Nitrogen gas chromatography

Plant samples are homogenized with sodium hydrogencarbonate aqueous solution to prevent decomposition of the analytes during homogenization. Imibenconazole and its primary metabolite, imibenconazole-debenzyl, are extracted from plan materials and soil with methanol. After evaporation of methanol from the extracts, the residues are extracted with dichloromethane from the residual aqueous solution. The dichloromethane phase is cleaned up on Florisil and Cig columns. Imibenconazole and imibenconazole-debenzyl are determined by gas chromatography/nitrogen-phosphorus detection (GC/NPD). 

Mepanipyrim in crop samples is recovered by acetone solvent extraction. The acetone is evaporated under reduced pressure and the residual aqueous extract is hydrolyzed with enzyme (jS-glucosidases) to release hydroxylated metabolite(s). After enzyme treatment, mepanipyrim and the propanol form metabolite are extracted with dichloromethane, purified by silica gel column chromatography and quantified by gas chromatography/nitrogen-phosphoms detection (GC/NPD). 

Water samples are directly partitioned with dichloromethane (DCM). The DCM exAact is then rotary evaporated and driven to dryness with a sAeam of niAogen. The dry residue is dissolved in acetone and analyzed by gas chromatography/nitrogen-phosphorus detection (GC-NPD). 

A Multi-residue analytical method (for plants) is used for rice, citrus and tomato. Buprofezin and p-OH-buprofezin (as the acetylated derivative, p-AcO-buprofezin) are analyzed simultaneously using gas chromatography/nitrogen-phosphorus detection (GC/NPD). 

Abbreviations (iC/l ID, gas chromatography/flame ionization detection GC/MS, gas chromatogra-phy/mass spectrometry GC/NPD, gas chromatography/nitrogen-phosphorus detection... 

Gascon, J. and D. Barcelo (1994). Rapid magnetic particle-based ELISA assay compared with gas chromatography-nitrogen phosphorous detectin for determining atrazine in freeze-dried water samples. Chromatographia, 38 633-636. 

Gascon, J., G. Durand, and D. Barcelo (1995b). Pilot survey for atrazine and total chlorotriazines in estuarine waters using magnetic particle-based immunoassay and gas chromatography-nitrogen phosphorous detection. Environ. Sci. Technol., 29 1551-1556. 

It is unlikely that the unchanged nerve agent would be detected in the blood or tissues of a casualty unless samples were collected very soon after the exposure. A number of methods have been reported for the analysis of nerve agents in blood, for application to animal studies. These involve simple liquid or SPE extraction, for example, using chloroform (sarin, soman) (47), C18 SPE (sarin, soman) l48 49 , ethyl acetate (VX) (50), usually after precipitation of proteins, and analysis by GC/MS or gas chromatography/nitrogen-phosphorus detection (GC/NPD). Sarin bound to cholinesterase and displaced with fluoride ion was extracted by C18 SPE (see Part B) (51). 

Reactant and exit gas concentrations were measured by gas chromatography. Nitrogen was used as diluent for the butene-l feed. Measurements of the pore size... 

J. Gascon, G. Durand, D. Barcelo, Pilot Survey for Atrazine and Total Chlorotriazines in Estnarine Waters Using Magnetic Particle Based Immnnoassay and Gas Chromatography Nitrogen/Phosphorns Detection , Environ. Sci. Technol, 29,1551-1556 (1995). 

Paik, M.-J. Lee, K.O. Shin, H.-S. Determination of very-long-chain fatty acids in serum hy gas chromatography-nitrogen-phosphorous detection following cyanomethyla-tion. J. Chromatogr. B, 1999, 721, 3-11. 

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