI)

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

210

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

E-Print Network [OSTI]

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

Vertes, Akos

211

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

SciTech Connect (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

212

Production of pulsed, mass-selected beams of metal and semiconductor clusters  

SciTech Connect (OSTI)

We report on the development of a beam line for mass-selected metal and semiconductor clusters. The cluster source combines the principles of plasma sputtering and gas condensation. Both techniques together allow to produce clusters in a wide size range. With the aid of a time-of-flight system, small clusters (i.e., Cu{sub n}{sup +}, n<100) are selected and pure beams containing only one cluster size are provided. For large clusters (containing several thousands of atoms), a beam with a narrow size distribution is obtained. A 90 deg. quadrupole deviator is used to separate charged clusters from neutral ones.

Kamalou, Omar; Rangama, Jimmy; Ramillon, Jean-Marc; Guinement, Patrick; Huber, Bernd A. [CIMAP, CEA-CNRS-ENSICaen-UCBN, Bv. Henry Becquerel (B.P. 5133), F-14070 Caen Cedex 05 (France)

2008-06-15T23:59:59.000Z

213

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

E-Print Network [OSTI]

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

Schronk, Leonard Royce

1978-01-01T23:59:59.000Z

214

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

E-Print Network [OSTI]

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

May, Jody C.

2010-10-12T23:59:59.000Z

215

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

SciTech Connect (OSTI)

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

Maxwell, S.

2010-07-26T23:59:59.000Z

216

Multiple-ion-beam time-of-flight mass spectrometer Andreas Rohrbacher and Robert E. Continettia)  

E-Print Network [OSTI]

/ionization and the molecular ions of two different proteins myoglobin and lysozyme , created by matrix assisted laser,7 and matrix assisted desorption and ionization MALDI 8­11 have become avail- able to allow the mass the samples with a robot- driven capillary,15 a scanning ion beam,16 or spatial resolu- tion was achieved

Continetti, Robert E.

217

Measurement of Trace I-129 Concentrations in CsI Powder and Organic Liquid Scintillator with Accelerator Mass Spectrometry  

E-Print Network [OSTI]

Levels of trace radiopurity in active detector materials is a subject of major concern in low-background experiments. Procedures were devised to measure trace concentrations of I-129 in the inorganic salt CsI as well as in organic liquid scintillator with Accelerator Mass Spectrometry (AMS) which leads to improvement in sensitivities by several orders of magnitude over other methods. No evidence of their existence in these materials were observed. Limits of scintillator, respectively, were derived.These are the first results in a research program whose goals are to develop techniques to measure trace radioactivity in detector materials by AMS.

K. J. Dong

2005-12-01T23:59:59.000Z

218

Measurement of Trace $^{129}I$ Concentrations in CsI Powder and Organic Liquid Scintillator with Accelerator Mass Spectrometry  

E-Print Network [OSTI]

Levels of trace radiopurity in active detector materials is a subject of major concern in low-background experiments. Procedures were devised to measure trace concentrations of I-129 in the inorganic salt CsI as well as in organic liquid scintillator with Accelerator Mass Spectrometry (AMS) which leads to improvement in sensitivities by several orders of magnitude over other methods. No evidence of their existence in these materials were observed. Limits of scintillator, respectively, were derived.These are the first results in a research program whose goals are to develop techniques to measure trace radioactivity in detector materials by AMS.

Dong, K J

2007-01-01T23:59:59.000Z

219

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

SciTech Connect (OSTI)

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

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

1988-07-01T23:59:59.000Z

220

affinity-purification mass spectrometry: Topics by E-print Network  

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

give comments on precautions Proposed Structure: Nominal Mass (low res.) Accurate Mass (high res.) Atomic Composition*) MSMS (CID) Resolution Polarity: Positive Negative *) Atomic...

Note: This page contains sample records for the topic "beam mass spectrometry" from the National Library of EnergyBeta (NLEBeta).
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221

International Journal of Mass Spectrometry and Ion Processes, 94 (1989) 63-85 Elsevier Science Publishers B.V., Amsterdam -Printed in The Netherlands  

E-Print Network [OSTI]

in the understanding of the formation of mass spectra, among them the unexpectedly high kinetic energy of the laserInternational Journal of Mass Spectrometry and Ion Processes, 94 (1989) 63-85 Elsevier Science, cloud extensions, ion yields, relative sensitivity factors and ion kinetic energy distributions, i

Vertes, Akos

222

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

SciTech Connect (OSTI)

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

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

2009-09-09T23:59:59.000Z

223

Validating mass spectrometry measurements of nuclear materials via a non-contact volume analysis method of ion sputter craters  

SciTech Connect (OSTI)

A combination of secondary ion mass spectrometry, optical profilometry and a statistically-driven algorithm was used to develop a non-contact volume analysis method to validate the useful yields of nuclear materials. The volume analysis methodology was applied to ion sputter craters created in silicon and uranium substrates sputtered by 18.5 keV O- and 6.0 keV Ar+ ions. Sputter yield measurements were determined from the volume calculations and were shown to be comparable to Monte Carlo calculations and previously reported experimental observations. Additionally, the volume calculations were used to determine the useful yields of Si+, SiO+ and SiO2+ ions from the silicon substrate and U+, UO+ and UO2+ ions from the uranium substrate under 18.5 keV O- and 6.0 keV Ar+ ion bombardment. This work represents the first steps toward validating the interlaboratory and cross-platform performance of mass spectrometry for the analysis of nuclear materials.

Willingham, David G.; Naes, Benjamin E.; Fahey, Albert J.

2015-01-01T23:59:59.000Z

224

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

SciTech Connect (OSTI)

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

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

2012-02-07T23:59:59.000Z

225

ORGANIC MASS SPECTROMETRY, VOL. 28, 283-284 (1993) OMS Letters  

E-Print Network [OSTI]

, the collision of this beam with the hydrocarbon, deuterocarbon and fluorocarbon monolayers [see, e.g., Figs l charged benzene on the fluorocarbon surface [Fig. l(b)]. In principle, these ions could also originate

Wysocki, Vicki H.

226

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

E-Print Network [OSTI]

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

Mount, Brianna Jane

2010-01-01T23:59:59.000Z

227

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

SciTech Connect (OSTI)

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

228

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

SciTech Connect (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

229

Distance Restraints from Crosslinking Mass Spectrometry: Mining a Molecular Dynamics Simulation Database to Evaluate Lysine-Lysine Distances  

SciTech Connect (OSTI)

Integrative structural biology models the structures of protein complexes that are intractable by classical structural methods (because of extreme size, dynamics, or heterogeneity) by combining computational structural modeling with data from experimental methods. One such method is chemical cross-linking mass spectrometry (XL-MS), in which cross-linked peptides, derived from a covalently cross-linked protein complex and identified by liquid chromatography-mass spectrometry, pinpoint protein residues close in three-dimensional space. The commonly used lysine-reactive N-hydroxysuccinimide ester reagents disuccinimidylsuberate (DSS) and bis(sulfosuccinimidyl)suberate (BS3) have a linker arm that is 11.4 Ĺ long when fully extended. However, XL-MS studies on proteins of known structure frequently report cross-links that exceed this distance. Typically, a tolerance of ~3 Ĺ is added to the theoretical maximum to account for this observation, with little justification for the value chosen. We used the Dynameomics database, a repository of high-quality molecular dynamics simulations of 807 proteins representative of all protein folds, to investigate the change in lysine-lysine distances resulting from native-state dynamics on the time-scale of tens of nanoseconds. We conclude that observed cross-links are consistent with a protein structure if the distance between cross-linked lysine N? atoms is less than the cross-linker length plus 11.3 Ĺ. For DSS or BS3, this corresponds to a C? to C? distance of 30.4 Ĺ. This analysis provides a theoretical basis for the widespread practice of adding a tolerance to the crosslinker length when comparing XL-MS results to structures, and indicates the appropriate values of an XLMS derived distance constraint to use in structural modeling.

Merkley, Eric D.; Rysavy, Steven; Kahraman, Abdullah; Hafen, Ryan P.; Daggett, Valerie; Adkins, Joshua N.

2014-03-18T23:59:59.000Z

230

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

SciTech Connect (OSTI)

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

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

2014-12-01T23:59:59.000Z

231

Principal ComponentAnalysisof Optical EmissionSpectroscopy and MassSpectrometry:Applicationto Reactive Ion Etch  

E-Print Network [OSTI]

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

Shadmehr, Reza

232

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

233

Qualitative and quantitative analysis of proteolytically digested glycoproteins by mass spectrometry  

E-Print Network [OSTI]

of glycoproteins, and it is particularly useful in the detection of glycosylation present on proteins. Most glycoproteins are prepared for mass spectrometric analysis by performing a protease digestion, followed by either a separation by HPLC or some other...

Rebecchi, Kathryn

2011-05-31T23:59:59.000Z

234

A study of the tropospheric oxidation of volatile organic compounds using chemical ionization mass spectrometry  

E-Print Network [OSTI]

The mechanisms and kinetics of reactions important to the troposphere have been investigated using a high pressure, turbulent, discharge-flow technique coupled to a chemical ionization mass spectrometer. The ability to ...

Broekhuizen, Keith Edward, 1974-

2002-01-01T23:59:59.000Z

235

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

E-Print Network [OSTI]

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

Salcedo, D.

236

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

E-Print Network [OSTI]

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

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

2005-09-15T23:59:59.000Z

237

International Journal of Mass Spectrometry and Zon Processes, 78 (1987) 357-392 Elsevier Science Publishers B.V., Amsterdam -Printed in The Netherlands  

E-Print Network [OSTI]

that significant radial energy transport determines the yields for water ice sputtering at high excitationInternational Journal of Mass Spectrometry and Zon Processes, 78 (1987) 357-392 Elsevier Science, an effective area, and an effective depth, which is determined by the radial dissipation of energy when ions

Johnson, Robert E.

238

International Journal of Mass Spectrometry and Ion Processes, 78 (1987) 237-250 Elsevier Science Publishers B.V., Amsterdam -Printed in The Netherlands  

E-Print Network [OSTI]

of interest with high energy (- 100 MeV) 252Cf fission fragments [l]. This high-energy desorptionInternational Journal of Mass Spectrometry and Ion Processes, 78 (1987) 237-250 Elsevier Science polypeptide. Details of the slow unimolecular decay of high molecular weight multiply protonated polypeptides

Chait, Brian T.

239

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

DOE Patents [OSTI]

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

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

2014-02-04T23:59:59.000Z

240

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

SciTech Connect (OSTI)

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

Timothy B. Onasch

2011-10-20T23:59:59.000Z

Note: This page contains sample records for the topic "beam mass spectrometry" 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

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

SciTech Connect (OSTI)

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

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

2006-05-09T23:59:59.000Z

242

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

SciTech Connect (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

243

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

244

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

SciTech Connect (OSTI)

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

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

2011-01-01T23:59:59.000Z

245

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

SciTech Connect (OSTI)

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

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

2006-12-08T23:59:59.000Z

246

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

SciTech Connect (OSTI)

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

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

2005-08-24T23:59:59.000Z

247

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

SciTech Connect (OSTI)

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

Huh, Chih-An

1987-01-01T23:59:59.000Z

248

Mass Spectrometry Analysis of Proteome-wide Proteolytic Post-translational  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping the Nanoscale Landscape PrintSurveyMary K.Mass

249

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

SciTech Connect (OSTI)

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

Isselhardt, B H

2011-09-06T23:59:59.000Z

250

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

SciTech Connect (OSTI)

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

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

2005-04-03T23:59:59.000Z

251

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

E-Print Network [OSTI]

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

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

252

The effect of ultrafast laser wavelength on ablation properties and implications on sample introduction in inductively coupled plasma mass spectrometry  

SciTech Connect (OSTI)

We investigated the role of femtosecond (fs) laser wavelength on laser ablation (LA) and its relation to laser generated aerosol counts and particle distribution, inductively coupled plasma-mass spectrometry (ICP-MS) signal intensity, detection limits, and elemental fractionation. Four different NIST standard reference materials (610, 613, 615, and 616) were ablated using 400 nm and 800 nm fs laser pulses to study the effect of wavelength on laser ablation rate, accuracy, precision, and fractionation. Our results show that the detection limits are lower for 400 nm laser excitation than 800 nm laser excitation at lower laser energies but approximately equal at higher energies. Ablation threshold was also found to be lower for 400 nm than 800 nm laser excitation. Particle size distributions are very similar for 400 nm and 800 nm wavelengths; however, they differ significantly in counts at similar laser fluence levels. This study concludes that 400 nm LA is more beneficial for sample introduction in ICP-MS, particularly when lower laser energies are to be used for ablation.

LaHaye, N. L.; Harilal, S. S.; Diwakar, P. K.; Hassanein, A. [Center for Materials under Extreme Environment, School of Nuclear Engineering Purdue University, West Lafayette, Indiana 47907 (United States); Kulkarni, P. [Centers for Disease Control and Prevention, National Institute of Occupational Safety and Health, Cincinnati, Ohio 45213 (United States)

2013-07-14T23:59:59.000Z

253

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

SciTech Connect (OSTI)

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

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

2011-11-01T23:59:59.000Z

254

Recommendations for mass spectrometry data quality metrics for open access data(corollary to the Amsterdam principles)  

SciTech Connect (OSTI)

Policies supporting the rapid and open sharing of proteomic data are being implemented by the leading journals in the field. The proteomics community is taking steps to ensure that data are made publicly accessible and are of high quality, a challenging task that requires the development and deployment of methods for measuring and documenting data quality metrics. On September 18, 2010, the U.S. National Cancer Institute (NCI) convened the 'International Workshop on Proteomic Data Quality Metrics' in Sydney, Australia, to identify and address issues facing the development and use of such methods for open access proteomics data. The stakeholders at the workshop enumerated the key principles underlying a framework for data quality assessment in mass spectrometry data that will meet the needs of the search community, journals, funding agencies, and data repositories. Attendees discussed and agreed upon two primary needs for the wide use of quality metrics: (i)an evolving list of comprehensive quality metrics and (ii)standards accompanied by software analytics. Attendees stressed the importance of increased education and training programs to promote reliable protocols in proteomics. This workshop report explores the historic precedents, key discussions, and necessary next steps to enhance the quality of open access data. By agreement, this article is published simultaneously in Proteomics, Proteomics Clinical Applications, Journal of Proteome Research, and Molecular and Cellular Proteomics, as a public service to the research community.The peer review process was a coordinated effort conducted by a panel of referees selected by the journals.

