Liquid gas chromatograph

Chlorooctane (14 9 g, 0 I mol), potassium fluoride dihydrate (47 g, 0 5 mol), hexadecyltributylphosphonium bromide (5 1 g, 0 01 mol), and water (30 mL) are mixed in an autoclave equipped with a magnetic stirrer and heated to 160 °C (bath temperature) for 7 h After this time gas-liquid chromatographic analysis (10% Carbowax 20M on Chromosorb) shows a 95% conversion to a mixture of 1-fluorooctane (82%), octenes (6%), and 1-octanol (7%) The organic layer is separated, washed with water, washed with concentrated sulfuric acid, washed once again with water, dried over calcium chloride, and distilled to give 10 g (77%) of ] -fluorooctane... 

Acylation of various oxygen functions by use of common and commercially available fluonnated carboxylic acid denvatives such as trifluoroacetic anhydride or the corresponding acyl halides have already been discussed sufficiently in the first edition [10] Therefore only exceptional observations will be described in this section In the past 15 years, many denvatizations of various nonfluonnated oxygen compounds by fluoroacylation were made for analytical purposes. Thus Mosher s acid chlorides for example became ready-to-use reagents for the determination of the enantiomeric purity of alcohols and amines by NMR or gas-liquid chromatographic (GLC) techniques [//] (equation 1)... 

Jaglan PS, March RB, Fukuto TR, et al. 1970. Gas-liquid chromatographic determination of methyl parathion and metabolites. J Agric Food Chem 18 809-813. 

Shafik TM, Bradway DE, Enos HR, et al. 1973a. Human exposure to organophosphorus pesticides A modified procedure for the gas-liquid chromatographic analysis of alkylphosphate metabolites in urine. J Agr Food Chem 21 625-629. 

Pokharkar DS, Dethe MD. 1981. Gas-liquid chromatographic studies on residues of endosulfan on chili fruits. J Environ Sci Health B16 439-451. 

Wilkes PS. 1981. Gas-liquid chromatographic-mass spectrometric confirmation of endosulfan and endosulfan sulfate in apples and carrots. J Assoc Off Anal Chem 64 1208-1210. 

Based on gas-liquid chromatographic (GLC) or GLC-mass spectrophotometric analysis. 

S. W., Melton, C. M. Estimation of gas-liquid chromatographic retention times from molecular structure.. Chromatogr. A 1994, 662, 269-280. 

Tokunaga R, Takahata S, Onoda M, Ishi-i T, Sato K (1974) Evaluation of the exposure to organic solvent mixture. Comparative studies on detection tube and gas-liquid chromatographic methods, personal and stationary sampling, and urinary metabolite determination. Internationales Archiv Arbeitsmedizin 33 257-267. 

Deo PD, Howard PH. 1978. Combined gas-liquid chromatographic mass spectrometric analysis of some commercial aryl phosphate oils. J Assoc Off Anal Chem 61 266-270. 

Lombardo P, Egry IJ. 1979. Identification and gas-liquid chromatographic determination of aryl phosphate residues in environmental samples. J Assoc Off Anal Chem 62 47-51. 

A gas liquid chromatographic assay for determining the quantity and composition of fatty acids is based on conversion of the acids by means of CDI with methanol, ethanol, trifluoroethanol, pentafluoropropanol, or heptafluorobutanol into the corresponding esters. The alcohols in question were chosen because of the short retention times of their esters.1333... 

A gas liquid chromatographic (GLC) method was described for determining residues of Bayer 73 (2-aminoethanol salt of niclosamide) in fish muscle, aquatic invertebrates, mud, and water by analyzing for 2-chloro-4-nitroaniline, a hydrolysis product of Bayer 73 [83]. Residues were extracted with acetone-formic acid (98 + 2), and partitioned from water samples with chloroform. After sample cleanup by solvent and acid base partitioning, the concentrated extract was hydrolyzed with 2N NaOH and H202 for 10 min at 95°C. The 2-chloro-4-nitroaniline was then partitioned hexane ethyl ether (7 + 3) and determined by electron capture GLC. Average recoveries were 88% for fish, 82% for invertebrates, 82% for mud, and 98% for water at 3 or more fortification levels. 

Patrick, M., Koning, A. J. and Smith, A. B. (1985) Gas liquid chromatographic analysis of fatty acids in food residues from ceramics found in the Southwestern Cape. Archaeomtery 27, 231 236. 

Many gas-liquid chromatographic methods for determination of valproic acid in biological fluids have been reported. 

Recently, most of the methods which have been used for the analysis of valproic acid in plasma, serum, cerebral spinal fluid, saliva, breast milk, and urine involve acidification of the biological sample, extraction into an organic solvent, and direct injection onto a gas-liquid chromatographic column (28, 29, 16, 30, 31, 32,... 

The preparation of volatile derivatives of carbohydrates has permitted the development of useful gas-liquid chromatographic analyses... 

Procedures for determining fatty acids in sediments involved liquid-liquid extraction, liquid-solid adsorption chromatography followed by gas liquid chromatographic analysis [10-12], Liquid extractions have been performed with methanol-chloroform [13], methylene chloride [14] and benzene-methanol [15, 16]. Typical liquid-solid adsorbents are silicic acid. Standard gas chromatographic separations for complex mixtures employ non-polar columns packed with OV-1, OV-17, OV-101, SE-30, or glass capillary columns containing similar phases. 

