Multi-residue determination of organochlorine, organophosphorus and synthetic pyrethroid pesticides in grain by gas-liquid and high-performance liquid chromatography

Abstract

A multi-residue method for the determination of organochlorine, organophosphorus and synthetic pyrethroid pesticides and carbaryl in grain is presented. After extraction with acetone-methanol, the pesticides are separated from co-extractives by a partition process with dichloromethane and chromatography on an acidic aluminium oxide column. Quantitative determinations are made by packed column gas-liquid chromatography using an electron-capture detector for the organochlorine pesticides and a flame-photometric detector for the organophosphorus pesticides. High-performance liquid chromatography using an ultraviolet spectrophotometric detector is used for the determination of synthetic pyrethroids and carbaryl. Capillary column gas-liquid chromatography is used for confirmation of identity of suspected residues of organochlorine, organophosphorus and synthetic pyrethroid pesticides.