Gas chromatography - mass spectroscopy

Because the flavonoid glycosides are non-volatile, GC has not routinely been used for flavonoid analysis. However, Greaser et al. (1992) have developed a method to analyze the hydrolyzed flavanone content by GC-MS. The method involves solvent extraction of the tissues, hydroylsis of the flavonoids to their respective aglycones, trimethylsilation, and analysis by GC-MS. While the method will accurately identify and quantify the flavonoid aglycones present in the sample, it cannot determine the relative amounts of the neohesperidosides and rutinosides, and would therefore only be able to give an estimation of the amount of bitter flavonoids in a sample. 

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Acrylonitrile in both biological and environmental samples is most commonly determined by gas chromatography with a nitrogen-phosphorus detector (GC/NPD) (Page 1985), gas chromatography/flame ionization detection (GC/FID) (EPA 1982a), or gas chromatography/mass spectroscopy (GC/MS) (Anderson and Harland 1980). Infrared spectroscopy (Jacobs and Syrjala... 

Gas chromatography-mass spectroscopy is used to obtain extensive compositional information on rubbers. It can identify minor components of the sample such as the breakdown products of the cure system and the antidegradants. 

Niessen WMA, ed. Current Practice of Gas Chromatography-Mass Spectroscopy. New York Marcel Dekker 2001. 

Schulten H-F, Schnitzer M. Structural studies on soil humic acids by Curie-point pyrolysis-gas chromatography/mass spectroscopy. Soil Sci. 1992 153 205-224. 

Although the metabolism of several phthalate esters has been studied in vitro, essentially all of the in vivo studies have involved DEHP. A summary of these experiments which involved exposure offish to aqueous - C-DEHP is presented in Table IV (11,12). Tissue C was isolated and separated into parent and the various metabolites by preparative thin layer chromatography on silica gel. Metabolites were hydrolyzed where appropriate and identified by gas chromatography-mass spectroscopy. In whole catfish, whole fathead minnow and trout muscle, the major metabolite was the monoester while in trout bile the major metabolite was the monoester glucuronide. The fact that in all cases the major metabolite was monoester or monoester glucuronide despite the differences in species, exposure level and duration, etc. represented by these data, suggests that hydrolysis of DEHP to monoester is important in the biotransformation of DEHP by fish. 

Mule SJ, Casella GA. (1988). Rendering the "poppy-seed defense" defenseless identification of 6-monoacetylmorphine in urine by gas chromatography/mass spectroscopy. Clin Chem. July 34 7 1427-30. 

Lamey SC, Hesbach PA, White KD. 1991. Liquid fuel analyses using high-performanee liquid chromatography and gas chromatography-mass spectroscopy. Energy and Fuels 5 222-226. 

Isolation and identification of pyrazine alkaloids (Table III) have been achieved in most cases by a combination of gas chromatography and mass spectrometry (35,36,38,69,97,142). Methyl-, 2,3,6-trimethyl-, and tetramethylpyrazines (23a, 21a, and 22a) from the melon fly are identified by utilizing a solid sampling technique in conjunction with gas chromatography-mass spectroscopy (147). Methylpyrazines show the molecule ion as a base peak. Fragmentation proceeds mainly by the loss of HCN or CH3CN from the molecular ion (141). Eth-... 

Nishimura, O. Identification of the characteristic odorants in fresh rhizomes of ginger (Zingiber officinale Roscoe) using aroma extract dilution analysis and modified multidimensional gas chromatography-mass spectroscopy. J Agr Food Chem 1995 43(11) 2941-2945. 

Munson, J. W., and Abdine, H., "Determination of N-Nitroso-nornicotine in Tobacco by Gas Chromatography/Mass Spectroscopy", Analytical Letters, 1977, 10f 777-786. 

Tetlow VA Merrill J (1996). Rapid determination of amphetamine stereoisomer ratios in urine by gas chromatography-mass spectroscopy. Annals of Clinical Biochemistry, 33, 50-4... 

One determines the overall reaction by using some of the many tools of chemical analysis. Coulometeiy, gas chromatography, mass spectroscopy, and, in complex cases, computerized pattern-recognition programs applied to GC-MS data (see Section 7.5.19) are the typical tools used in determining the overall reaction. The current efficiency for the reaction concerned is important here and may vaty with potential. 

Bechtold, W.E., Strunk, M.R., Thomton-Maiming, J.R. Henderson. R.F. (1995) Analysis of butadiene, butadiene monoxide, and butadiene diepoxide in blood by gas chromatography/ gas chromatography/mass spectroscopy. Chem. Res. Toxicol., 8, 182—187... 

Fig. 2. Separation and analysis of polyaromatic sulfur-containing compounds (PASC). Oils 3-1, 3-2, and 3-3 were analyzed by gas chromatography-mass spectroscopy (GC-MS) and gas chromatography-atomic emission detection (GC-AED). Reproduced from Ref. 12, with permission.

With today s advanced analytical procedures, it is possible to describe the composition of these fuels in considerable detail. By combining several sequenced liquid chromatographic separations with gas chromatography-mass spectroscopy and by using specific gas chromatographic detectors for sulfur compounds, it has been possible to identify the majority of individual sulfur species in some fuels (12-19). A typical separation scheme is shown... 

ANALYTICALMETHODS - HYPHENATED INSTRUMENTS] (Vol 2) Gas chromatography-mass spectroscopy... 

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