Kingsinger, Christopher R.; Apffel, James; Baker, Mark S.; Bian, Xiaopeng; Borchers, Christoph H.; Bradshaw, Ralph A.; Brusniak, Mi-Youn; Chan, Daniel W.; Deutsch, Eric W.; Domon, Bruno; Gorman, Jeff; Grimm, Rudolf; Hancock, William S.; Hermjakob, Henning; Horn, David; Hunter, Christie; Kolar, Patrik; Kraus, Hans-Joachim; Langen, Hanno; Linding, Rune; Moritz, Robert L.; Omenn, Gilbert S.; Orlando, Ron; Pandey, Akhilesh; Ping, Peipei; Rahbar, Amir; Rivers, Robert; Seymour, Sean L.; Simpson, Richard J.; Slotta, Douglas; Smith, Richard D.; Stein, Stephen E.; Tabb, David L.; Tagle, Danilo; Yates, John R.; Rodriguez, Henry

2011-12-01T23:59:59.000Z

255

Enrichment and Analysis of Nonenzymatically Glycated Peptides: Boronate Affinity Chromatography Coupled with Electron-Transfer Dissociation Mass Spectrometry  

SciTech Connect (OSTI)

Non-enzymatic glycation of peptides and proteins by D-glucose has important implications in the pathogenesis of diabetes mellitus, particularly in the development of diabetic complications. However, no effective high-throughput methods exist for identifying proteins containing this low abundance post-translational modification in bottom-up proteomic studies. In this report, phenylboronate affinity chromatography was used in a two-step enrichment scheme to selectively isolate first glycated proteins and then glycated, tryptic peptides from human serum glycated in vitro. Enriched peptides were subsequently analyzed by alternating electron transfer dissociation (ETD) and collision induced dissociation (CID) tandem mass spectrometry. It was observed that ETD fragmentation mode resulted in a significantly higher number of glycated peptide identifications (87.6% of all identified peptides) versus CID mode (17.0% of all identified peptides), when utilizing dual glycation enrichment on both the protein and peptide level. This study illustrates that phenylboronate affinity chromatography coupled with LC-MS/MS with ETD as the fragmentation mode is an efficient approach for analyses of glycated proteins and can have broad applications in studies of diabetes mellitus.

Zhang, Qibin; Tang, Ning; Brock, Jonathan W.; Mottaz, Heather M.; Ames, Jennifer M.; Baynes, John; Smith, Richard D.; Metz, Thomas O.

2007-06-01T23:59:59.000Z

256

Observation of a small oligonucleotide duplex by electrospray ionization mass spectrometry  

SciTech Connect (OSTI)

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

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

1993-01-27T23:59:59.000Z

257

Radiation environment simulations at the Tevatron, studies of the beam profile and measurement of the Bc meson mass  

SciTech Connect (OSTI)

The description of a computer simulation of the CDF detector at Fermilab and the adjacent accelerator parts is detailed, with MARS calculations of the radiation background in various elements of the model due to the collision of beams and machine-related losses. Three components of beam halo formation are simulated for the determination of the principal source of radiation background in CDF due to beam losses. The effect of a collimator as a protection for the detector is studied. The simulation results are compared with data taken by a CDF group. Studies of a 150 GeV Tevatron proton beam are performed to investigate the transverse diffusion growth and distribution. A technique of collimator scan is used to scrape the beam under various experimental conditions, and computer programs are written for the beam reconstruction. An average beam halo growth speed is given and the potential of beam tail reconstruction using the collimator scan is evaluated. A particle physics analysis is conducted in order to detect the B{sub c} {yields} J/{psi}{pi} decay signal with the CDF Run II detector in 360 pb{sup -1} of data. The cut variables and an optimization method to determine their values are presented along with a criterion for the detection threshold of the signal. The mass of the B{sub c} meson is measured with an evaluation of the significance of the signal.

Nicolas, Ludovic Y.

2005-09-01T23:59:59.000Z

258

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

SciTech Connect (OSTI)

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

Martin, A N

2009-01-27T23:59:59.000Z

259

Spatially resolved chemical imaging of individual atmospheric particles using nanoscale imaging mass spectrometry: Insighs into particle origin and chemistry  

SciTech Connect (OSTI)

Knowledge of the spatially-resolved composition of atmospheric particles is essential for differentiating between their surface versus bulk chemistry, understanding particle reactivity and the potential environmental impact. We demonstrate the application of nanometer-scale secondary ion mass spectrometry (Cameca NanoSIMS 50 ion probe) for 3D chemical imaging of individual atmospheric particles without any sample pre-treatment, such as the sectioning of particles. Use of NanoSIMS depth profile analysis enables elemental mapping of particles with nanometer spatial resolution over a broad of range of particle sizes. We have used this technique to probe spatially resolved composition of ambient particles collected during a field campaign in Mexico City. Particles collected during this campaign have been extensively characterized in the past using other particle analysis techniques and hence offer a unique opportunity for exploring the utility of depth resolved chemical imaging in ambient particle research. 1 Particles examined in this study include those collected during a pollution episode related to urban waste incineration as well as background particles from the same location prior to the episode. Particles from the pollution episode show substantial intra-particle compositional variability typical of particles resulting from multiple emission sources. In contrast, the background particles have relatively homogeneous compositions with enhanced presence of nitrogen, oxygen and chlorine at the particle surface. The observed surface enhancement of nitrogen and oxygen species is consistent with the presence of surface nitrates resulting from gas-particle heterogeneous interactions and is indicative of atmospheric ageing of the particles. The results presented here illustrate 3D characterization of ambient particles for insights into their chemical history.

Ghosal, Sutapa; Weber, Peter K.; Laskin, Alexander

2014-04-21T23:59:59.000Z

260

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

SciTech Connect (OSTI)

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

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

2010-08-20T23:59:59.000Z

Note: This page contains sample records for the topic "beam mass spectrometry" 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 Spectrometry | EMSL  

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

at the cell surface are upregulated within a few hours of purine removal from the media, while other key purine salvage components are upregulated later in the time-course...

262

BIOLOGICAL ANALYSIS Mass Spectrometry  

E-Print Network [OSTI]

Microscope) Analytical Equipment · High Performance Liquid Chromatography · Fast Protein Liquid Chromatography · Gas Chromatography · GC/MS · Elemental Analyser Molecular Biology Equipment · Biorad PCR Machine reactor for scale up studies In-line Particle sizers Rheometers Separation tanks Oscillating column (4m

Greenaway, Alan

263

EMSL - Mass Spectrometry  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to UserProduct:DirectivesSAND2015-21271 7 6 EIA-176Pageenergy

264

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

265

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

SciTech Connect (OSTI)

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

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

1996-12-31T23:59:59.000Z

266

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

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

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

267

Pyrolysis of Organic Molecules Relevant to Combustion as Monitored by Photoionization Time-of-Flight Mass Spectrometry  

E-Print Network [OSTI]

of Small Molecules by Flash Pyrolysis, University ofapproach of coupling flash pyrolysis of the compound ofZhang, Chairperson Flash pyrolysis coupled to molecular beam

Weber, Kevin Howard

2010-01-01T23:59:59.000Z

268

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

SciTech Connect (OSTI)

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

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

2011-01-01T23:59:59.000Z

269

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

SciTech Connect (OSTI)

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

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

2012-07-23T23:59:59.000Z

270

A Perspective on the Maillard Reaction and the Analysis of Protein Glycation by Mass Spectrometry: Probing the Pathogenesis of Chronic Disease  

SciTech Connect (OSTI)

The Maillard reaction, starting from the glycation of protein and progressing to the formation of advanced glycation end-products (AGEs), is implicated in the development of complications of diabetes mellitus, as well as in the pathogenesis of cardiovascular, renal, and neurodegenerative diseases. In this perspective review, we provide on overview on the relevance of the Maillard reaction in the pathogenesis of chronic disease and discuss traditional approaches and recent developments in the analysis of glycated proteins by mass spectrometry. We propose that proteomics approaches, particularly bottom-up proteomics, will play a significant role in analyses of clinical samples leading to the identification of new markers of disease development and progression.

Zhang, Qibin; Ames, Jennifer M.; Smith, Richard D.; Baynes, John; Metz, Thomas O.

2008-12-18T23:59:59.000Z

271

Depth distribution of lithium in oxidized binary Al-Li alloys determined by secondary ion mass spectrometry and neutron depth profiling  

SciTech Connect (OSTI)

Oxidation of binary Al-Li alloys during short exposures at 530 C and long exposures at 200 C was studied with regard to the Li distribution. Secondary ion mass spectrometry (SIMS) and neutron depth profiling (NDP) were used to obtain quantitative Li depth profiles across the surface oxide layer and the underlying alloy. The underlying alloy was depleted in Li as a result of oxidation at 530 and 200 C. The SIMS and NDP results showed good mutual agreement and were used to evaluate the oxide thickness, the Li concentration at the oxide-ally interface, and the mass balance between oxide and alloy. The Li depletion profiles in the alloy were also calculated using the interdiffusion coefficients reported in the literature and compared with the measured profiles; the two profiles differed at 530 C but showed good agreement at 200 C.

Soni, K.K. (Univ. of Chicago, IL (United States)); Williams, D.B. (Lehigh Univ., Bethlehem, PA (United States)); Newbury, D.E.; Chi, P.; Downing, R.G.; Lamaza, G. (National Inst. of Standards and Technology, Gaithersburg, MD (United States))

1993-01-01T23:59:59.000Z

272

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

SciTech Connect (OSTI)

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

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

2007-01-15T23:59:59.000Z

273

HEAVY GOLD CLUSTER BEAMS production and identi cation  

E-Print Network [OSTI]

. This method is based on the acceleration of the clusters to high energy (MeV) and on the measurement, after to select heavy Aun cluster beams for applications at low energy (keV) in mass spectrometry. 1. Introduction, with a multianode detector 7], the number of constituents coming out of the foil. High energy clusters, accelerated

Boyer, Edmond

274

High-resolution time-of-flight mass spectrometry fingerprinting of metabolites from cecum and distal colon contents of rats fed resistant starch  

SciTech Connect (OSTI)

Time-of-flight mass spectrometry along with statistical analysis was utilized to study metabolic profiles among rats fed resistant starch (RS) diets. Fischer 344 rats were fed four starch diets consisting of 55 % (w/w, dbs) starch. A control starch diet consisting of corn starch was compared against three RS diets. The RS diets were high-amylose corn starch (HA7), HA7 chemically modified with octenyl succinic anhydride, and stearic-acid-complexed HA7 starch. A subgroup received antibiotic treatment to determine if perturbations in the gut microbiome were long lasting. A second subgroup was treated with azoxymethane (AOM), a carcinogen. At the end of the 8-week study, cecal and distal colon content samples were collected from the sacrificed rats. Metabolites were extracted from cecal and distal colon samples into acetonitrile. The extracts were then analyzed on an accurate-mass time-of-flight mass spectrometer to obtain their metabolic profile. The data were analyzed using partial least-squares discriminant analysis (PLS-DA). The PLS-DA analysis utilized a training set and verification set to classify samples within diet and treatment groups. PLS-DA could reliably differentiate the diet treatments for both cecal and distal colon samples. The PLS-DA analyses of the antibiotic and no antibiotic-treated subgroups were well classified for cecal samples and modestly separated for distal colon samples. PLS-DA analysis had limited success separating distal colon samples for rats given AOM from those not treated; the cecal samples from AOM had very poor classification. Mass spectrometry profiling coupled with PLS-DA can readily classify metabolite differences among rats given RS diets.

Anderson, Timothy J. [Ames Laboratory; Jones, Roger W. [Ames Laboratory; Ai, Yongfeng [Iowa State University; Houk, Robert S. [Ames Laboratory; Jane, Jay-lin [Iowa State University; Zhao, Yinsheng [Iowa State University; Birt, Diane F. [Iowa State University; McClelland, John F. [Ames Laboratory

2013-12-04T23:59:59.000Z

275

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

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

276

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

E-Print Network [OSTI]

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

Lemieux, Jessy Mario

2013-01-01T23:59:59.000Z

277

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

SciTech Connect (OSTI)

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

278

Detection and quantitation of benzo(a)pyrene-derived DNA adducts in mouse liver by liquid chromatography - tandem mass spectrometry: comparison with P-32-postlabeling  

SciTech Connect (OSTI)

The polycyclic aromatic hydrocarbon, benzo(a)pyrene (B(a)P) is a proven animal carcinogen that is potentially carcinogenic to humans. B( a)P is an ubiquitous environmental pollutant and is also present in tobacco smoke, coal tar, automobile exhaust emissions, and charred food. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using electrospray ionization and selected reaction monitoring (SRM) has been developed for the detection of 10-(deoxyguanosin-N{sub 2}-yl)-7,8,9-trihydroxy-7,8,9,10- tetrahydrobenzo(a)pyrene (B(a)PDE-N{sub 2}dG) adducts formed in DNA following the metabolic activation of B(a)P to benzo(a) pyrene-7,8-dihydrodiol-9,10-epoxide (B(a)PDE).

Singh, R.; Gaskell, M.; Le Pla, R.C.; Kaur, B.; Azim-Araghi, A.; Roach, J.; Koukouves, G.; Souliotis, V.L.; Kyrtopoulos, S.A.; Farmer, P.B. [University of Leicester, Leicester (United Kingdom)

2006-06-19T23:59:59.000Z

279

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

SciTech Connect (OSTI)

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

280

Ion mass spectrometry investigations of the discharge during reactive high power pulsed and direct current magnetron sputtering of carbon in Ar and Ar/N{sub 2}  

SciTech Connect (OSTI)

Ion mass spectrometry was used to investigate discharges formed during high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (DCMS) of a graphite target in Ar and Ar/N{sub 2} ambient. Ion energy distribution functions (IEDFs) were recorded in time-averaged and time-resolved mode for Ar{sup +}, C{sup +}, N{sub 2}{sup +}, N{sup +}, and C{sub x}N{sub y}{sup +} ions. An increase of N{sub 2} in the sputter gas (keeping the deposition pressure, pulse width, pulse frequency, and pulse energy constant) results for the HiPIMS discharge in a significant increase in C{sup +}, N{sup +}, and CN{sup +} ion energies. Ar{sup +}, N{sub 2}{sup +}, and C{sub 2}N{sup +} ion energies, in turn, did not considerably vary with the changes in working gas composition. The HiPIMS process showed higher ion energies and fluxes, particularly for C{sup +} ions, compared to DCMS. The time evolution of the plasma species was analyzed for HiPIMS and revealed the sequential arrival of working gas ions, ions ejected from the target, and later during the pulse-on time molecular ions, in particular CN{sup +} and C{sub 2}N{sup +}. The formation of fullerene-like structured CN{sub x} thin films for both modes of magnetron sputtering is explained by ion mass-spectrometry results and demonstrated by transmission electron microscopy as well as diffraction.

Schmidt, S.; Greczynski, G.; Jensen, J.; Hultman, L. [Thin Film Physics Div., Department of Physics (IFM), Linkoeping University, SE-581 83 (Sweden); Czigany, Zs. [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Konkoly Thege Miklos ut 29-33. H-1121 Budapest (Hungary)

2012-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam mass spectrometry" 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

Improved resolution of hydrocarbon structures and constitutional isomers in complex mixtures using Gas Chromatography-Vacuum Ultraviolet-Mass Spectrometry (GC-VUV-MS)  

SciTech Connect (OSTI)

Understanding the composition of complex hydrocarbon mixtures is important for environmental studies in a variety of fields, but many prevalent compounds cannot be confidently identified using traditional gas chromatography-mass spectrometry (GC-MS) techniques. This work uses vacuum-ultraviolet (VUV) ionization to elucidate the structures of a traditionally"unresolved complex mixture" by separating components by GC retention time, tR, and mass-to-charge ratio, m/Q, which are used to determine carbon number, NC, and the number of rings and double bonds, NDBE. Constitutional isomers are resolved based on tR, enabling the most complete quantitative analysis to date of structural isomers in an environmentally-relevant hydrocarbon mixture. Unknown compounds are classified in this work by carbon number, degree of saturation, presence of rings, and degree of branching, providing structural constraints. The capabilities of this analysis are explored using diesel fuel, in which constitutional isomer distribution patterns are shown to be reproducible between carbon numbers and follow predictable rules. Nearly half of the aliphatic hydrocarbon mass is shown to be branched, suggesting branching is more important in diesel fuel than previously shown. The classification of unknown hydrocarbons and the resolution of constitutional isomers significantly improves resolution capabilities for any complex hydrocarbon mixture.

