ELECTROCHEMICAL OXIDATION OF BENTAZON AT A GLASSY-CARBON ELECTRODE - APPLICATION TO THE DETERMINATION OF A COMMERCIAL HERBICIDE

The electrochemical methods cyclic, differential pulse and square wave voltammetry were applied to develop an electroanalytical procedure fo r the determination of the herbicide bentazon in a commercial product, containing bentazon as the active ingredient, used to treat rice and corn crops. The oxidation mechanism is complex, consisting of an elect rochemical step followed by chemical dimerization reaction of the prod ucts, which causes severe adsorption problems and consequent poisoning of the electrode surface. The effect of adding Triton surfactant is t o enable determinations with good reproducibility to be carried out; t he analytical conditions were studied and optimized. The limit of dete ction obtained was 10(-5) M. (C) 1998 Elsevier Science B.V. All rights reserved.