An assessment of some methods of analysis for dimethoate residues in fruit and vegetables

Abstract

Three methods for determining residues of dimethoate, OO-dimethyl S-(N-methylcarbamoylmethyl) phosphorodithioate, in fruits and vegetables have been investigated for the purpose of recommending a standard method that can be applied to a variety of temperature fruits grown in the United Kingdom. Laws and Webley's general method for determining organophosphorus insecticide residues was satisfactory for residues of dimethoate in sprouts, lettuces and apples, but not in peas. Chilwell and Beecham's procedure was also satisfactory at the 1 or 2 p.p.m. level of added dimethoate in cabbages, lettuces, apples and peas. Giang and Schechter's method, however, gave variable results.