A rapid, multiresidue procedure utilizing the minimal cleanup necessary for gas-liquid chromatographic (GLC) analysis is presented. The samples are extracted with acetone and partitioned with methylene chloride-petroleum ether to remove water. The organophosphorus and organonitrogen compounds are then quantitated by GLC, using a KCI thermionic detector. A Florisil cleanup of the extract is performed prior to the determination of organochlorine compounds by a GLC electron capture detector. Carbon-hydrogen compounds such as biphenyl and o-phenylphenol undergo the Florisil cleanup and may also be quantitated by GLC. Quantitative recoveries for 15 organophosphorus, 9 organochlorine, 5 organonitrogen, and 2 hydrocarbon pesticides show the range in polarities of pesticides recovered, from Monitor to biphenyl. The method is simple and fast with a great potential for the analysis of many more compounds.

The multiresidue procedure of Luke et al., which uses extraction with acetone and partition with petroleum ether and methylene chloride, was simplified and shortened by eliminating the Florisil cleanup. Double concentration with petroleum ether in the Kuderna-Danish evaporator following the initial concentration removed the last traces of methylene chloride. The extract was then injected into a gas chromatograph, using a Hall electrolytic conductivity detector for organohalogen, organonitrogen, and organosulfur pesticides or a flame photometric detector for organophosphorus pesticides. Recoveries of 79 pesticides are presented.

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Gas chromatographic mass spectrometric techniques using methane chemical ionization have been employed to characterize the chemical composition of Toxaphene reference material, as well as the metabolized residue in milk fat resulting from controlled administration to cows. The results indicated that selection of particular ions can be of great value in determining whether or not an observed residue by electron capture should be attributed to a metabolized residue of Toxaphene. Analysis of six commercial milk samples by electron capture gas chromatography and gas chromatography mass spectrometry/chemical ionization/selected ion monitoring has provided semi-quantitative data for comparison of the determinative step.

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