Gas liquid chromatographic analysis

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... 

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. 

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. 

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. 

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. 

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. 

We have also studied polysaccharide deposition processes during cell wall formation (7), by gas-liquid chromatographic analysis of fractions sep-... 

Gas-liquid chromatographic analysis with a 1 S-m 5% SE-30 column at 13S° b Could not be separated by gas chromatography... 

ACETYLATION. Acetylation of the residue may be carried out using 1 cm3 of acetic anhydride and incubating at 100°C for 1 hr, or acetyl chloride at 60°C for 15 min in a capped tube. When the acetyl chloride is used, the residue in the tube is rinsed down with 0.5 cm3 of benzene and 0.5 cm3 of the acetyl chloride is added. Stopper and heat at 60°C for 15 min. After either reaction is complete, the reaction mixture is evaporated to dryness under dry N2 in a water bath at 40°C. The walls are rinsed down with 0.5 cm3 of chloroform and evaporated to dryness. The residue is dissolved in 0.1 or 0.2 cm3 of CS2 for gas-liquid chromatographic analysis. 

To acylate the n-butyl esters, 60 yl of CH2Cl2 and 20 yl of TFAA are added, then mixed with ultrasound and heated at 150°C for 5 min in an oil bath. The samples are then ready for gas-liquid chromatographic analysis. 

Gas-liquid Chromatographic analysis) 44)G.B.Marini-Bettolo, Chim e Ind (Milano)... 

JJ Ryan, JF Lawrence. Comparison of electron-capture and electrolytic conductivity detector for the gas-liquid chromatographic analysis of some perfluoro derivatives of four agriculture chemicals. J Chromatogr 135 117-122, 1977. 

A.G. Kelso, The Importance of Sample Environment in the Gas liquid Chromatographic Analysis of Trinitrotoluene ,... 

S3S) Camera, E., Pravisani, D., Ohman, V. Gas-liquid chromatographic analysis of mixtures of nitric esters with nitro compounds. Explosivstoffe 13, 237 (1965). —... 

J. R. Watson and R. C. Lawrence, Specific quantitative gas-liquid chromatographic analysis of methyldopa and some foreign related amino acids in raw material and commercial tablet, J. Chromatogr., 103 63 (1975). 

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