Identification of a biomarker for propetamphos and development of a biological monitoring assay

This paper describes the identification of a human metabolite of propetamph os ((E-O2-isopropylcarbonyl-1-methylvinyl-O-methylethylphosphoramidothioate ), formed by the hydrolytic cleavage of the enol-vinyl-phosphate bond, and the development of an analytical method suitable for biological monitoring of propetamphos exposure. The metabolite has been detected in the urine of exposed workers but not in that of control subjects. The analytical method involves azeotropic distillation of the urine with acetonitrile, followed b y derivatization with pentafluorobenzyl bromide and analysis using gas chro matography with flame photometric detection.