Aerosol Dynamics Inc; Aerodyne Research, Inc.,; Tofwerk AG, Thun; Isaacman, Gabriel; Wilson, Kevin R.; Chan, Arthur W. H.; Worton, David R.; Kimmel, Joel R.; Nah, Theodora; Hohaus, Thorsten; Gonin, Marc; Kroll, Jesse H.; Worsnop, Doug R.; Goldstein, Allen H.

2011-09-13T23:59:59.000Z

282

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

SciTech Connect (OSTI)

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

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

1989-12-01T23:59:59.000Z

283

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

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

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

284

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 (OSTI)

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

285

A precise Higgs mass measurement at the ILC and test beam data analyses  

E-Print Network [OSTI]

for the Higgs boson mass measurement, while the cross section could be measured to 5%; if we make some assumptions about the Higgs boson's decay, for example a Standard Model Higgs boson with a dominant invisible

Boyer, Edmond

286

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

SciTech Connect (OSTI)

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

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

2010-01-01T23:59:59.000Z

287

PILOT_PROTEIN: Identification of Unmodified and Modified Proteins via High-Resolution Mass Spectrometry and Mixed-Integer Linear  

E-Print Network [OSTI]

accuracy with a lower false positive rate. All materials are freely available to the scientific community and protein identification and can help reduce the number of false positive resulPILOT_PROTEIN: Identification of Unmodified and Modified Proteins via High-Resolution Mass

Shorter, James

288

Molecular characterization of organic aerosol using nanospray desorption/ electrospray ionization mass spectrometry: CalNex 2010 field study  

E-Print Network [OSTI]

Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, USA c Chemical and Materials Sciences molecular species were detected in the mass range of 50e400 m/z using positive mode ESI of aerosol samples in the 0.18e0.32 mm size range. Our analysis focused on identification of two main groups: compounds

Goldstein, Allen

289

and Ion Processes ELSEVIER International Journal of Mass Spectrometry and lon Processes 167/168 (1997) 637-647  

E-Print Network [OSTI]

/168 (1997) 637-647 Microsolvation of the ammonium ion in argon: infrared spectra of NH --Arn complexes (n Received 25 November 1996; accepted 2 June 1997 Abstract Infrared spectra of mass selected NH~-Ar, (n = 1 of the tetrahedral monomer. © 1997 Elsevier Science B.V. © 1997 Elsevier Science B.V. Keywords: Ab initio studies

Nizkorodov, Sergey

290

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

E-Print Network [OSTI]

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

Zandstra, Peter W.

291

Size-selected 2, 5, and 10 nm gold nanoparticles for laser desorption/ionization mass spectrometry  

E-Print Network [OSTI]

, as subtle changes in the solution environment can result in subsequent changes in the mass spectra. A thorough evaluation of the parameters that affect desorption/ionization of peptides is presented here, and these parameters include: (i) AuNP-to...

Stumpo, Katherine Anne

2009-05-15T23:59:59.000Z

292

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

SciTech Connect (OSTI)

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

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

2012-07-02T23:59:59.000Z

293

Accelerated Analyte Uptake on Single Beads in Microliter-scale Batch Separations using Acoustic Streaming: Plutonium Uptake by Anion Exchange for Analysis by Mass Spectrometry  

SciTech Connect (OSTI)

The use of acoustic streaming as a non-contact mixing platform to accelerate mass transport-limited diffusion processes in small volume heterogeneous reactions has been investigated. Single bead anion exchange of plutonium at nanomolar and sub-picomolar concentrations in 20 microliter liquid volumes was used to demonstrate the effect of acoustic mixing. Pu uptake rates on individual ~760 micrometer diameter AG 1x4 anion exchange resin beads were determined using acoustic mixing and compared with Pu uptake rates achieved by static diffusion alone. An 82 MHz surface acoustic wave (SAW) device was placed in contact with the underside of a 384-well microplate containing flat-bottomed semiconical wells. Acoustic energy was coupled into the solution in the well, inducing acoustic streaming. Pu uptake rates were determined by the plutonium remaining in solution after specific elapsed time intervals, using liquid scintillation counting (LSC) for nanomolar concentrations and thermal ionization mass spectrometry (TIMS) analysis for the sub-picomolar concentration experiments. It was found that this small batch uptake reaction could be accelerated by a factor of about five-fold or more, depending on the acoustic power applied.

Paxton, Walter F.; O'Hara, Matthew J.; Peper, Shane M.; Petersen, Steven L.; Grate, Jay W.

2008-06-01T23:59:59.000Z

294

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

E-Print Network [OSTI]

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

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

295

Molecular Characterization of Organosulfates in Organic Aerosols from Shanghai and Los Angeles Urban Areas by Nanospray-Desorption Electrospray Ionization High-Resolution Mass Spectrometry  

SciTech Connect (OSTI)

Aerosol samples collected in the urban areas of Shanghai and Los Angeles were analyzed by nanospray-desorption electrospray ionization mass spectrometry (nano-DESI MS) with high mass resolution (m/?m=100,000). Solvent mixtures of acetonitrile/water and acetonitrile/toluene were used to extract and ionize polar and non-polar compounds, respectively. A diverse mixture of oxygenated hydrocarbons, organosulfates, organonitrates, and organics with reduced nitrogen were detected in the Los Angeles sample. Majority of the organics in the Shanghai sample were detected as organosulfates. The dominant organosulfates in the two samples have distinctly different molecular characteristics. Specifically, organosulfates in the Los Angeles sample were dominated by isoprene- or monoterpene-derived products, while organosulfates of yet unknown origin in the Shanghai sample had distinctive characteristics of long aliphatic carbon chains and low degree of oxidation and unsaturation. The use of acetonitrile/toluene solvent facilitated identification of this type of organosulfates, suggesting they could be missed in previous studies relying on sample extraction using common polar solvents. The high molecular weight and low degree of unsaturation and oxidization of the organosulfates detected in the Shanghai sample suggest that they may act as surfactants, and plausibly affect the surface tension and hygroscopicity of the atmospheric particulate matter. We propose that direct esterification of carbonyl or hydroxyl compounds by sulfates or sulfuric acid in liquid phase could be the formation pathway of these special organosulfates. Long-chain alkanes from vehicle emissions might be their precursors.

Tao, Shikang; Lu, Xiaohui; Levac, Nicole A.; Bateman, Adam P.; Nguyen, Tran B.; Bones, David L.; Nizkorodov, Sergey; Laskin, Julia; Laskin, Alexander; Yang, Xin

2014-08-21T23:59:59.000Z

296

Charge and frequency resolved isochronous mass spectrometry in storage rings: First direct mass measurement of the short-lived neutron-deficient $^{51}$Co nuclide  

E-Print Network [OSTI]

Revolution frequency measurements of individual ions in storage rings require sophisticated timing detectors. One of common approaches for such detectors is the detection of secondary electrons released from a thin foil due to penetration of the stored ions. A new method based on the analysis of intensities of secondary electrons was developed which enables determination of the charge of each ion simultaneously with the measurement of its revolution frequency. Although the mass-over-charge ratios of $^{51}$Co$^{27+}$ and $^{34}$Ar$^{18+}$ ions are almost identical, and therefore, the ions can not be resolved in a storage ring, by applying the new method the mass excess of the short-lived $^{51}$Co is determined for the first time to be ME($^{51}$Co)=-27342(48) keV. Shell-model calculations in the $fp$-shell nuclei compared to the new data indicate the need to include isospin-nonconserving forces.

P. Shuai; H. S. Xu; X. L. Tu; Y. H. Zhang; B. H. Sun; Yu. A. Litvinov; X. L. Yan; K. Blaum; M. Wang; X. H. Zhou; J. J. He; Y. Sun; K. Kaneko; Y. J. Yuan; J. W. Xia; J. C. Yang; G. Audi; X. C. Chen; G. B. Jia; Z. G. Hu; X. W. Ma; R. S. Mao; B. Mei; Z. Y. Sun; S. T. Wang; G. Q. Xiao; X. Xu; T. Yamaguchi; Y. Yamaguchi; Y. D. Zang; H. W. Zhao; T. C. Zhao; W. Zhang; W. L. Zhan

2014-04-08T23:59:59.000Z

297

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

E-Print Network [OSTI]

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

American Society for Testing and Materials. Philadelphia

2005-01-01T23:59:59.000Z

298

Identification of protein-protein interaction and topologies in living cells by chemical cross-linking and mass spectrometry  

SciTech Connect (OSTI)

Current chemical cross-linking methods are commonly employed for mapping sites of interaction and three-dimensional structure in purified, known protein complexes. When applied in vivo in combination of co-immunoprecipitation methods, information on the sites of interaction between proteins are unattainable due to overwhelming sample complexity. We present results from a novel cross-linking strategy that allow simultaneous protein-protein interaction and surface topology measurement in vivo without any prior knowledge of the system. The strategy consists of: (i) cross-linking reaction: intact cell labeling with protein interaction reporters (PIRs); (ii) two-stage mass spectrometric analysis: stage 1 identification of PIR-labeled proteins and construction of a restricted database by 2D-LC/MS/MS; and stage 2 analysis of PIR-labeled peptides by multiplexed LC/FTICR-MS; (iii) data analysis: identification of cross-linked peptides and proteins of origin using accurate mass and other constraints. This strategy was applied to Shewanella oneidensis MR-1 bacterial cells and successfully identified a protein-protein interaction between SecA and a small outer membrane lipoprotein as well as their sites of interaction in vivo.

Zhang, Haizhen; Tang, Xiaoting; Munske, Gerhard R.; Tolic, Nikola; Anderson, Gordon A.; Bruce, James E.

2008-10-20T23:59:59.000Z

299

Identification of Protein-Protein Interactions and Topologies in Living Cells with Chemical Cross-linking and Mass Spectrometry  

SciTech Connect (OSTI)

We present results from a novel strategy that enables concurrent identification of protein-protein interactions and topologies in living cells without specific antibodies or genetic manipulations for immuno/affinity purifications. The strategy consists of: (i) chemical cross-linking reaction: intact cell labeling with a novel class of chemical cross-linkers, protein interaction reporters (PIRs); (ii) two-stage mass spectrometric analysis: stage 1 identification of PIR-labeled proteins and construction of a restricted database by 2D-LC/MS/MS; and stage 2 analysis of PIR-labeled peptides by multiplexed LC/FTICR-MS; (iii) data analysis: identification of cross-linked peptides and proteins of origin using accurate mass and other constraints. The primary advantage of the PIR approach and distinction from current technology is that protein interactions together with topologies are detected in native biological systems by stabilizing protein complexes with new covalent bonds while the proteins are present in the original cellular environment. Thus, weak or transient interactions or interactions that require properly folded, localized, or membrane-bound proteins can be labeled and identified through the PIR approach. This strategy was applied to S. oneidensis bacterial cells and initial studies resulted in identification of a set of protein-protein interactions and their contact/binding regions. Furthermore, most identified interactions involved membrane proteins, suggesting the PIR approach is particularly suited for studies of membrane protein-protein interactions, an area under-represented with current widely-used approaches.

Zhang, Haizhen; Tang, Xiaoting; Munske, Gerhard R.; Tolic, Nikola; Anderson, Gordon A.; Bruce, James E.

2009-03-01T23:59:59.000Z

300

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

SciTech Connect (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

Note: This page contains sample records for the topic "beam mass spectrometry" 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

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

SciTech Connect (OSTI)

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

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

1999-01-15T23:59:59.000Z

302

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

SciTech Connect (OSTI)

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

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

2013-02-01T23:59:59.000Z

303

Gadolinium speciation with Tetradentate, N-donor extractants for minor actinide/lanthanide separation: an XRD, mass spectrometry and EPR study  

SciTech Connect (OSTI)

The hydrophobic organic molecules CyMe{sub 4}-BTPhen (1) and CyMe{sub 4}-BTBP (2) have been developed and tuned over many years to be able to separate the trivalent actinides from the trivalent lanthanides (Ln) selectively in bi-phasic solvent extraction processes for the separation of the long-lived radio-toxic minor actinides from spent nuclear fuel. The ability of these N-donor ligands to perform this separation is poorly understood, as is their speciation with the metal ions when extracted into the organic phase. Our previous work has shown Ln{sup 3+} speciation to be largely 1:2 Ln:L in nature with another small molecule, either water or nitrate, occupying a cavity between the tetradentate bound N-donor ligands. The identity of the small molecule changes across the lanthanide series, and here we continue investigations into this speciation. Complexes of these N-donor ligands with Gd{sup 3+} have been synthesised and characterised by X-ray crystallography, mass spectrometry and EPR spectroscopy. We show that the N-donor ligands have no effect on the electronic configuration of Gd{sup 3+} and that the lanthanide contraction with the steric rigidity of the N-donor ligand appears to determine the size of the cavity between the coordinated ligands. This in turn appears to control the identity of the small molecule on the ninth site in the 1:2 Gd:L species. (authors)

Whittaker, D.M. [School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Sharrad, C.A. [School of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Research Centre for Radwaste and Decommissioning, Dalton Nuclear Institute, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Sproules, S. [Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2013-07-01T23:59:59.000Z

304

Analysis of Nitro-Polycyclic Aromatic Hydrocarbons in Conventional Diesel and Fischer--Tropsch Diesel Fuel Emissions Using Electron Monochromator-Mass Spectrometry  

SciTech Connect (OSTI)

The presence of nitro-polycyclic aromatic hydrocarbons (NPAHs) in diesel fuel emissions has been studied for a number of years predominantly because of their contribution to the overall health and environmental risks associated with these emissions. Electron monochromator-mass spectrometry (EM-MS) is a highly selective and sensitive method for detection of NPAHs in complex matrixes, such as diesel emissions. Here, EM-MS was used to compare the levels of NPAHs in fuel emissions from conventional (petroleum) diesel, ultra-low sulfur/low-aromatic content diesel, Fischer-Tropsch synthetic diesel, and conventional diesel/synthetic diesel blend. The largest quantities of NPAHs were detected in the conventional diesel fuel emissions, while the ultra-low sulfur diesel and synthetic diesel fuel demonstrated a more than 50% reduction of NPAH quantities when compared to the conventional diesel fuel emissions. The emissions from the blend of conventional diesel with 30% synthetic diesel fuel also demonstrated a more than 30% reduction of the NPAH content when compared to the conventional diesel fuel emissions. In addition, a correlation was made between the aromatic content of the different fuel types and NPAH quantities and between the nitrogen oxides emissions from the different fuel types and NPAH quantities. The EM-MS system demonstrated high selectivity and sensitivity for detection of the NPAHs in the emissions with minimal sample cleanup required.

Havey, C. D.; McCormick, R. L.; Hayes, R. R.; Dane, A. J.; Voorhees, K. J.

2006-01-01T23:59:59.000Z

305

Probing Molecular Associations of Field-Collected and Laboratory-Generated SOA with Nano-DESI High-Resolution Mass Spectrometry  

SciTech Connect (OSTI)

Aerosol samples from the 2010 CalNex field study in Bakersfield (BF) and Los Angeles (LA) were analyzed using positive mode nanospray-desorption electrospray ionization mass spectrometry (nano-DESI-MS). Secondary organic aerosol (SOA) produced in a photochemical chamber by photooxidation of diesel (DSL) fuel and isoprene (ISO) under humid, high-NOx conditions, was analyzed for comparison. Three groups of organic compounds with zero, one, or two nitrogen atoms in their molecular formulas (0N, 1N, 2N) were compared in detail. The composition of ambient SOA exhibited greater overlap with DSL than with ISO. The overlap of the chamber experiments with the BF data was relatively consistent throughout the day while the overlap with LA data increased significantly in the noon-6pm sample, consistent with the SOA plume arriving from downtown Los Angeles. BF samples were more oxidized, contained more organic nitrogen, and had more overlap with the chamber data compared to LA samples. The addition of gaseous ammonia (NH3) to the DSL experiment was necessary to generate many of the 2N compounds observed in BF. This analysis demonstrates that DSL and ISO were important sources but cannot account for all of the observed ambient compounds indicating that other sources of organics were also likely important.

