A RAPID MULTIRESIDUE SCREEN FOR ORGANOPHOSPHORUS, ORGANOCHLORINE, ANDN-METHYL CARBAMATE INSECTICIDES IN PLANT AND ANIMAL-TISSUES

A multiresidue screen for the quantitative determination of 43 organop hosphorus, 17 organochlorine, and 11 N-methyl carbamate insecticides i n 10 g of plant or animal tissues is described. The insecticides are e xtracted with 5% ethanol in ethyl acetate (v/v). Samples with high lip id content are cleaned up by automated gel permeation chromatography w ith a 30% ethyl acetate in hexane (v/v) eluant and in-line silica gel minicolumns. Highly pigmented samples are cleaned up with class-specif ic solid-phase extraction columns. The concentrated extracts are analy zed by selective detection with gas chromatography or liquid chromatog raphy. Recovery of 71 insecticides ranged from 77 to 113%. Analysis of fortified bovine liver (n = 5) resulted in an average recovery of 96 +/- 4% at the 0.5 to 0.05 mu g/g level. Analysis of fortified alfalfa hay (n = 5) resulted in a mean recovery of 94 +/- 4% at the 0.06 to 0. 5 mu g/g level, and analysis of fortified fresh tomatoes (n = 5) resul ted in an average recovery of 97 +/- 3% at the 0.06 to 0.5 mu g/g leve l. Method detection limits ranged from 0.02 to 0.5 mu g/g for the comp ounds studied with a nominal 10 g sample.