COMPARATIVE STUDY ON SOLVENT EXTRACTION METHODS FOR THE DETERMINATION OF PESTICIDE RESIDUES IN VEGETABLES

A study was carried out to compare the solvent extraction method for the determination of organophosphorus and pyrethroid pesticides in vegetables. Two organophosphorus and one pyrethroid pesticides were extracted by using ethyl acetate and cleaned up with Florisil and activated charcoal column other solvent acetonitrile (MeCN) containing 1% of acetic acid, followed by cleanup of the extract was carried out with primary secondary amine (PSA) and magnesium sulphate and residues were analysed by gas chromatography equipped with mass detector. In this study several reasons, MeCN was found to be the most suitable solvent for extraction of a wide polarity range of pesticide residues from vegetables. MeCN offers advantages in extraction selectivity and compatibility with more diverse analytical techniques compared to EtAc. Pesticides extracted using this method was determined by gas chromatography equipped with mass detector. Better recovery was obtained when the samples extracted with acetonitrile in comparison to ethyl acetate. Recovery of the pesticides were in the range of 80-102.%.