O'Brien, Rachel E.; Nguyen, Tran B.; Laskin, Alexander; Laskin, Julia; Hayes, Patrick L.; Liu, Shang; Jimenez, Jose L.; Russell, Lynn M.; Nizkorodov, Sergey; Goldstein, Allen H.

2013-01-30T23:59:59.000Z

306

Studies of the combustion of coal/refuse derived fuels using thermogravimetric-Fourier transform infrared-mass spectrometry  

SciTech Connect (OSTI)

The materials used in this project included two bituminous coals, a medium molecular weight PVC resin, cellulose, and shredded newspaper. Analytical data for the samples are given. A TA Instruments Model 951 Thermogravimetric Analyzer (TG) interfaced to a Perkin Elmer 1650 Fourier Transform Infrared Spectrometer (FTIR) was used in this study. The horizontal quartz furnace of the TG was connected to the 10 cm gas cell of the FTIR using an insulated teflon tube heated to a temperature of 150{degrees}C. The TG was also interfaced to a VG Thermolab Mass Spectrometer (MS) using a fused silica capillary sampling tube heated to approximately 170{degrees}C. A teflon splitter divides the gases from the TG into two parts, one to the FTIR ({approximately}95%), and the other to the MS ({approximately}5%). A schematic of the TG-FTIR-MS system, is presented. In the TG experiments, all samples ({approximately}300 mg each) were heated in air (50 ML/min) at a rate of 10{degrees}C/min to 700{degrees}C. The spectra and profiles of gaseous species evolving from the TG system were recorded and analyzed by the TGA-FTIR-MS analytical system. The results of the experiments are given.

Lu, H.; Li, J.; Lloyd, W.G. [and others

1995-08-01T23:59:59.000Z

307

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

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

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

308

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

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

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

309

E-Print Network 3.0 - alpha spectrometry 232u Sample Search Results  

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

for thermal ionization mass spectrometry (TIMS) and 800 mg for alpha spectrom- etry. Uranium-thorium TIMS... . Alpha spectrometry was performed at the University of Iowa....

310

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

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

311

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

SciTech Connect (OSTI)

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

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

2014-12-14T23:59:59.000Z

312

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

SciTech Connect (OSTI)

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

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

2013-10-15T23:59:59.000Z

313

Rapid and sensitive gas chromatography ion-trap mass spectrometry method for the determination of tobacco specific N-nitrosamines in secondhand smoke  

SciTech Connect (OSTI)

Tobacco-specific nitrosamines (TSNAs) are some of the most potent carcinogens in tobacco and cigarette smoke. Accurate quantification of these chemicals is needed to help assess public health risks. We developed and validated a specific and sensitive method to measure four TSNAs in both the gas- and particle-phase of secondhand smoke (SHS) using gas chromatography and ion-trap tandem mass spectrometry,. A smoking machine in an 18-m3 room-sized chamber generated relevant concentrations of SHS that were actively sampled on Teflon coated fiber glass (TCFG) filters, and passively sampled on cellulose substrates. A simple solid-liquid extraction protocol using methanol as solvent was successfully applied to both filters with high recoveries ranging from 85 to 115percent. Tandem MS parameters were optimized to obtain the best sensitivity in terms of signal to-noise ratio (S/N) for the target compounds. For each TSNA, the major fragmentation pathways as well as ion structures were elucidated and compared with previously published data. The method showed excellent performances with a linear dynamic range between 2 and 1000 ng mL-1, low detection limits (S/N> 3) of 30-300 pg.ml-1 and precision with experimental errors below 10percent for all compounds. Moreover, no interfering peaks were observed indicating a high selectivity of MS/MS without the need for a sample clean up step. The sampling and analysis method provides a sensitive and accurate tool to detect and quantify traces of TSNA in SHS polluted indoor environments.

SLEIMAN, Mohamad; MADDALENA, Randy L.; GUNDEL, Lara A.; DESTAILLATS, Hugo

2009-07-01T23:59:59.000Z

314

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

SciTech Connect (OSTI)

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

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

2014-01-14T23:59:59.000Z

315

Sandia National Laboratories: mass spectrometry  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1developmentturbine bladelifetime is the cumulative time underpower measurementmass

316

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

SciTech Connect (OSTI)

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

317

Calculation of Transactinide Homolog Isotope Production Reactions Possible with the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory  

SciTech Connect (OSTI)

The LLNL heavy element group has been investigating the chemical properties of the heaviest elements over the past several years. The properties of the transactinides (elements with Z > 103) are often unknown due to their low production rates and short half-lives, which require lengthy cyclotron irradiations in order to make enough atoms for statistically significant evaluations of their chemistry. In addition, automated chemical methods are often required to perform consistent and rapid chemical separations on the order of minutes for the duration of the experiment, which can last from weeks to months. Separation methods can include extraction chromatography, liquid-liquid extraction, or gas-phase chromatography. Before a lengthy transactinide experiment can be performed at an accelerator, a large amount of preparatory work must be done both to ensure the successful application of the chosen chemical system to the transactinide chemistry problem being addressed, and to evaluate the behavior of the lighter elemental homologs in the same chemical system. Since transactinide chemistry is literally performed on one single atom, its chemical properties cannot be determined from bulk chemical matrices, but instead must be inferred from the behavior of the lighter elements that occur in its chemical group and in those of its neighboring elements. By first studying the lighter group homologs in a particular chemical system, when the same system is applied to the transactinide element under investigation, its decay properties can be directly compared to those of the homologues, thereby allowing an inference of its own chemistry. The Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory (LLNL) includes a 1 MV Tandem accelerator, capable of accelerating light ions such as protons to energies of roughly 15 MeV. By using the CAMS beamline, tracers of transactinide homolog elements can be produced both for development of chemical systems and for evaluation of homolog chemical properties. CAMS also offers an environment for testing these systems 'online' by incorporating automated chemical systems into the beamline so that tracers can be created, transported, and chemically separated all on the shorter timescales required for transactinide experiments. Even though CAMS is limited in the types and energies of ions they can accelerate, there are still a wide variety of reactions that can be performed there with commercially available target materials. The half-lives of these isotopes vary over a range that could be used for both online chemistry (where shorter half-lives are required) and benchtop tracers studies (where longer lived isotopes are preferred). In this document, they present a summary of tracer production reactions that could be performed at CAMS, specifically for online, automated chemical studies. They are from chemical groups four through seven, 13, and 14, which would be appropriate for studies of elements 104-107, 113, and 114. Reactions were selected that had (a) commercially available target material, (b) half-lives long enough for transport from a target chamber to an automated chemistry system, and (c) cross-sections at CAMS available projectile energies that were large enough to produce enough atoms to result in a statistically relevant signal after losses for transport and chemistry were considered. In addition, the resulting product atoms had to decay with an observable gamma-ray using standard Ge gamma-ray detectors. The table includes calculations performed for both metal targets and their corresponding oxides.

Moody, K J; Shaughnessy, D A; Gostic, J M

2011-11-29T23:59:59.000Z

318

Heavy ion Rutherford Backscattering Spectrometry (HIRBS) for the near surface characterization of electronic materials  

SciTech Connect (OSTI)

The use of heavy ion projectiles for Rutherford Backscattering Spectrometry (RBS) provides several potential advantages over conventional RBS with /sup 4/He beams. Among these advantages are the improved mass resolution for heavy elements (>50 amu) and the increased accessible depth of analysis. A series of experiments using 20-MeV /sup 16/O beam backscattered from a variety of targets was performed in order to examine the potential advantages of heavy ion RBS in the near-surface characterization of semiconductors with masses >50 amu. Important questions such as mass resolution, depth resolution, isotopic effects, absolute sensitivity and minimum detectable limit of impurities were investigated. Ion implantations and multiple layered structures on GaAs substrates as well as metal germanide systems were studied. The development of the method in conjunction with the channeling technique is also discussed.

Yu, K.M.

1984-12-01T23:59:59.000Z

319

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

SciTech Connect (OSTI)

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

Messerly, Joshua D.

2008-08-26T23:59:59.000Z

320

High Mass Accuracy and High Mass Resolving Power FT-ICR Secondary...  

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

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

Note: This page contains sample records for the topic "beam mass spectrometry" 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

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

SciTech Connect (OSTI)

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

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

2014-01-31T23:59:59.000Z

322

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

323

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.

324

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  

SciTech Connect (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 Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and complementary instrumentation. Mass concentrations, diurnal cycles, and size distributions of inorganic and organic species are similar to results from the CENICA supersite in April 2003 with organic aerosol (OA) comprising about half of the fine PM mass. Positive Matrix Factorization (PMF) analysis of the high resolution OA spectra identifies three major components: chemically-reduced urban primary emissions (hydrocarbon-like OA, HOA), oxygenated OA (OOA, mostly secondary OA or SOA), and biomass burning OA (BBOA) that correlates with levoglucosan and acetonitrile. BBOA includes several very large plumes from regional fires and likely also some refuse burning.

Aiken, Allison; Salcedo, D.; Cubison, Michael J.; Huffman, J.; DeCarlo, Peter; Ulbrich, Ingrid M.; Docherty, Kenneth S.; Sueper, D. T.; Kimmel, Joel; Worsnop, Douglas R.; Trimborn, Achim; Northway, Megan; Stone, Elizabeth A.; Schauer, James J.; Volkamer, Rainer M.; Fortner, Edward; de Foy, B.; Wang, Jian; Laskin, Alexander; Shutthanandan, V.; Zheng, Junsheng; Zhang, Renyi; Gaffney, Jeffrey S.; Marley, Nancy A.; Paredes-Miranda, Guadalupe L.; Arnott, W. P.; Molina, Luisa T.; Sosa, G.; Jimenez, Jose L.

2009-09-11T23:59:59.000Z

325

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 heterogeneity. In particular, biogeochemical fluxes of volatiles such as methane remain largely unconstrained

Girguis, Peter R.

326

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  

SciTech Connect (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 Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and complementary instrumentation. Mass concentrations, diurnal cycles, and size distributions of inorganic and organic species are similar to results from the CENICA supersite in April 2003 with organic aerosol (OA) comprising about half of the fine PM mass. Positive Matrix Factorization (PMF) analysis of the high resolution OA spectra identified three major components: chemically-reduced urban primary emissions (hydrocarbon-like OA, HOA), oxygenated OA (OOA, mostly secondary OA or SOA), and biomass burning OA (BBOA) that correlates with levoglucosan and acetonitrile. BBOA includes several very large plumes from regional fires and likely also some refuse burning. A fourth OA component is a small local nitrogen-containing reduced OA component (LOA) which accounts for 9% of the OA mass but one third of the organic nitrogen, likely as amines. OOA accounts for almost half of the OA on average, consistent with previous observations. OA apportionment results from PMF-AMS are compared to the PM{sub 2.5} chemical mass balance of organic molecular markers (CMB-OMM, from GC/MS analysis of filters). Results from both methods are overall consistent. Both assign the major components of OA to primary urban, biomass burning/woodsmoke, and secondary sources at similar magnitudes. The 2006 Mexico City emissions inventory underestimates the urban primary PM{sub 2.5} emissions by a factor of {approx}4, and it is {approx}16 times lower than afternoon concentrations when secondary species are included. Additionally, the forest fire contribution is at least an order-of-magnitude larger than in the inventory.

Aiken, A.C.; Wang, J.; Salcedo, D.; Cubison, M. J.; Huffman, J. A.; DeCarlo, P. F.; Ulbrich, I. M.; Docherty, K. S.; Sueper, D.; Kimmel, J. R.; Worsnop, D. R.; Trimborn, A.; Northway, M.; Stone, E. A.; Schauer, J. J.; Volkamer, R. M.; Fortner, E.; de Foy, B.; Laskin, A.; Shutthanandan, V.; Zheng, J.; Zhang, R.; Gaffney, J.; Marley, N. A.; Paredes-Miranda, G.; Arnott, W. P.; Molina, L. T.; Sosa, G.; Jimenez, J. L.

2009-09-01T23:59:59.000Z

327

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

SciTech Connect (OSTI)

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

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

2011-01-01T23:59:59.000Z

328

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

SciTech Connect (OSTI)

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

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

2014-04-30T23:59:59.000Z

329

Quadrupole mass spectrometry and time-of-flight analysis of ions resulting from 532 nm pulsed laser ablation of Ni, Al, and ZnO targets  

SciTech Connect (OSTI)

This work describes the design and validation of an instrument to measure the kinetic energies of ions ejected by the pulsed laser ablation (PLA) of a solid target. Mass spectra show that the PLA of Ni, Al, and ZnO targets, in vacuum, using the second harmonic of a Nd:YAG laser (532 nm, pulse duration {approx}10 ns) generates abundant X{sup n+} ions (n{<=}3 for Ni, {<=}2 for Al, {<=}3 and {<=}2 for Zn and O respectively from ZnO). Ions are selected by their mass/charge (m/z) ratio prior to the determination of their times of flight. PLA of Ni has been studied in most detail. The mean velocities of ablated Ni{sup n+} ions are shown to follow the trend v(Ni{sup 3+})>v(Ni{sup 2+})>v(Ni{sup +}). Data from Ni{sup 2+} and Ni{sup 3+} are fitted to shifted Maxwellian functions and agree well with a model which assumes both thermal and Coulombic contributions to ion velocities. The dependence of ion velocities on laser pulse energy (and fluence) is investigated, and the high energy data are shown to be consistent with an effective accelerating voltage of {approx}90 V within the plume. The distribution of velocities associated with Ni{sup 3+} indicates a population at cooler temperature than Ni{sup 2+}.

Sage, Rebecca S.; Cappel, Ute B.; Ashfold, Michael N. R.; Walker, Nicholas R. [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom)

2008-05-01T23:59:59.000Z

330

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

E-Print Network [OSTI]

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

American Society for Testing and Materials. Philadelphia

2000-01-01T23:59:59.000Z

331

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

SciTech Connect (OSTI)

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

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

2010-01-01T23:59:59.000Z

332

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

SciTech Connect (OSTI)

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

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

2011-02-01T23:59:59.000Z

333

Applications of High-Resolution Electrospray Ionization Mass...  

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

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

334

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

335

Interface and process for enhanced transmission of non-circular ion beams between stages at unequal pressure  

DOE Patents [OSTI]

The invention discloses a new interface with non-circular conductance limit aperture(s) useful for effective transmission of non-circular ion beams between stages with different gas pressure. In particular, the invention provides an improved coupling of field asymmetric waveform ion mobility spectrometry (FAIMS) analyzers of planar or side-to-side geometry to downstream stages such as mass spectrometry or ion mobility spectrometry. In this case, the non-circular aperture is rectangular; other geometries may be optimum in other applications. In the preferred embodiment, the non-circular aperture interface is followed by an electrodynamic ion funnel that may focus wide ion beams of any shape into tight circular beams with virtually no losses. The jet disrupter element of the funnel may also have a non-circular geometry, matching the shape of arriving ion beam. The improved sensitivity of planar FAIMS/MS has been demonstrated in experiments using a non-contiguous elongated aperture but other embodiments (e.g., with a contiguous slit aperture) may be preferable, especially in conjunction with an ion funnel operated at high pressures.

