MULTIRESIDUE METHOD FOR DETERMINATION OF ORGANOPHOSPHORUS INSECTICIDERESIDUES IN FATTY PROCESSED FOODS BY GEL-PERMEATION CHROMATOGRAPHY

A multiresidue method for quantitative determination of 39 organophosp horus compounds (parent pesticides and their major metabolites) in 7 f atty processed foods is described, Samples are extracted with methylen e chloride and cleaned up by automated gel permeation chromatography w ith a Biobeads SX3 column and a methylene chloride-cyclohexane (15 + 8 5) eluant. Organophosphorus compounds are quantitated by capillary gas -liquid chromatography with flame photometric detection using OV-1701 and DB-5 columns, Average recoveries from samples fortified at 0.025-1 mg/kg ranged from 50.6% for dichlorvos to 185% for malaoxon, Determin ation limits were between 0.005 and 0.040 mu g/mL. Results were confir med by gas chromatography/mass spectrometry with selected-ion monitori ng.