THIN-LAYER CHROMATOGRAPHIC DETECTION OF CARBARYL USING PHENYLHYDRAZINE HYDROCHLORIDE

A new chromogenic spray reagent for the detection of the commonly misu sed carbamate insecticide carbaryl, is described. Carbaryl, on alkalin e hydrolysis, yields 1-naphthol, which in turn reacts with phenylhydra zine hydrochloride to give a red complex. This reagent is selective fo r carbaryl. There is no interference from other carbamate insecticides or from organophosphorus, organochlorine and pyrethroid insecticides or from constituents of visceral extracts (amino acids, peptides, prot eins, etc.). The limit of detection of the reagent is ca. 0.1 mu g per spot (i.e. ca. 350 ng/cm(2)) observed after development.