Tang, Keqi (Richland, WA); Shvartsburg, Alexandre A. (Richland, WA); Smith, Richard D. (Richland, WA)

2008-03-04T23:59:59.000Z

336

The use the a high intensity neutrino beam from the ESS proton linac for measurement of neutrino CP violation and mass hierarchy  

E-Print Network [OSTI]

It is proposed to complement the ESS proton linac with equipment that would enable the production, concurrently with the production of the planned ESS beam used for neutron production, of a 5 MW beam of 10$^{23}$ 2.5 GeV protons per year in microsecond short pulses to produce a neutrino Super Beam, and to install a megaton underground water Cherenkov detector in a mine to detect $\

Baussan, E; Ekelof, T; Martinez, E Fernandez; Ohman, H; Vassilopoulos, N

2012-01-01T23:59:59.000Z

337

The use of a high intensity neutrino beam from the ESS proton linac for measurement of neutrino CP violation and mass hierarchy  

E-Print Network [OSTI]

It is proposed to complement the ESS proton linac with equipment that would enable the production, concurrently with the production of the planned ESS beam used for neutron production, of a 5 MW beam of 10$^{23}$ 2.5 GeV protons per year in microsecond short pulses to produce a neutrino Super Beam, and to install a megaton underground water Cherenkov detector in a mine to detect $\

E. Baussan; M. Dracos; T. Ekelof; E. Fernandez Martinez; H. Ohman; N. Vassilopoulos

2013-02-09T23:59:59.000Z

338

ablation-absorption ratio spectrometry: Topics by E-print Network  

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

isotopes 2 A gas chromatographypyrolysisisotope ratio mass spectrometry system for high-precision dD measurements Environmental Sciences and Ecology Websites Summary: of...

339

Mass spectrometry with a very small cyclotron  

SciTech Connect (OSTI)

It is proposed that direct detection of natural radioisotopes can be accomplished by using a very low energy (20 to 100 keV) cyclotron accelerating negative ions.

Muller, R.A.; Tans, P.P.; Mast, T.S.; Welch, J.J.

1981-05-01T23:59:59.000Z

340

Mapping Molecular Space with Mass Spectrometry /  

E-Print Network [OSTI]

L & Owende P (2010) Biofuels from microalgae—A review of2009) Microalgae as a raw material for biofuels production.microalgae. Current research aims to produce traditional biofuels

Nguyen, Don Duy

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam mass spectrometry" 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

Signatures for Mass Spectrometry Data Quality  

SciTech Connect (OSTI)

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

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

2014-03-10T23:59:59.000Z

342

Mapping Molecular Space with Mass Spectrometry /  

E-Print Network [OSTI]

microalgae. Current research aims to produce traditional biofuels from algae, but their potential to generate sustainable energy

Nguyen, Don Duy

2013-01-01T23:59:59.000Z

343

PHOTOIONIZED TOF MASS SPECTROMETRY OF ATOMIC CLUSTERS  

E-Print Network [OSTI]

for sev eral cluster sou rce nozzle condition s. Heliu m gas pressu re at the tim e of v aporization of solid m aterial played the key role in cluster size range obtain ed. Th e effect of pressu re was thorou

Maruyama, Shigeo

344

Mapping Molecular Space with Mass Spectrometry /  

E-Print Network [OSTI]

L & Oliveira AC (2009) Microalgae as a raw material forP (2010) Biofuels from microalgae—A review of technologiesThe tide turns towards microalgae. Current research aims to

Nguyen, Don Duy

2013-01-01T23:59:59.000Z

345

Improving liquid chromatography-mass spectrometry sensitivity...  

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

sensitivity using a subambient pressure ionization with nanoelectrospray (SPIN Abstract: In this work the Subambient Pressure Ionization with Nanoelectrospray (SPIN) ion...

346

Ultrasensitive Nanoelectrospray Ionization-Mass Spectrometry using  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIAUltrafast Transformations

347

Next-Generation Mass Spectrometry | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the Contributions andDataNationalNewport News Business55NewsNext Jefferson

348

CAMS Center for Accelerator Mass Spectrometry  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation InInformation InExplosion Monitoring:Home| Visitors| Education|About NationalEnergyWhy the

349

Application of Electron Transfer Dissociation Mass Spectrometry...  

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

glycation of peptides and proteins by D-glucose has important implications in diabetes mellitus research, particularly in the context of development of diabetic...

350

Beyond single particle mass spectrometry: multidimensional characterisation  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6 M. Babzien, I.Program Information AboutBetterBetter Nationalof

351

Electrospray Mass Spectrometry | The Ames Laboratory  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing Zirconia Nanoparticles as SelectiveElectronic Structurefunctional

352

Signatures for Mass Spectrometry Data Quality. | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBi (2)Sharing Smart GridShift EndSidney D.Christopher

353

Colliding neutrino beams  

E-Print Network [OSTI]

From several neutrino oscillation experiments, we understand now that neutrinos have mass. However, we really don't know what mechanism is responsible for producing this neutrino mass. Current or planned neutrino experiments utilize neutrino beams and long-baseline detectors to explore flavor mixing but do not address the question of the origin of neutrino mass. In order to answer that question, neutrino interactions need to be explored at much higher energies. This paper outlines a program to explore neutrinos and their interactions with various particles through a series of experiments involving colliding neutrino beams.

Reinhard Schwienhorst

2007-11-08T23:59:59.000Z

354

PUBLISHED VERSION Study of runaway electrons with Hard X-ray spectrometry of tokamak plasmas  

E-Print Network [OSTI]

and DEMO, HXR spectrometry will be useful providing information on runaway electron energy, runaway beam as high as tens of MeV and the runaway current is more than 1 MA. The final runaway energy can becomePUBLISHED VERSION Study of runaway electrons with Hard X-ray spectrometry of tokamak plasmas

355

Metallic beam development for the Facility for Rare Isotope Beam  

SciTech Connect (OSTI)

The Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU) will accelerate a primary ion beam to energies beyond 200 MeV/u using a superconducting RF linac and will reach a maximum beam power of 400 kW on the fragmentation target. The beam intensity needed from the ECR ion source is expected to be between 0.4 and 0.5 emA for most medium mass to heavy mass elements. Adding to the challenge of reaching the required intensity, an expanded list of primary beams of interest has been established based on the production rate and the number of isotope beams that could be produced with FRIB. We report here on the development done for some of the beam in the list including mercury (natural), molybdenum ({sup 98}Mo), and selenium ({sup 82}Ser)

Machicoane, Guillaume, E-mail: machicoa@nscl.msu.edu; Cole, Dallas; Leitner, Daniela; Neben, Derek; Tobos, Larry [Facility for Rare Isotope Beam, Michigan State University, East Lansing, Michigan 48824 (United States)] [Facility for Rare Isotope Beam, Michigan State University, East Lansing, Michigan 48824 (United States)

2014-02-15T23:59:59.000Z

356

High-Speed Tandem Mass Spectrometric in Situ Imaging by Nanospray...  

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

in Situ Imaging by Nanospray Desorption Electrospray Ionization Mass Spectrometry. High-Speed Tandem Mass Spectrometric in Situ Imaging by Nanospray Desorption Electrospray...

357

Surface Science Analysis of GaAs Photocathodes Following Sustained Electron Beam Delivery  

SciTech Connect (OSTI)

Degradation of the photocathode materials employed in photoinjectors represents a challenge for sustained operation of nuclear physics accelerators and high power Free Electron Lasers (FEL). Several photocathode degradation processes are suspected, including defect formation by ion back bombardment, photochemistry of surface adsorbed species and irradiation-induced surface defect formation. To better understand the mechanisms of photocathode degradation, we have conducted surface and bulk analysis studies of two GaAs photocathodes removed from the FEL photoinjector after delivering electron beam for a few years. The analysis techniques include Helium Ion Microscopy (HIM), Rutherford Backscattering Spectrometry (RBS), Atomic Force Microscopy (AFM) and Secondary Ion Mass Spectrometry (SIMS). In addition, strained super-lattice GaAs photocathode samples, removed from the CEBAF photoinjector were analyzed using Transmission Electron Microscopy (TEM) and SIMS. This analysis of photocathode degradation during nominal photoinjector operating conditions represents first steps towards developing robust new photocathode designs necessary for generating sub-micron emittance electron beams required for both fourth generation light sources and intense polarized CW electron beams for nuclear and high energy physics facilities.

Shutthanandan, V.; Zhu, Zihua; Stutzman, Marcy L.; Hannon, Fay; Hernandez-Garcia, Carlos; Nandasiri, Manjula I.; Kuchibhatla, Satyanarayana V N T; Thevuthasan, Suntharampillai; Hess, Wayne P.

2012-06-12T23:59:59.000Z

358

Investigation of high temperature gaseous species by Knudsen cell mass spectrometry above the condensed systems Cu-Y-Ru-C, Ag-Y-Ru-C, and Au-Y- Ru-C  

E-Print Network [OSTI]

of the total ion intensities listed in Tables 2 through 5, + + except those for RuC and YC2, were calculated by dividing the individual isotopic species by the isotopic abundance of that species according to Equation 1, where I is the total intensity of all... not be used because their mass to charge ratios overlap. For these iona, an + algebraic equation was used which compared the ratios of YC (Mass 113), YC2 (Mass 114), RuC (Mass 113), and RuC (Mass 114). The + + + calculated isotopic abundances...

Wilhite, Dale Wayne

1988-01-01T23:59:59.000Z

359

Low energy beta-beams  

E-Print Network [OSTI]

The main goal of a beta-beam facility is to determine the possible existence of CP violation in the lepton sector, the value of the third neutrino mixing angle and the mass hierarchy. Here we argue that a much broader physics case can be covered since the beta-beam concept can also be used to establish a low energy beta-beam facility. We discuss that the availability of neutrino beams in the 100 MeV energy range offers a unique opportunity to perform neutrino scattering experiments of interest for nuclear physics, for the study of fundamental interactions and of core-collapse supernova physics.

Cristina Volpe

2009-11-13T23:59:59.000Z

360

JOURNAL DE PHYSIQUE Colloque C 2, supplkment au no 3-4, Tome 28, mars-avril1967, page C 2 -87 RAPID SCANNING FOURIER TRANSFORM SPECTROMETRY  

E-Print Network [OSTI]

scanning serves to mitigate the problems of scintillation and dynamic range for Fourier spectrometry. Scintillation noise due to atmospheric turbulence can easily relegate astronomical spectrometry to the last RAPID SCANNING FOURIER TRANSFORM SPECTROMETRY Block Associates, Inc., Cambridge, Mass., U. S. A. Rksumk

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "beam mass spectrometry" 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

Microchip and wedge ion funnels and planar ion beam analyzers using same  

DOE Patents [OSTI]

Electrodynamic ion funnels confine, guide, or focus ions in gases using the Dehmelt potential of oscillatory electric field. New funnel designs operating at or close to atmospheric gas pressure are described. Effective ion focusing at such pressures is enabled by fields of extreme amplitude and frequency, allowed in microscopic gaps that have much higher electrical breakdown thresholds in any gas than the macroscopic gaps of present funnels. The new microscopic-gap funnels are useful for interfacing atmospheric-pressure ionization sources to mass spectrometry (MS) and ion mobility separation (IMS) stages including differential IMS or FAIMS, as well as IMS and MS stages in various configurations. In particular, "wedge" funnels comprising two planar surfaces positioned at an angle and wedge funnel traps derived therefrom can compress ion beams in one dimension, producing narrow belt-shaped beams and laterally elongated cuboid packets. This beam profile reduces the ion density and thus space-charge effects, mitigating the adverse impact thereof on the resolving power, measurement accuracy, and dynamic range of MS and IMS analyzers, while a greater overlap with coplanar light or particle beams can benefit spectroscopic methods.

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

2012-10-30T23:59:59.000Z

362

Beam History  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6 M. Babzien, I. Ben-Zvi, P. StudyBeam History PrintBeam History

363

Spectral networks algorithms for de novo interpretation of tandem mass spectra  

E-Print Network [OSTI]

high-energy collision-induced dissociation spectra of singly protonated peptides by ’SeqMS’, a software aid for de novo sequencing by tandem mass spectrometry.

Bandeira, Nuno Filipe Cabrita

2007-01-01T23:59:59.000Z

364

andliquid chromatography-tandem mass: Topics by E-print Network  

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

using isotope dilution high performance liquid chromatography-tandem mass spectrometry. Open Access Theses and Dissertations Summary: ??A method has been developed for...

365

aerosol time-of-flight mass: Topics by E-print Network  

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

Theses and Dissertations Summary: ??The construction of a liquid nitrogen-cooled ion mobility spectrometer coupled with time-of-flight mass spectrometry was implemented to...

366

Beams 92: Proceedings. Volume 2, Ion beams, electron beams, diagnostics  

SciTech Connect (OSTI)

This report contains papers on the following topics. Ion beam papers; electron beam papers; and these papers have been indexed separately elsewhere.

Mosher, D.; Cooperstein, G. [eds.] [Naval Research Lab., Washington, DC (United States)] [eds.; Naval Research Lab., Washington, DC (United States)

1993-12-31T23:59:59.000Z

367

Surface science analysis of GaAs photocathodes following sustained electron beam delivery  

SciTech Connect (OSTI)

Degradation of the photocathode materials employed in photoinjectors represents a challenge for sustained operation of nuclear physics accelerators and high power Free Electron Lasers (FEL). Photocathode quantum efficiency (QE) degradation is due to residual gasses in the electron source vacuum system being ionized and accelerated back to the photocathode. These investigations are a first attempt to characterize the nature of the photocathode degradation, and employ multiple surface and bulk analysis techniques to investigate damage mechanisms including sputtering of the Cs-oxidant surface monolayer, other surface chemistry effects, and ion implantation. Surface and bulk analysis studies were conducted on two GaAs photocathodes, which were removed from the JLab FEL DC photoemission gun after delivering electron beam, and two control samples. The analysis techniques include Helium Ion Microscopy (HIM), Rutherford Backscattering Spectrometry (RBS), Atomic Force Microscopy (AFM) and Secondary Ion Mass Spectrometry (SIMS). In addition, two high-polarization strained superlattice GaAs photocathode samples, one removed from the Continuous Electron Beam Accelerator Facility (CEBAF) photoinjector and one unused, were also analyzed using Transmission Electron Microscopy (TEM) and SIMS. It was found that heat cleaning the FEL GaAs wafer introduces surface roughness, which seems to be reduced by prolonged use. The bulk GaAs samples retained a fairly well organized crystalline structure after delivering beam but shows evidence of Cs depletion on the surface. Within the precision of the SIMS and RBS measurements the data showed no indication of hydrogen implantation or lattice damage from ion back bombardment in the bulk GaAs wafers. In contrast, SIMS and TEM measurements of the strained superlattice photocathode show clear crystal damage in the wafer from ion back bombardment.

