DETERMINATION OF HYDROLYTIC METABOLITES OF ORGANOPHOSPHORUS INSECTICIDES IN COW URINE USING AN IMPROVED THERMIONIC DETECTOR

A gas Chromatographic method is described for determination of dimethyl or diethyl phosphate, thiophosphate, and dithiophosphate as hydrolysis products of organophosphorus insecticides in cow urine. The method involves ether extraction of acidified urine followed by methylation of the extracted acids. The methyl esters are chromato-graphed using the alkali-thermionic detector. The thermionic detector was modified to improve its stability during extended use. The method is sensitive to about 0.2 p.p.m. of the metabolites in urine. © 1968, American Chemical Society. All rights reserved.