Colorimetric determination of propoxur and its residues in vegetables.

A method has been developed for the detn. of propoxur (o-isopropoxyphenyl N-methylcarbamate) based on the hydrolysis of propoxur with methanolic KOH to its phenol and coupling with diazotized 4,4-diaminodiphenyl sulphone. The orange complex formed has an absorption max. at 500 nm and obeys Beer's law in the range 0.25-5.0 mug/ml. The method can be applied to levels as low as 0.5 p.p.m. propoxur from vegetables.