Carlos Hernandez-Garcia, Fay Hannon, Marcy Stutzman, V. Shutthanandan, Z. Zhu, M. Nandasri, S. V. Kuchibhatla, S. Thevuthasan, W. P. Hess

2012-06-01T23:59:59.000Z

368

Temperature dependence of ion-beam mixing in crystalline and amorphous germanium isotope multilayer structures  

SciTech Connect (OSTI)

Self-atom mixing induced by 310 keV gallium (Ga) ion implantation in crystalline and preamorphized germanium (Ge) at temperatures between 164 K and 623 K and a dose of 1?×?10{sup 15}?cm{sup ?2} is investigated using isotopic multilayer structures of alternating {sup 70}Ge and {sup nat}Ge layers grown by molecular beam epitaxy. The distribution of the implanted Ga atoms and the ion-beam induced depth-dependent self-atom mixing was determined by means of secondary ion mass spectrometry. Three different temperature regimes of self-atom mixing, i.e., low-, intermediate-, and high-temperature regimes are observed. At temperatures up to 423 K, the mixing is independent of the initial structure, whereas at 523?K, the intermixing of the preamorphized Ge structure is about twice as high as that of crystalline Ge. At 623?K, the intermixing of the initially amorphous Ge structure is strongly reduced and approaches the mixing of the crystalline material. The temperature dependence of ion-beam mixing is described by competitive amorphization and recrystallization processes.

Radek, M.; Bracht, H., E-mail: bracht@uni-muenster.de [Institute of Materials Physics, Westfälische Wilhelms-Universität Münster, 48149 Münster (Germany); Posselt, M.; Liedke, B.; Schmidt, B. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, D-01328 Dresden (Germany); Bougeard, D. [Institut für Experimentelle und Angewandte Physik, 93040 Regensburg (Germany)

2014-01-14T23:59:59.000Z

369

Mexico City Aerosol Analysis during MILAGRO using High Resolution Aerosol Mass Spectrometry at the Urban Supersite (T0). Part 2: Analysis of the Biomass Burning Contribution and the Modern Carbon Fraction  

SciTech Connect (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 Matrix Factorization (PMF) of high resolution AMS spectra identified a biomass burning OA (BBOA) component, which includes several large plumes that appear to be from forest fires within the region. Here, we show that the AMS BBOA concentration at T0 correlates with fire counts in the vicinity of Mexico City and that most of the BBOA variability is captured when the FLEXPART model is used for the dispersion of fire emissions as estimated from satellite fire counts. The resulting FLEXPART fire impact index correlates well with the observed BBOA, CH3CN, levoglucosan, and potassium, indicating that wildfires in the region surrounding Mexico City are the dominant source of BBOA at T0 during MILAGRO. The impact of distant BB sources such as the Yucatan is very small during this period. All fire tracers are correlated, with BBOA and levoglucosan showing little background, acetonitrile having a well-known tropospheric background of ~100-150 ppt, and PM2.5 potassium having a background of ~160 ng m-3 (two-thirds of its average concentration), which does not appear to be related to BB sources.

Aiken, Allison; de Foy, B.; Wiedinmyer, Christine; DeCarlo, Peter; Ulbrich, Ingrid M.; Wehrli, M. N.; Szidat, S.; Prevot, A. S. H.; Noda, J.; Wacker, L.; Volkamer, Rainer M.; Fortner, Edward; Wang, J. X.; Laskin, Alexander; Shutthanandan, V.; Zheng, J.; Zhang, Renyi; Paredes-Miranda, Guadalupe L.; Arnott, W. P.; Molina, Luis; Sosa, G.; Querol, X.; Jimenez, J. L.

2010-06-16T23:59:59.000Z

370

Non-covalent Interactions: Effects on Gas-phase Ion Structure and Reactivity  

E-Print Network [OSTI]

binding energies, such as high pressure mass spectrometry orhigh-pressure drift cell experiments, 37 energy resolved surface induced dissociation, 38, 39 or guided ion beam mass spectrometry,

Prell, James Stephen

2011-01-01T23:59:59.000Z

371

International Journal of Mass Spectrometry 260 (2007) 222–236 Extended data analysis strategies for high resolution imaging MS: New methods to deal with extremely large image hyperspectral datasets  

E-Print Network [OSTI]

The large size of the hyperspectral datasets that are produced with modern mass spectrometric imaging techniques makes it difficult to analyze the results. Unsupervised statistical techniques are needed to extract relevant information from these datasets and reduce the data into a surveyable overview. Multivariate statistics are commonly used for this purpose. Computational power and computer memory limit the resolution at which the datasets can be analyzed with these techniques. We introduce the use of a data format capable of efficiently storing sparse datasets for multivariate analysis. This format is more memory-efficient and therefore it increases the possible resolution together with a decrease of computation time. Three multivariate techniques are compared for both sparse-type data and non-sparse data acquired in two different imaging ToF-SIMS experiments and one LDI-ToF imaging experiment. There is no significant qualitative difference in the use of different data formats for the same multivariate algorithms. All evaluated multivariate techniques could be applied on both SIMS and the LDI imaging datasets. Principal component analysis is shown to be the fastest choice; however a small increase of computation time using a VARIMAX optimization increases the decomposition quality significantly. PARAFAC analysis is shown to be very effective in separating different chemical components but the calculations take a significant amount of time, limiting its use as a routine technique. An effective visualization of the results of the multivariate analysis is as important for the analyst as the computational issues. For this reason, a new technique for visualization is presented, combining both spectral loadings and spatial

Leendert A. Klerk A; Er Broersen B; Ian W. Fletcher C

2006-01-01T23:59:59.000Z

372

Accelerator beam profile analyzer  

DOE Patents [OSTI]

A beam profile analyzer employing sector or quadrant plates each servo controlled to outline the edge of a beam.

Godel, Julius B. (Bayport, NY); Guillaume, Marcel (Grivegnee, BE); Lambrecht, Richard M. (East Quogue, NY); Withnell, Ronald (East Setauket, NY)

1976-01-01T23:59:59.000Z

373

Vacuum-Ultraviolet Photoionization and Mass Spectrometric Characterization of Lignin Monomers Coniferyl and Sinapyl Alcohols  

SciTech Connect (OSTI)

The fragmentation mechanisms of monolignols under various energetic processes are studied with jet-cooled thermal desorption molecular beam (TDMB) mass spectrometry (MS), 25 keV Bi3+ secondary ion MS (SIMS), synchrotron vacuum-ultraviolet secondary neutral MS (VUV-SNMS) and theoretical methods. Experimental and calculated appearance energies of fragments observed in TDMB MS indicate that the coniferyl alcohol photoionization mass spectra contain the molecular parent and several dissociative photoionization products. Similar results obtained for sinapyl alcohol are also discussed briefly. Ionization energies of 7.60 eV ? 0.05 eV for coniferyl alcohol and<7.4 eV for both sinapyl and dihydrosinapyl alcohols are determined. The positive ion SIMS spectrum of coniferyl alcohol shares few characteristic peaks (m/z = 137 and 151) with the TDMB mass spectra, shows extensive fragmentation, and does not exhibit clear molecular parent signals. VUV-SNMS spectra, on the other hand, are dominated by the parent ion and main fragments also present in the TDMB spectra. Molecular fragmentation in VUV-SNMS spectra can be reduced by increasing the extraction delay time. Some features resembling the SIMS spectra are also observed in the desorbed neutral products. The monolignol VUV-SNMS peaks shared with the TDMB mass spectra suggest that dissociative photoionization of ion-sputtered neutral molecules predominate in the VUV-SNMS mass spectra, despite the extra internal energy imparted in the initial ion impact. The potential applications of these results to imaging mass spectrometry of bio-molecules are discussed.

Takahashi, Lynelle K.; Zhou, Jia; Kostko, Oleg; Golan, Amir; Leone, Stephen R.; Ahmed, Musahid

2011-02-09T23:59:59.000Z

374

Anal. Chem. 1981, 53, 1241-1244 1241 Comparison of Mass Spectra Obtained with Low-Energy Ion  

E-Print Network [OSTI]

and High-Energy Californium-252 Fission Fragment Bombardment Werner Ens and K. G. Standing Physics mass spectrometry (1,2)and low-energy ion bombardment mass spectrometry (3-5). In these techniquesAnal. Chem. 1981, 53, 1241-1244 1241 Comparison of Mass Spectra Obtained with Low-Energy Ion

Chait, Brian T.

375

Beam History  

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

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376

Beam History  

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

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377

Beam Transport  

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

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378

Beam Status  

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

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379

Beam geometry selection using sequential beam addition  

SciTech Connect (OSTI)

Purpose: The selection of optimal beam geometry has been of interest since the inception of conformal radiotherapy. The authors report on sequential beam addition, a simple beam geometry selection method, for intensity modulated radiation therapy. Methods: The sequential beam addition algorithm (SBA) requires definition of an objective function (score) and a set of candidate beam geometries (pool). In the first iteration, the optimal score is determined for each beam in the pool and the beam with the best score selected. In the next iteration, the optimal score is calculated for each beam remaining in the pool combined with the beam selected in the first iteration, and the best scoring beam is selected. The process is repeated until the desired number of beams is reached. The authors selected three treatment sites, breast, lung, and brain, and determined beam arrangements for up to 11 beams from a pool comprised of 25 equiangular transverse beams. For the brain, arrangements were additionally selected from a pool of 22 noncoplanar beams. Scores were determined for geometries comprised equiangular transverse beams (EQA), as well as two tangential beams for the breast case. Results: In all cases, SBA resulted in scores superior to EQA. The breast case had the strongest dependence on beam geometry, for which only the 7-beam EQA geometry had a score better than the two tangential beams, whereas all SBA geometries with more than two beams were superior. In the lung case, EQA and SBA scores monotonically improved with increasing number of beams; however, SBA required fewer beams to achieve scores equivalent to EQA. For the brain case, SBA with a coplanar pool was equivalent to EQA, while the noncoplanar pool resulted in slightly better scores; however, the dose-volume histograms demonstrated that the differences were not clinically significant. Conclusions: For situations in which beam geometry has a significant effect on the objective function, SBA can identify arrangements equivalent to equiangular geometries but using fewer beams. Furthermore, SBA provides the value of the objective function as the number of beams is increased, allowing the planner to select the minimal beam number that achieves the clinical goals. The method is simple to implement and could readily be incorporated into an existing optimization system.

Popple, Richard A., E-mail: rpopple@uabmc.edu; Brezovich, Ivan A.; Fiveash, John B. [Department of Radiation Oncology, The University of Alabama at Birmingham, 1720 2nd Avenue South, Birmingham, Alabama 35294 (United States)] [Department of Radiation Oncology, The University of Alabama at Birmingham, 1720 2nd Avenue South, Birmingham, Alabama 35294 (United States)

2014-05-15T23:59:59.000Z

380

Beam-Bem interactions  

SciTech Connect (OSTI)

In high energy storage-ring colliders, the nonlinear effect arising from beam-beam interactions is a major source that leads to the emittance growth, the reduction of beam life time, and limits the collider luminosity. In this paper, two models of beam-beam interactions are introduced, which are weak-strong and strong-strong beam-beam interactions. In addition, space-charge model is introduced.

Kim, Hyung Jin; /Fermilab

2011-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam mass spectrometry" 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

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

E-Print Network [OSTI]

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

Lucas, Jessica Elaine

2004-09-30T23:59:59.000Z

382

High performance double pulse doped pseudomorphic AlGaAs/InGaAs transistors grown by molecular-beam epitaxy  

SciTech Connect (OSTI)

Double pulse doped AlGaAs/InGaAs pseudomorphic high electron mobility transistors have been grown by molecular-beam epitaxy on GaAs substrates. Hall mobilities in excess of 7100 cm{sup 2}/V s at 300 K and 25000 cm{sup 2}/V s at 77 K are obtained with a sheet density of 3 x 10{sup 12} cm{sup {minus}2}. Photoluminescence measurements indicate that two electronic subbands are occupied, and the subband energies are determined. The doping pulses are resolved in secondary ion mass spectrometry measurements. Using a double recess process, transistors have been fabricated that have produced state of the art microwave performance. At 10 GHz a 1.2 mm device has simultaneously achieved a power added efficiency of 70%, output power of 0.97 W, and gain of 10 dB. 17 refs., 5 figs., 1 tab.

Hoke, W.E.; Lyman, P.S.; Labossier, W.H.; Brierley, S.K.; Hendriks, H.T.; Shanfield, S.R.; Aucoin, L.M.; Kazior, T.E. [Raytheon Research Division, Lexington, MA (United States)] [Raytheon Research Division, Lexington, MA (United States)

1992-05-01T23:59:59.000Z

383

Algorithms for tandem mass spectrometry-based proteomics  

E-Print Network [OSTI]

An introduction to the conjugate gradient method without theusing a nonlinear Conjugate Gradient method [196]. LogisticA nonlinear Conjugate Gradient method [196] was used to

Frank, Ari Michael

2008-01-01T23:59:59.000Z

384

Mass Spectrometry and Density Functional Theory Characterizations of DNA Modifications  

E-Print Network [OSTI]

alkaline phosphatase (CIP). We chose Incorporation of DNADigestion NP1, exoPII, CIP, exoPI + Internal Standard Enzymethe addition of exoPI and CIP. Similar to NPI, exoPI creates

Williams, Renee Therese

2012-01-01T23:59:59.000Z

385

Plasma desorption mass spectrometry of organics at low temperatures  

E-Print Network [OSTI]

The desorption/ionization of volatile hydrocarbons by Plasma Desorption (PD) produces a series of molecular ions. Among these are deprotonated molecular ions, which are not usually observed in PD. The H-loss phenomenon was examined as a function...

Shirey, Eldon Lynn

1993-01-01T23:59:59.000Z

386

Extending the Capabilities of Single Particle Mass Spectrometry...  

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

nm creating a distinct sharp feature on the small particle side 11 of the vacuum aerodynamic size distribution. Thus, the two quantities needed to determine 12 particle...

387

Quantitative analysis of amino acid mixtures by mass spectrometry  

E-Print Network [OSTI]

C~hto Gibert& and J. Oro, 'l, 604 (1969). 16. S. D. Cliristian, 0. Chem. Educ. , 42, 604 (1965) 17. L. G. Sillcri, Acta Chem. Scancl. , I8, 1085 (1964) 18. R. D. Gr i@shy, C. O. Ilaiisen, D. G. I"lai, ne. in9, G. Eox, and R. II. Cole, Ar al...

Bird, James Spencer

1971-01-01T23:59:59.000Z

388

Algorithms for tandem mass spectrometry-based proteomics  

E-Print Network [OSTI]

By restricting this advanced search to the set of unidenti?require time-consuming advanced search techniques. Insteadimplementation of the advanced database searches such as the

Frank, Ari Michael

2008-01-01T23:59:59.000Z

389

Deuterium exchange mass spectrometry studies of the phospholipase A? superfamily  

E-Print Network [OSTI]

of inhibitor bound GIVA PLA 2 using molecular modeling andDXMS Studies of Group IA PLA 2 Utilizing Novel Methods forIA phospholipase A 2 (GIA PLA 2 ) was carried out in the

Burke, John Edmund

2008-01-01T23:59:59.000Z

390

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

391

Mass spectrometry-based discovery of circadian peptides  

E-Print Network [OSTI]

with space and time. Two solid-phase extraction collection strategies are presented that relate time in the brain. little SAAS neuropeptides solid-phase extraction peptidomics suprachiasmatic nucleus neuropeptide- based transmitters and modulators within dynamic neural net- works. Neuropeptides include a broad

Gillette, Martha U.