An official gas chromatographic method [29] is available from the determination of volatile fatty acids in sewage sludge. This method is based on gas liquid chromatographic estimation with a flame ionization detector, and is applicable up to 2000mg total volatile fatty acids per litre, while the concentrations of individual fatty acids can also be determined. Where this method is not practicable an empirical method based on the spectrophotometric determination of ferric hydroxamates can be used, giving a value for total fatty acids expressed as acetic acid. For control purposes a rapid test is described in which the volatile fatty acids are determined by electrometric titrimetry on the neutralized sludge obtained from the determination of alkalinity. 

Oxamyl added at 0.2-0.40mg kg-1 level to 50g of sample. tDuplicate injections into the gas-liquid chromatograph of extract from each sample... 

Caille G, Plaa GL, Vezina M. 1987. Gas-liquid chromatographic determination of chlordecone and mirex in biological specimens. J Toxicol Clin Exp 7(1) 21-29. 

Norstrom RJ, Won HT, Holdrinet MVH, et al. 1980a. Gas-liquid chromatographic determination of mirex and photomirex in the presence of polychlorinated biphenyls Interlaboratory study. J Assoc Off Anal Chem 63(1) 37-42. 

Stein VB, Pittman KA. 1979. Gas-liquid chromatographic determination of mirex in plasma, liver and fat from mice and monkeys. Bull Environ Contam Toxicol 23(3) 300-305. 

The minor (R,S) diastereomer is present in the crude reaction mixture to the extent of approximately 0.9% as determined by capillary gas-liquid chromatographic analysis performed on a Hewlett-Packard 5790A gas chromatograph equipped with a Hewlett-Packard 3390A integrator and HP-1 methylsilicone gum column (25 m x 0.2 mm x 0.33 pm film thickness). The checkers found that HPLC analysis (Zorbax SB-Phenyl column 25 cm x 4.6 mm, 40 60 MeCN/0.1% aqueous phorphoric acid, 1.5 mL/min, 250 nm detection) provided satisfactory resolution of the R,R- and R,S-diastereomers. The minor diastereomer is hardly discernible by 1H NMR (500 MHz) after purification by flash chromatography. 

Young, C.L. Cruickshank, A.J.B. Gainey, B.W. Hicks, C.P. Letcher, T.M. Moody, R.W. Gas-Liquid Chromatographic Determination of Cross-Term Second Virial Coefficients using Glycerol, Trans. Far. Soc., 65, 1014(1969). 

Szeto SY, Brown MJ. 1982. Gas-liquid chromatographic methods for determination of disulfoton, phorate, oxydemeton-methyl and their toxic metabolites in asparagus tissue and soil. J Agric Food Chem 30 1082-1086. 

Analytical Procedures. Incubation mixtures were extracted with diethyl ether except in the case of toxaphene where a mixture of chloroform-methanol (5 1, v/v) was used instead. Ether extracts of DDT, dieldrin, and lindane were dried over anhydrous sodium sulfate, evaporated using a gentle stream of nitrogen, and the residues were redissolved in n-hexane. Aliquots of the hexane solutions were directly injected into a gas liquid chromatograph (GLC, Varian, model 240 ) equipped with an electron capture (EC) detector (Aerograph Sc H detector) and a 1.5% 0V-101 on chrom GHP 100/120, 5 x 1/8" stainless steel column. The detector temperature was 245°C, injection port 235°C, and the oven temperature was 125°C for lindane, 180°C for DDT and 200°C for dieldrin. Carrier gas was nitrogen at the flow rate of 40 ml/min. 

Bombardelli, E., Bonati, A., Gabetta, B., and Martinelli, E. M. (1980). Gas-liquid chromatographic method for the determination of ginsenosides in Panax ginseng.. Chroma-togr. 196,121-132. 

Janini, GM., Johnston, K., and Zielinski, W.L., Use of a nematic liquid-crystal for gas-liquid-chromatographic separation of poly aromatic hydrocarbons, Anal Chem., 47, 670, 1975. 

Janini, GM., Muschik, G.M., Schroer, J.A., and Zielinski, W.L., Gas-liquid-chromatographic evaluation and gas-chromatography mass spectrometric application of new high-temperature hquid-crystal stationary phases for polycyclic aromatic hydrocarbon separations. Ana/. Chem., 4S, 1879, 1976. 

Blake JW, Ray RS, Noonan JS, Murdick PW. 1974. Rapid, sensitive gas—liquid Chromatographic screening procedure for cocaine. Anal Chem 46 288. 

Cellular component or artifact- Gas-liquid chromatographic fatty acid... 

Grob, K., and G. Grob. Gas-liquid chromatographic-mass spectrometric investigation of Cf-Cto organic compounds in an urban atmosphere. An application of ultra trace analysb on capillary columns. J. Chromatogr. 62 1-13, 1972. 

Anderson, M.A. Influence of surfactants on vapor-liquid partitioning. Environ. Sci. Technol, 26(11) 2186-2191,1992. Anderson, R.J., Anderson, C.A., and Olson, T.J. A Gas-liquid chromatographic method for the determination of trichlorfon in plant and animal tissues, J. Agric. Food Chem., 14(5) 508-512, 1966. 

Krause, A.A. and Niemczyk, H.D. Gas-liquid chromatographic analysis of chlorthal-dimethyl herbicide and its degradates in turfgrass thatch and soil using a solid-phase extraction technique, J. Environ. Sci Health, B25(5) 587-606, 1990. Kresheck, G.C., Schneider, H., and Scheraga, H.A. The effect of DzO on the thermal stability of proteins. Thermod3mamic parameters for the transfer of model compounds from HzO to DzO, J. Phys. Chem., 69(9) 3132-3144, 1965. 

Suffet, I.H., Faust. S.D., and Carey, W.F. Gas-liquid chromatographic separation of some organophosphate pesticides, then-hydrolysis products, and oxons. Environ. Sci. Technoi, l(8) 639-643, 1967. 

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