The determination of residues of dichlorvos and malathion in wheat grain by gas-liquid chromatography

Abstract

A procedure is described for the determination of malathion and dichlorvos in grain. After extraction with methanol, and clean-up on a charcoal column, if required, the pesticide residues are determined by gas-liquid chromatography on Apiezon L and butane-1,4-diol succinate columns with a phosphorus-sensitive detector.

Between the concentrations of 0·25 and 10 p.p.m. both pesticides were recovered from spiked samples with between 87 and 99 per cent. efficiency.