Spectrophotometric determination of isoproturon or metoxuron using p-dimethylaminobenzaldehyde

Abstract

A spectrophotometric method for the determination of isoproturon (IPN) or metoxuron (MTN) based on their reaction with p-dimethylaminobenzaldehyde under acidic conditions is described. The absorption maxima of the coloured compounds formed are observed at 438 and 444 nm and the molar absorptivities are 3.09 × 10⁴ and 3.85 × 10⁴ l mol^–1 cm^–1 for IPN and MTN, respectively. The relative error is <1%. The method is simple and convenient and was applied successfully to the determination of IPN or MTN in technical-grade samples and formulations.