Liquid-liquid partition chromatography is widely used as a clean-up procedure for organophosphorus pesticides from various matrices. However, gel permeation is now increasingly used for multipesticides determination. This investigation evaluated the gel permeation chromatography(GPC) for clean-up of monocrotophos in an oil matrix. The gel used in this study was Bio-Beads SX-3 and the GPC solvent system cyclohexane:ethyl acetate (1:1 v/v). The analyte was determined in a gas chromatograph fitted with a flame photometric detector in the phosphorus mode. Recovery of monocrotophos was 74.3%-101.6% with a standard deviation of 3.409-13.453. The method is used for monitoring monocrotophos in edible oil.

Keywords: Bio-Beads, clean-up, gel permeation chromatography, monocrotophos, oil matrix, organophosphorus, residue