THIN-LAYER CHROMATOGRAPHIC DETECTION OF ORGANOPHOSPHORUS INSECTICIDESCONTAINING A NITROPHENYL GROUP

A Griess reaction that has been used to detect organic compounds conta ining an aromatic amino group was used to detect organophosphorus comp ounds containing a nitrophenyl group, such as ethyl parathion, methyl parathion, and fenitrothion. On reduction with stannous chloride in HC I-water (1 + 1), these compounds give respective amino derivatives, wh ich are further diazotized and coupled with 1-naphthylamine to give in tense pink-orange spots. This reagent also gives a bluish to violet sp ot with p-nitrophenol, a metabolite of fenitrothion. The procedure can be used to detect these insecticides in biological materials in foren sic toxicology.