392

Isoelectric Trapping and Mass Spectrometry: Tools for Proteomics  

E-Print Network [OSTI]

extremely complex mixtures leading to the coupling of different chromatographic and/or electrophoretic techniques.14 MULTI-DIMENSIONAL PROTEIN IDENTIFICATION TEHCHNOLOGY One of the most utilized techniques for bottom-up proteomic studies... researchers prefer an experimental platform that utilizes 1D or 2D-GE followed by excision of each protein band (or entire gel lanes) and tryptic digestion.25 The resulting peptides are then subjected to MS analysis or are separated using LC (GeLC) prior...

Cologna, Stephanie Marie

2012-02-14T23:59:59.000Z

393

Applications of Ionic Clusters in High Resolution Mass Spectrometry  

E-Print Network [OSTI]

with the solvation energies of the reactant E solv (3+)and product E solv (2+) clusters (eq 2 and 3) obtained from6 (H 2 O) n 3+(g) #G = –E solv (3+) Ru(NH 3 ) 6 (H 2 O) n 2

Leib, Ryan David

2010-01-01T23:59:59.000Z

394

Targeted Tandem Mass Spectrometry for High-Throughput Comparative  

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

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395

New Mass Spectrometry Techniques for Studying Physical Chemistry of  

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

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396

Secondary Ion Mass Spectrometry Imaging of Dictyostelium discoideum  

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397

Absorption Mode FT-ICR Mass Spectrometry Imaging. | EMSL  

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398

21 Tesla mass spectrometry magnet arrives at EMSL | EMSL  

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399

Picoelectrospray Ionization Mass Spectrometry Using Narrow-bore Chemically  

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

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400

High-Resolution Desorption Electrospray Ionization Mass Spectrometry...  

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

between different mechanisms of chemical aging. Citation: Laskin J, A Laskin, PJ Roach, GW Slysz, GA Anderson, S Nizkorodov, DL Bones, and L Nguyen.2010."High-Resolution...

Note: This page contains sample records for the topic "beam mass spectrometry" 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

Investigation of Metalloproteins Utilizing High Resolution Mass Spectrometry  

E-Print Network [OSTI]

.............................................................. 79 30 Fragment ion spectra of the [M+H]+ ions (a) Ac- Y(AEAAKA)2F-NH2 (-OCH3), (b) Ac-Y(AEAAKA)2F-NH2 (- 2OCH3) and (c) Ac-Y(AEAAKA)2F-NH2 (-3CH3)................. 82 31 Arrival time distribution (ATD) of the [M+H]+ ions of (a) Ac- Y...(AEAAKA)2F-NH2 (3OCH3) (FWHM:14), (b) Ac- Y(AEAAKA)2F-NH2 (2OCH3) (FWHM:25), (c) Ac- Y(AEAAKA)2F-NH2 (OCH3) (FWHM:21) and (d) Ac- Y(AEAAKA)2F-NH2 (FWHM:31)......................................... 85 32 Arrival time distribution (ATD) of the [M...

Wu, Zhaoxiang

2011-08-08T23:59:59.000Z

402

Monitoring Trace Radionuclides by ICP Mass Spectrometry with Femtosecond  

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

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403

Multiplexed Ion Mobility Spectrometry - Orthogonal Time-Of-Flight Mass  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment SurfacesResource ProgramModificationEnzyme-Functionalized Gold Nanorod Labels and

404

The future of liquid chromatography-mass spectrometry in metabolic  

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

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405

High-Resolution Desorption Electrospray Ionization Mass Spectrometry for  

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

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406

High-Resolution Electrospray Ionization Mass Spectrometry Analysis of  

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

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407

Extending the Capabilities of Single Particle Mass Spectrometry: I.  

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408

Extending the Capabilities of Single Particle Mass Spectrometry: II.  

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409

Giga-Dalton Mass Spectrometry - Energy Innovation Portal  

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410

21 Tesla mass spectrometry magnet arrives at EMSL | EMSL  

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411

Improvements in Inductively Coupled Plasma - Mass Spectrometry | The Ames  

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412

Improving liquid chromatography-mass spectrometry sensitivity using a  

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413

Automated Surface Sampling Probe for Mass Spectrometry - Energy Innovation  

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414

Liquid Chromatography Mass Spectrometry-Based Proteomics: Biological and  

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415

Liquid Chromatography-Mass Spectrometry-based Quantitative Proteomics. |  

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

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416

Mass spectrometry in biomarker applications: from untargeted discovery to  

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

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417

Mass spectrometry on bio-renewable fuels | The Ames Laboratory  

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418

Mass spectrometry-based proteomics: existing capabilities and future  

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

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419

Anasys licenses ORNL nanoscale mass spectrometry imaging technology |  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmes Laboratory Site| DepartmentInformation Systems

420

Applications of High-Resolution Electrospray Ionization Mass Spectrometry  

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

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Note: This page contains sample records for the topic "beam mass spectrometry" 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

Mass Spectrometer: Ion Mobility Spectrometry, Time of Flight | EMSL  

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

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422

Single Cell Analysis Using Microfluidics Coupled to Ultrasensitive Mass Spectrometry  

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

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423

Application of Electron Transfer Dissociation Mass Spectrometry in Analyses  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone by E-mailRadioimmunotherapy of Cancers.Appendix 2015of

424

Applications of High-Resolution Electrospray Ionization Mass Spectrometry  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone by E-mailRadioimmunotherapy ofevolved gas

425

Atmospheric Solids Analysis Probe Mass Spectrometry: A New Approach for  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone byDear Friend,Arthur J. Nozik -GrownAnAtmosphericAirborne

426

Recovering Sparse Low-rank Blocks in Tandem Mass Spectrometry  

E-Print Network [OSTI]

, Pedro Navarro2, and Richard G. Baraniuk1 1 Rice University, Houston, TX, USA; e-mail: {studer, richb}@rice.edu 2 ETH Z¨urich, Z¨urich, Switzerland; e-mail: graemepope@gmail.com, navarro

427

Anasys licenses ORNL nanoscale mass spectrometry imaging technology...  

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

in imaging resolution as small as 250 nanometers, or 1400th the thickness of a human hair. "This capability could have a tremendous impact on a broad field of applications in...

428

Hooked differential mobility spectrometry apparatus and method therefore  

DOE Patents [OSTI]

Disclosed are a device and method for improved interfacing of differential mobility spectrometry (DMS) or field asymmetric waveform ion mobility spectrometry (FAIMS) analyzers of substantially planar geometry to subsequent or preceding instrument stages. Interfacing is achieved using curved DMS elements, where a thick ion beam emitted by planar DMS analyzers or injected into them for ion filtering is compressed to the gap median by DMS ion focusing effect in a spatially inhomogeneous electric field. Resulting thinner beams are more effectively transmitted through necessarily constrained conductance limit apertures to subsequent instrument stages operated at a pressure lower than DMS, and/or more effectively injected into planar DMS analyzers. The technology is synergetic with slit apertures, slit aperture/ion funnels, and high-pressure ion funnel interfaces known in the art which allow for increasing cross-sectional area of MS inlets. The invention may be used in integrated analytical platforms, including, e.g., DMS/MS, LC/DMS/MS, and DMS/IMS/MS that could replace and/or enhance current LC/MS methods, e.g., for proteomics research.

Shvartsburg, Alexandre A [Richland, WA; Tang, Keqi [Richland, WA; Ibrahim, Yehia M [Richland, WA; Smith, Richard D [Richland, WA

2009-02-17T23:59:59.000Z

429

X-ray beam finder  

DOE Patents [OSTI]

An X-ray beam finder for locating a focal spot of an X-ray tube includes a mass of X-ray opaque material having first and second axially-aligned, parallel-opposed faces connected by a plurality of substantially identical parallel holes perpendicular to the faces and a film holder for holding X-ray sensitive film tightly against one face while the other face is placed in contact with the window of an X-ray head.

Gilbert, H.W.

1983-06-16T23:59:59.000Z

430

Electron Beams in the Low Corona A.O. Benz 1 , A. Magun 2 , W. Stehling 1 , H. Su 1;3  

E-Print Network [OSTI]

emission of electron beams at plasma densities of more than 10 11 cm \\Gamma3 . At this extremely high (0.3--1 GHz). This is the main reason why early work applying analog spectrometry with film recording

431

High speed x-ray beam chopper  

DOE Patents [OSTI]

A fast, economical, and compact x-ray beam chopper with a small mass and a small moment of inertia whose rotation can be synchronized and phase locked to an electronic signal from an x-ray source and be monitored by a light beam is disclosed. X-ray bursts shorter than 2.5 microseconds have been produced with a jitter time of less than 3 ns.

McPherson, Armon (Oswego, IL); Mills, Dennis M. (Naperville, IL)

2002-01-01T23:59:59.000Z

432

7, 64136457, 2007 Single particle mass  

E-Print Network [OSTI]

to use Mexico City as a case study of air pollution mitigation while major advances continue to improve the regional air quality.5 To help decrease particulate matter (PM) pollution in Mexico City, ACPD 7, 6413­6457, 2007 Single particle mass spectrometry of Mexico City aerosols R. C. Moffet

Paris-Sud XI, Université de

433

Cadmium measurements in coral skeleton using isotope dilutioninductively coupled plasmamass spectrometry  

E-Print Network [OSTI]

of pollution in corals growing near industri- al/urban sites where Cd concentrations can be 10 times higher­mass spectrometry Kathryn A. Matthews Department of Earth and Environmental Science, University of Pennsylvania, 240 skeleton to construct records of the frequency and intensity of oceanic upwelling. During upwelling

Mcdonough, William F.

434

Improving Alpha Spectrometry Energy Resolution by Ion Implantation with ICP-MS  

SciTech Connect (OSTI)

We report results of a novel technique using an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) as a method of source preparation for alpha spectrometry. This method produced thin, contaminant free 241Am samples which yielded extraordinary energy resolution which appear to be at the lower limit of the detection technology used in this research.

Dion, Michael P.; Liezers, Martin; Farmer, Orville T.; Miller, Brian W.; Morley, Shannon M.; Barinaga, Charles J.; Eiden, Gregory C.

2015-01-01T23:59:59.000Z

435

An overview of the facilities, activities, and developments at the University of North Texas Ion Beam Modification and Analysis Laboratory (IBMAL)  

SciTech Connect (OSTI)

The Ion Beam Modification and Analysis Laboratory (IBMAL) at the University of North Texas includes several accelerator facilities with capabilities of producing a variety of ion beams from tens of keV to several MeV in energy. The four accelerators are used for research, graduate and undergraduate education, and industrial applications. The NEC 3MV Pelletron tandem accelerator has three ion sources for negative ions: He Alphatross and two different SNICS-type sputter ion sources. Presently, the tandem accelerator has four high-energy beam transport lines and one low-energy beam transport line directly taken from the negative ion sources for different research experiments. For the low-energy beam line, the ion energy can be varied from {approx}20 to 80 keV for ion implantation/modification of materials. The four post-acceleration beam lines include a heavy-ion nuclear microprobe; multi-purpose PIXE, RBS, ERD, NRA, and broad-beam single-event upset; high-energy ion implantation line; and trace-element accelerator mass spectrometry. The NEC 3MV single-ended Pelletron accelerator has an RF ion source mainly for hydrogen, helium and heavier inert gases. We recently installed a capacitive liner to the terminal potential stabilization system for high terminal voltage stability and high-resolution microprobe analysis. The accelerator serves a beam line for standard RBS and RBS/C. Another beamline for high energy focused ion beam application using a magnetic quadrupole lens system is currently under construction. This beam line will also serve for developmental work on an electrostatic lens system. The third accelerator is a 200 kV Cockcroft-Walton accelerator with an RF ion source. The fourth accelerator is a 2.5 MV Van de Graaff accelerator, which was in operation for last several decades is currently planned to be used mainly for educational purpose. Research projects that will be briefly discussed include materials synthesis/modification for photonic, electronic, and magnetic applications, surface sputtering and micro-fabrication of materials, development of high-energy ion microprobe systems, and educational and outreach activities.

Rout, Bibhudutta; Dhoubhadel, Mangal S.; Poudel, Prakash R.; Kummari, Venkata C.; Pandey, Bimal; Deoli, Naresh T.; Lakshantha, Wickramaarachchige J.; Mulware, Stephen J.; Baxley, Jacob; Manuel, Jack E.; Pacheco, Jose L.; Szilasi, Szabolcs; Weathers, Duncan L.; Reinert, Tilo; Glass, Gary A.; Duggan, Jerry L.; McDaniel, Floyd D. [Ion Beam Modification and Analysis Laboratory, University of North Texas, Department of Physics, 1155 Union Circle 311427, Denton, Texas 76203 (United States)

2013-07-03T23:59:59.000Z

436

BEAMS3D Neutral Beam Injection Model  

SciTech Connect (OSTI)

With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.

Lazerson, Samuel

2014-04-14T23:59:59.000Z

437

Pushing the Frontier of High-Definition Ion Mobility Spectrometry...  

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

the Frontier of High-Definition Ion Mobility Spectrometry Using FAIMS. Pushing the Frontier of High-Definition Ion Mobility Spectrometry Using FAIMS. Abstract: Differential ion...

438

A TALE OF TWO BEAMS: GAUSSIAN BEAMS AND BESSEL BEAMS ROBERT L. NOWACK  

E-Print Network [OSTI]

A TALE OF TWO BEAMS: GAUSSIAN BEAMS AND BESSEL BEAMS ROBERT L. NOWACK Abstract. An overview is given of two types of focused beams, Gaussian beams and Bessel beams. First I describe some of the basic properties of Gaussian beams in homogeneous media which stay collimated over a certain distance range after

Nowack, Robert L.

439

Thomson parabola spectrometry for gold laser-generated plasmas  

SciTech Connect (OSTI)

The plasma generated from thin gold films irradiated in high vacuum at high intensity ({approx}10{sup 15} W/cm{sup 2}) laser shot is characterized in terms of ion generation through time-of-flight techniques and Thomson parabola spectrometry. Gold ions and protons, accelerated in forward direction by the electric field developed in non-equilibrium plasma, have been investigated. Measurements, performed at PALS laboratory, give information about the gold charge states distributions, the ion energy distributions and the proton acceleration driven as a function of film thickness, laser parameters, and angular emission. The ion diagnostics of produced plasma in forward direction permits to understand some mechanisms developed during its expansion kinetics. The role of the focal position of a laser beam with respect to the target surface, plasma properties, and the possibility to accelerate protons up to energies above 3 MeV has been presented and discussed.

Torrisi, L.; Cutroneo, M.; Ando, L. [Physics Department of Messina University, V.le F. S. D'Alcontres 31, 9816 S. Agata (Italy); Ullschmied, J. [Institute of Physics, ASCR, v.v.i., 182 21 Prague 8 (Czech Republic)

2013-02-15T23:59:59.000Z

440

Beam Dynamics for ARIA  

E-Print Network [OSTI]

Beam dynamics issues are assessed for a new linear induction electron accelerator being designed for flash radiography of large explosively driven hydrodynamic experiments. Special attention is paid to equilibrium beam transport, possible emittance growth, and beam stability. It is concluded that a radiographic quality beam will be produced possible if engineering standards and construction details are equivalent to those on the present radiography accelerators at Los Alamos.

Ekdahl, Carl

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam mass spectrometry" 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

Method for Characterization of Low Molecular Weight Organic Acids in Atmospheric Aerosols Using Ion Chromatography Mass  

E-Print Network [OSTI]

spectrometry (ESI-MS).17-19 ESI has the advantage of being compatible with polar mobile phases, and softMethod for Characterization of Low Molecular Weight Organic Acids in Atmospheric Aerosols Using Ion Chromatography Mass Spectrometry Lacey C. Brent,* Jessica L. Reiner, Russell R. Dickerson, and Lane C. Sander

Dickerson, Russell R.

