Gas chromatography detection

Reference methods for criteria (19) and hazardous (20) poUutants estabHshed by the US EPA include sulfur dioxide [7446-09-5] by the West-Gaeke method carbon monoxide [630-08-0] by nondispersive infrared analysis ozone [10028-15-6] and nitrogen dioxide [10102-44-0] by chemiluminescence (qv) and hydrocarbons by gas chromatography coupled with flame-ionization detection. Gas chromatography coupled with a suitable detector can also be used to measure ambient concentrations of vinyl chloride monomer [75-01-4], halogenated hydrocarbons and aromatics, and polyacrylonitrile [25014-41-9] (21-22) (see Chromatography Trace and residue analysis). 

The catalyst was prepared from a nickel-aluminum (50 50) alloy using the procedure given by Mozingo. The catalyst is used in large excess. Reduced amounts of catalyst resulted in decreased yields, and the product is contaminated with detectable (gas chromatography) amounts of bis(4-methoxyphenyl) telluride. 

For the detection, gas chromatography (GC) [15,18-20, 28] and liquid chromatography (LC) [14—16, 21, 22, 24, 26-29] coupled with mass spectrometry (MS) or tandem mass spectrometry (MS/MS) have been the techniques most frequently used in the determination of pesticides in ground water. Examples of the application of both techniques in the area of study, Catalonia, are the work of Garrido et al. [17], who used GC-MS and GC with electron capture detection (ECD) for the analysis of 44 pesticides in groundwater samples from Catalonia and that of Kampioti et al. [25], who used online SPE-LC-MS/MS to analyse 20 pesticides in river water and... 

Hydrocarbon Anomalies in Soils Soil samples were collected at 200 to 500 m intervals over the Lisbon and Lightning Draw fields and analyzed for thermally desorbed Ci to C12 alkanes by Flame Ionization Detection Gas Chromatography (GC-FID) and solvent-extractable Ce to C36 aromatics by UV-fluorescence spectrophotometry. 

Mugo, R.K. and Orians, K.J. (1993) Seagoing method for the determination of chromium (III) and total chromium in sea water by electron-capture detection gas chromatography. Anal. Chim. Acta, 271, 1-9. 

Uchida et al. [793] determined various selenium species in river water and sea water by electron capture detection gas chromatography after reaction with l,2-diamino-3,5-dibromobenzene. This reagent reacts with seleniumflV) to form 4,6-dibromopiazselenol which is extracted into toluene. After Se(-ll) and Se(0) has been reduced by a bromine-... 

Tsai reviewed the separation methods used in the determination of choline and acetylcholine [10]. This review surveyed the array of analytical techniques that have been adopted for the measurement of acetylcholine or its main precursor/metabolite (choline), ranging from simple (bioassay, radio enzymatic assay, gas chromatography-flame ionization detection, gas chromatography-mass spectrometry, high... 

Clark Al, McIntyre AE, Lester JN, et al. 1984. A comparison of photoionisation detection gas chromatography with a Tenax GC sampling tube procedure for the measurement of aromatic hydrocarbons in ambient air. J Environ Anal Chem 17 315-326. 

Modern tHcy methods include enzyme immunoassays and chromatographic-based methods. In practice, immunoassays " are most often used for routine purposes (e.g., fluorescence polarization immunoassay IFPIA] as run on Abbott s IMx and AxSYM platforms) Chromatographic assays include amino acid analysis high-performance liquid chromatography (HPLC) with ultraviolet, fluorescence, or electrochemical detection ° " capillary electrophoresis with fluorescence detection gas chromatography-mass spectrometry (GC-MS) and liquid chromatography with tandem MS (MS-MS). 

Since methloninase has potential applications in both aerobic and anaerobic food systems, a number of experiments were conducted to characterize and evaluate the performance of methloninase under a variety of these conditions. In these studies freeze-dried methloninase preparations (either 0.779 units/mg protein or 2.45 units/mg protein) were employed for generation of methanethiol, and selective flame photometric detection gas chromatography was use for quantifying methanethiol. The column was a 3 m x 4 mm id glass column packed with Carbopak BHT-100, and It was operated at 60°C isothermally for methanethiol analysis. When higher molecular weight sulfur compounds were measured also (e.g.,... 

Cohen G. (1993) The analysis of sulfur compounds in coffee aroma by sulfur chemiluminescence detection-gas chromatography. 15th Int. Colloq. Chem. Coffee (Montpellier, 6-11.6.1993) (ASIC, 1993) 2, 528-36. 

Water samples collected from the ocean are measured for CFCs and CCI4 using an electron capture detection gas chromatography system. Analysis of water samples is done onboard ship, usually within hours of collection. The unit of measure is pmol kg or 10 moles kg . These are extremely low level concentrations that are easily susceptible to... 

Human Peripheral Blood Using Gas-Liquid Chromatography with Electron Capture Detection Gas Chromatography of Steroids in Biological Fluids, edited by M. B. Lipsett, Plenum Publishing Corp., New York, 1965, pp. 153-168... 

An Improved Method for the Quantitation of Phencyclidine (PCP) in Biological Samples Utilizing Nitrogen-Detection Gas Chromatography... 

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