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Your search keyword '"Lee, Edgar"' showing total 5 results
Start Over Author "Lee, Edgar" Topic gas chromatography
5 results on '"Lee, Edgar"'

1. Volatile and semivolatile compound screening of cocoa raw materials and finished chocolate products using headspace SPME-GC-TMS

Author

Bowerbank, Christopher R., McShea, Andrew, Munro, Sandra B., Lee, Edgar D., and Later, Douglas W.

Subjects
Cacao -- Chemical properties, Cacao -- Research, Gas chromatography
Abstract

Solid phase microextraction (SPME) was used to generate volatile and semivolatile compound profiles of raw materials used in the production of chocolate products. The headspace of cocoa beans, cocoa butter, [...]

Published
2009

2. The Applicability of Field-Portable GC-MS for the Rapid Sampling and Measurement of High-Boiling-Point Semivolatile Organic Compounds in Environmental Samples.

Author

Tai Van Truong, Porter, Nathan L., Lee, Edgar D., and Thomas, Robert J.

Subjects
GAS chromatography/Mass spectrometry (GC-MS), GAS chromatography, LABORATORY techniques, MASS spectrometry, SEMIVOLATILE organic compounds
Abstract

In this study, we report on the use of field-portable gas chromatography-mass spectrometry (GCMS) with solid-phase microextraction, purge-and-trap, thermal desorption, and heated headspace sampling techniques to provide a fast response for in-field analysis of semivolatile organic compounds (SVOCs) in a wide variety of environmental-type samples including potable waters, tea, plants, and road gravel. We demonstrate that this field-portable approach can provide the required sensitivity and selectivity for the effective analysis of SVOCs with very high boiling points such as polycyclic aromatic hydrocarbons (PAHs), pesticides, phenolic compounds, and phthalate esters in a number of different field-based samples, in less than 10 min. [ABSTRACT FROM AUTHOR]

Published
2016

3. Person-Portable GC-MS for Rapid On-Site Environmental Screening of Contaminants in Drinking Water.

Author

Wirth, Tiffany C., Later, Jakob B., Oliphant, Joseph L., Lee, Edgar D., and Later, Douglas W.

Subjects
HALOCARBON analysis, GAS chromatography, MASS spectrometry, WATER pollution, WATER supply, PRODUCT design, MEDICAL equipment reliability
Abstract

The article discusses the methods of rapidly detecting contaminants such as trihalomethanes (TMH) in drinking water using a person-portable gas chromatograph-mass spectrometer. TMHs are considered an environmental pollutant and are carcinogenic. The CUSTODION SPME (solid phase microextraction) has a short cycle time between injections which allows the user to quickly analyze samples on-site with high sensitivity and specificity, therefore, it can be used for field screening of water samples.

Published
2012

4. Rapid Field Detection of Chemical Warfare Agents, Simulants, By-Products, and Precursors Using Solid Phase Microextraction and Portable GC-TMS.

Author

Bowerbank, Christopher R., Wirth, Tiffany C., Lee, Edgar D., and Later, Douglas W.

Subjects
SPECTRUM analysis instruments, MASS spectrometers, GAS chromatography, CHROMATOGRAPHIC analysis, CHEMICAL warfare
Abstract

The article discusses the determination of chemical warfare agents (CWAs), CWA simulants, by-products, and precursor with the use of solid phase microextraction and portable capillary gas chromatography toroidal ion trap mass spectrometer (GC-TMS). It notes the identification of low concentrations of CWAs, and low to neat concentrations of CWA precursors. It stresses the application of the CUSTODIAN SPME syringe and GUARDION -7 GC-TMS being suited for the screening of CWAs.

Published
2009

5. Use of a hand-portable gas chromatograph–toroidal ion trap mass spectrometer for self-chemical ionization identification of degradation products related to O-ethyl S-(2-diisopropylaminoethyl) methyl phosphonothiolate (VX)

Author

Smith, Philip A., Lepage, Carmela R. Jackson, Savage, Paul B., Bowerbank, Christopher R., Lee, Edgar D., and Lukacs, Michael J.

Subjects
*GAS chromatography, *ION traps, *CHEMICAL ionization mass spectrometry, *ORGANOTHIOPHOSPHORUS compounds, *BIODEGRADATION, *CHEMICAL warfare agents
Abstract

Abstract: The chemical warfare agent O-ethyl S-(2-diisopropylaminoethyl) methyl phosphonothiolate (VX) and many related degradation products produce poorly diagnostic electron ionization (EI) mass spectra by transmission quadrupole mass spectrometry. Thus, chemical ionization (CI) is often used for these analytes. In this work, pseudomolecular ([M+H]+) ion formation from self-chemical ionization (self-CI) was examined for four VX degradation products containing the diisopropylamine functional group. A person-portable toroidal ion trap mass spectrometer with a gas chromatographic inlet was used with EI, and both fixed-duration and feedback-controlled ionization time. With feedback-controlled ionization, ion cooling (reaction) times and ion formation target values were varied. Evidence for protonation of analytes was observed under all conditions, except for the largest analyte, bis(diisopropylaminoethyl)disulfide which yielded [M+H]+ ions only with increased fixed ionization or ion cooling times. Analysis of triethylamine-d 15 provided evidence that [M+H]+ production was likely due to self-CI. Analysis of a degraded VX sample where lengthened ion storage and feedback-controlled ionization time were used resulted in detection of [M+H]+ ions for VX and several relevant degradation products. Dimer ions were also observed for two phosphonate compounds detected in this sample. [Copyright &y& Elsevier]

Published
2011
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