Fate of malathion and chlorpyrifos methyl in rough rice and milling fractions before and after parboiling and cooking.

Long-grain rough rice treated with malathion (14 ppm) or chlorpyrifos methyl (Reldan) (6 ppm or 12 ppm) was sampled after 1,6, and 12 wk. Samples from each treatment were processed raw or were parboiled with fresh steeping water, once-used, and twice-used steeping water. Three replicates of rough rice and of each milling fraction were preserved, and three of milled rice were cooked.

Gas chromatographic determination of CCRL583 perfluorinated alcohol fumigant residues.

A gas chromatographic method is described for the determination of CCRL583 (1,1,1,3,3,4,4,4-octafluoro-2-(trifluoromethyl)-2-butanol). The sample is extracted with acetonitrile and cleaned up by liquid-liquid extraction, first with a basic aqueous solution and finally with an acid aqueous solution. The final organic layer is injected into a gas chromatograph equipped with a column packed with terephthalic acid-terminated Carbowax 20M.

Rapid cleanup procedure for gas-liquid chromatographic determination of chlorpyrifos-methyl residues in cat food.

A simple and rapid gas-liquid chromatographic (GLC) method was developed for the determination of residues of chlorpyrifos-methyl in dry cat food. Cat food fortified with chlorpyrifos-methyl was extracted with acetone and cleaned up on a modified acetonitrile-on-Florisil partitioning column. The chlorpyrifos-methyl was determined by GLC with a flame photometric detector.

Gas-liquid chromatographic determination of m-phenoxybenzyl cis, trans-(+/-)-3-(2,2-dichlorovinyl)-2-2-dimethylcyclopropanecarboxylate in aqueous formulations.

A simple and rapid gas-liquid chromatographic (GLC) method was developed for the analysis of aqueous solutions of FMC 33297 (mphenoxybenzyl cis,trans-(+/-)-3-(2,2-dichlorovinyl) - 2,2 - dimethylcyclopropanecarboxylate). The compound is extracted from aqueous solution with benzene and cleaned up by liquid chromatography. The sample extracts are analyzed by GLC with a flame ionization detector and quantitated by comparing integrator counts of extracts with those of standards.

Determination of pirimiphos methyl in formulations by high performance liquid chromatography.

A simple and rapid method for the determination of pirimiphos methyl (O-[2-(diethylamino)-6-methyl-4-pyrimidinyl] O,O-dimethyl phosphorothioate) in formulations by high performance liquid chromatography is described. The sample is dissolved in methanol, and biphenyl is added as an internal standard. Then the sample is chromatographed by reverse phase chromatography on a Zipax octadecylsilane column.