Spectrophotometric determination of propoxur residues on vegetable matter

Abstract

Propoxur, also known as undeen or arprocarb, contains the active ingredient 2-isopropoxyphenyl-N-methylcarbamate. Alkaline hydrolysis yields 2-isopropoxyphenol, which couples directly with 2,6-dibromo-p-benzoquinone-chloroimide, in a weakly alkaline medium, to give a blue indophenol derivative, the extinction of which is measured against a blank at 595 nm. The amount of propoxur can be read from a calibration graph. By this method, down to 0·1 mg kg^–1 of plant material can be detected.