442

Radiation Sources External Beam and Isotopes  

E-Print Network [OSTI]

Radiation Sources External Beam and Isotopes J. Daniel Bourland, PhD Professor Department of Radiation Oncology Departments of Physics and Biomedical Engineering Wake Forest School of Medicine Winston Radiation · Photons: electromagnetic radiation, no mass, E = h · X rays: origins are from atomic energy

443

ATA beam director experiment  

SciTech Connect (OSTI)

This report describes beam director elements for an experiment at the Advanced Test Accelerator. The elements described include a vernier magnet for beam aiming, an achromat magnet, and an isolation system for the beam interface. These components are built at small scale for concept testing. (JDH)

Lee, E.P.; Younger, F.C.; Cruz, G.E.; Nolting, E.

1986-06-23T23:59:59.000Z

444

Ion-radical synergy in HfO{sub 2} etching studied with a XeF{sub 2}/Ar{sup +} beam setup  

SciTech Connect (OSTI)

To gain more insight into fundamental aspects of the etching behavior of Hf-based high-k materials in plasma etch reactors, HfO{sub 2} films were etched in a multiple-beam setup consisting of a low energy Ar{sup +} ion beam and a XeF{sub 2} radical beam. The etch rate and etch products were monitored by real-time ellipsometry and mass spectrometry, respectively. Although etching of HfO{sub 2} in XeF{sub 2}/Ar{sup +} chemistry is mainly a physical effect, an unambiguous proof of the ion-radical synergistic effect for the etching of HfO{sub 2} is presented. The etch yield for 400 eV Ar{sup +} ions at a substrate temperature of 300 deg. C was 0.3 atoms/ion for Ar{sup +} sputtering and increased to 2 atoms/ion when XeF{sub 2} was also supplied. The etch yield proved to follow the common square root of ion energy dependence both for pure sputtering and radical enhanced etching, with a threshold energy at room temperature of 69{+-}17 eV for Ar{sup +} ions and 54{+-}14 eV for Ar{sup +} ions with XeF{sub 2}.

Gevers, P. M.; Beijerinck, H. C. W.; Sanden, M. C. M. van de; Kessels, W. M. M. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

2008-04-15T23:59:59.000Z

445

Neutral beam monitoring  

DOE Patents [OSTI]

Method and apparatus for monitoring characteristics of a high energy neutral beam. A neutral beam is generated by passing accelerated ions through a walled cell containing a low energy neutral gas, such that charge exchange neutralizes the high energy ion beam. The neutral beam is monitored by detecting the current flowing through the cell wall produced by low energy ions which drift to the wall after the charge exchange. By segmenting the wall into radial and longitudinal segments various beam conditions are further identified.

Fink, Joel H. (Livermore, CA)

1981-08-18T23:59:59.000Z

446

SIMULATION OF CLUSTER IMPACT INDUCED DESORPTION AND COOLING Surrey Ion Beam Centre  

E-Print Network [OSTI]

caused by a high energy C60 impact can eject a large polystyrene molecule without fragmentation spectrometry (SIMS) as a probing beam is showing great promise for the analysis of large organic molecules on ejection. Unlike the sputtering process this desorption process does not require that the binding energy

Webb, Roger P.

447

Ultra-high-resolution alpha spectrometry for nuclear forensics and safeguards applications  

SciTech Connect (OSTI)

We will present our work on the development of ultra-high-resolution detectors for alpha particle spectrometry. These detectors, based on superconducting transition-edge sensors, offer energy resolution that is five to ten times better than conventional silicon detectors. Using these microcalorimeter detectors, the isotopic composition of mixed-actinide samples can be determined rapidly without the need for actinide separation chemistry to isolate each element, or mass spectrometry to separate isotopic signatures that can not be resolved using traditional alpha spectrometry (e.g. Pu-239/Pu-240, or Pu-238/Am-241). This paper will cover the detector and measurement system, actinide source preparation, and the quantitative isotopic analysis of a number of forensics- and safeguards-relevant radioactive sources.

Bacrania, Minesh K [Los Alamos National Laboratory; Croce, Mark [Los Alamos National Laboratory; Bond, Evelyn [Los Alamos National Laboratory; Dry, Donald [Los Alamos National Laboratory; Moody, W. Allen [Los Alamos National Laboratory; Lamont, Stephen [Los Alamos National Laboratory; Rabin, Michael [Los Alamos National Laboratory; Rim, Jung [Los Alamos National Laboratory; Smith, Audrey [Los Alamos National Laboratory; Beall, James [NIST-BOULDER; Bennett, Douglas [NIST-BOULDER; Kotsubo, Vincent [NIST-BOULDER; Horansky, Robert [NIST-BOULDER; Hilton, Gene [NIST-BOULDER; Schmidt, Daniel [NIST-BOULDER; Ullom, Joel [NIST-BOULDER; Cantor, Robin [STAR CRYOELECTRONICS

2010-01-01T23:59:59.000Z

448

RAPID COMMUNICATIONS IN MASS SPECTROMETRY Rapid Commun. Mass Spectrom. 2005; 19: 25282538  

E-Print Network [OSTI]

the collision-induced decomposition spectra of ammoniated triglycerides as a function of fatty acid chain length of the collision-induced decomposition (CID) products of ammoniated TAGs (ammonium ion adducts) were examined corresponding to loss of that fatty acid. Mechanisms of the formation and decomposition of ammoniated TAGs

Evans, Jason

449

Bio-mass for biomass: biological mass spectrometry techniques for biomass fast pyrolysis oils.  

E-Print Network [OSTI]

??Biomass fast pyrolysis oils, or bio-oils, are a promising renewable energy source to supplement or replace petroleum-based products and fuels. However, there is a current… (more)

Dalluge, Erica A.

2013-01-01T23:59:59.000Z

450

Capillary LC Coupled with High-Mass Measurement Accuracy Mass Spectrometry  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New Substation Sites Proposed Route BTRICGEGR-N- EnergyDemonstration of Hyraxfor

451

Advanced Mass Calibration and Visualization for FT-ICR Mass Spectrometry  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUCProductstwrmrAre theAdministrator ReferencesalkaliAdvanced MagneticImaging. |

452

Matrixassisted laser desorption/ionization mass spectrometric analysis of aliphatic biodegradable photoluminescent polymers  

E-Print Network [OSTI]

established that the new ILMs provided good spottospot reproducibility and high ionization efficiency compared/ionization mass spectrometry (MALDIMS). The polymers, formed by a condensation reaction of three components

Yang, Jian

453

{sup 18}Ne production for the Beta beams project  

SciTech Connect (OSTI)

Intense relativistic (anti)neutrino beams are an unique tool required to study fundamental properties of neutrinos such as neutrino oscillation parameters, as well as their Majorana or Dirac nature, the lepton number conservation hypothesis and the absolute neutrino mass scale. Such beams originate from acceleration of ?-decaying radioactive ions (“Beta beams”). A molten fluoride salt target has been developed for the production of the required rates of low-Q baseline isotope {sup 18}Ne for the Beta beams project. The prototyped unit has been tested on-line at ISOLDE-CERN. In this contribution an overview of the prototyping and on-line tests is presented.

Hodák, Rastislav [Institute of Experimental and Applied Physics, CTU in Prague, Horská 3/22a, CZ-12800 Prague (Czech Republic); Mendonça, Tania M. [IFIMUP and IN - Institute of Nanosciences and Nanotechnologies, Rua do Campo Alegre 687, 4169-007 Porto, Portugal and CERN, CH-1211 Geneva 23 (Swaziland); Stora, Thierry [CERN, CH-1211 Geneva 23 (Switzerland)

2013-12-30T23:59:59.000Z

454

LBNL-46223, CBP Note 350 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS IN THE LHC  

E-Print Network [OSTI]

LBNL-46223, CBP Note 350 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS IN THE LHC M. A. Furman, W. C. Turner, Center for Beam Physics, LBNL, Berkeley, CA 94720, USA Abstract We present beam-beam simulation of simulations: (a) to as- sess undesirable effects from LBNL's luminosity monitor- ing scheme for the LHC [2

Furman, Miguel

455

LBNL-45363, CBP Note 333 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS  

E-Print Network [OSTI]

LBNL-45363, CBP Note 333 BEAM-BEAM SIMULATIONS FOR SEPARATED BEAMS Miguel A. Furman, Center for Beam Physics, LBNL, Berkeley, CA 94720 Abstract We present beam-beam simulation results from a strong undesirable effects from LBNL's sweeping lumi- nosity monitoring scheme for the LHC [1], and (b) to assess

Furman, Miguel

456

Airborne Gamma-Spectrometry in Switzerland  

SciTech Connect (OSTI)

Airborne gamma-spectrometry is able to obtain fast radiological information over large areas. The airborne gamma-spectrometry unit deployed in Switzerland by the Swiss National Emergency Operations Centre (NEOC) consists of a Swiss army Super Puma helicopter equipped with four NaI-Detectors with a total volume of 17 liters, associated electronics and a real-time data evaluation and mapping unit developed by the Swiss Federal Institute of Technology (ETH) and the Paul Scherrer Institut (PSI). The operational readiness of the airborne gamma-spectrometry system is validated in annual exercises of one week duration. Data from 2005 and 2006 exercises are represented in maps of {sup 137}Cs activity concentration for two towns located in southern and western Switzerland. An indicator of man-made radioactivity (MMGC ratio) is demonstrated for an area with four different types of nuclear installations. The intercomparison between airborne gamma-spectrometry and ground measurements showed good agreement between both methods.

Butterweck, Gernot [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Bucher, Benno [Swiss Federal Nuclear Safety Inspectorate, 5232 Villigen HSK (Switzerland); Rybach, Ladislaus [Swiss Federal Institute of Technology Zurich, Institute of Geophysics, 8093 Zurich (Switzerland)

2008-08-07T23:59:59.000Z

457

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

SciTech Connect (OSTI)

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

458

Atom penetration from a thin film into the substrate during sputtering by polyenergetic Ar{sup +} ion beam with mean energy of 9.4 keV  

SciTech Connect (OSTI)

Penetration of alien atoms (Be, Ni) into Be, Al, Zr, Si and diamond was investigated under Ar{sup +} ion bombardment of samples having thermally evaporated films of 30--50 nm. Sputtering was carried out using a wide energy spectrum beam of Ar{sup +} ions of 9.4 keV to dose D = 1 {times} 10{sup 16}--10{sup 19} ion/cm{sup 2}. Implanted atom distribution in the targets was measured by Rutherford backscattering spectrometry (RBS) of H{sup +} and He{sup +} ions with energy of 1.6 MeV as well as secondary ion mass-spectrometry (SIMS). During the bombardment, the penetration depth of Ar atoms increases with dose linearly. This depth is more than 3--20 times deeper than the projected range of bombarding ions and recoil atoms. This is a deep action effect. The analysis shows that the experimental data for foreign atoms penetration depth are similar to the data calculated for atom migration through the interstitial site in a field of internal (lateral) compressive stresses created in the near-surface layer of the substrate as a result of implantation. Under these experimental conditions atom ratio r{sub i}/r{sub m} (r{sub i} -- radius of dopant, r{sub m} -- radius target of substrate) can play a principal determining role.

Kalin, B.A.; Gladkov, V.P.; Volkov, N.V.; Sabo, S.E. [Moscow Engineering Physics Inst. (Russian Federation)

1995-12-31T23:59:59.000Z

459

Broad beam ion implanter  

DOE Patents [OSTI]

An ion implantation device for creating a large diameter, homogeneous, ion beam is described, as well as a method for creating same, wherein the device is characterized by extraction of a diverging ion beam and its conversion by ion beam optics to an essentially parallel ion beam. The device comprises a plasma or ion source, an anode and exit aperture, an extraction electrode, a divergence-limiting electrode and an acceleration electrode, as well as the means for connecting a voltage supply to the electrodes.

Leung, Ka-Ngo (Hercules, CA)

1996-01-01T23:59:59.000Z

460

Small beam nonparaxiality arrests selffocusing of optical beams Gadi Fibich  

E-Print Network [OSTI]

Small beam nonparaxiality arrests self­focusing of optical beams Gadi Fibich Department­focusing in the presence of small beam nonparaxiality is derived. Analysis of this equation shows that nonparaxiality remains small as the beam propa­ gates. Nevertheless, nonparaxiality arrests self­focusing when the beam

Soatto, Stefano

Note: This page contains sample records for the topic "beam mass spectrometry" from the National Library of EnergyBeta (NLEBeta).
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461

Piezoelectric energy harvester having planform-tapered interdigitated beams  

DOE Patents [OSTI]

Embodiments of energy harvesters have a plurality of piezoelectric planform-tapered, interdigitated cantilevered beams anchored to a common frame. The plurality of beams can be arranged as two or more sets of beams with each set sharing a common sense mass affixed to their free ends. Each set thus defined being capable of motion independent of any other set of beams. Each beam can comprise a unimorph or bimorph piezoelectric configuration bonded to a conductive or non-conductive supporting layer and provided with electrical contacts to the active piezoelectric elements for collecting strain induced charge (i.e. energy). The beams are planform tapered along the entirety or a portion of their length thereby increasing the effective stress level and power output of each piezoelectric element, and are interdigitated by sets to increase the power output per unit volume of a harvester thus produced.

Kellogg, Rick A. (Tijeras, NM); Sumali, Hartono (Albuquerque, NM)

2011-05-24T23:59:59.000Z

462

Extending Penning trap mass measurements with SHIPTRAP to the heaviest elements  

SciTech Connect (OSTI)

Penning-trap mass spectrometry of radionuclides provides accurate mass values and absolute binding energies. Such mass measurements are sensitive indicators of the nuclear structure evolution far away from stability. Recently, direct mass measurements have been extended to the heavy elements nobelium (Z=102) and lawrencium (Z=103) with the Penning-trap mass spectrometer SHIPTRAP. The results probe nuclear shell effects at N=152. New developments will pave the way to access even heavier nuclides.

Block, M.; Ackermann, D.; Herfurth, F.; Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Blaum, K. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg, Germany and Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Droese, C.; Marx, G.; Schweikhard, L. [Ernst-Moritz-Arndt-Universitaet, 17487 Greifswald (Germany); Duellmann, Ch. E. [Johannes Gutenberg-Universitaet, 55099 Mainz, Germany and GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt, Germany and Helmholtz-Institut Mainz, 55099 Mainz (Germany); Eibach, M. [Ruprecht-Karls-Universitaet, 69120 Heidelberg, Germany and Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Eliseev, S. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Haettner, E.; Plass, W. R.; Scheidenberger, C. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt, Germany and Justus-Liebig-Universitaet, 35392 Giessen (Germany); Hessberger, F. P. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt, Germany and Helmholtz-Institut Mainz, 55099 Mainz (Germany); Ramirez, E. Minaya [Helmholtz-Institut Mainz, 55099 Mainz, Germany and GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Nesterenko, D. [Petersburg Nuclear Physics Institute, Gatchina, 188300 St. Petersburg (Russian Federation); and others

2013-03-19T23:59:59.000Z

463

Method and apparatus for measuring the momentum, energy, power, and power density profile of intense particle beams  

DOE Patents [OSTI]

A method and apparatus for determining the power, momentum, energy, and power density profile of high momentum mass flow. Small probe projectiles of appropriate size, shape and comp