Studies on Analysis of Organophosphorus, Pyrethroid and Organonitrogen Pesticides in Vegetables and Fruits

Systematic determination of organophosphorus, pyrethroid and organonitrogen pesticides in vegetables and fruits by GC was developed. Pesticides were extracted from samples using acetone, and re-extracted into hexane. Organophosphorus pesticides in the extract were directly determined by FPD-GC. For determination of pyrethroid (ECD-GC) and organonitrogen (NPD-GC) pesticides, the extract was purified by Florisil column chromatography using 30% ethyl acetate-hexane.The detection limits were 0.005-0.02ppm for pesticides. Organophosphorus, pyrethroid and organonitrogen pesticides were spiked at 0.1ppm, 0.2ppm and 0.2ppm, respectively. Except for dimethoate, ethiofencarb and lenacil, recoveries of pesticides were over 60%.