[Determination of methyl parathion (0.0-dimethyl-(p-nitrophenyl)-thiophosphoric acid ester) and metabolites in animal material and in feed].

A new thin-layer chromatography method was developed to detect parathion-methyl (0.0-dimethyl-0-p-nitrophenyl phosphorothioate) and its metabolite methyl-paraoxon and the degradation produce p-nitrophenol in samples of animal and plant origin. Coupling with Bratton-Marshall reagent, as used in colorimetry, was employed to detect the compounds on the chromatography plate. Pretreatment of the samples was simplified by preparing a crude extract and separating unwanted substances from the pesticide compounds by thin-layer chromatography.