ELECTROCHEMICAL STUDY OF THE CHLORSULPHUR ON - APPLICATION TO THE ANALYSIS OF COMMERCIAL SAMPLES

The electrochemical characteristics of the herbicide chlorsulphuron 5- triazin-2-yl)amino]carbonyl]benzenesulphonamide] have been studied bet ween pH 1 and 6, using several polarographic techniques, namely DC, TA ST and DP polarographies, as well cyclical and differential pulse volt ammetries with HDME. The reduction of this molecule evolves in two pro cesses at a very close potential. Both processes are irreversible and are ruled simultaneously by diffusion and adsorption phenomena; in bot h processes two protons of the medium intervene and two electrons are transferred. The resultant products of the electrochemical reduction o f the herbicide are: 2-chlorbenzene-sulphonamide and 2-amino-4-methoxy -6-methyl-1,3,5-triazine. The quantitative determination of chlorsulph uron has been carried out applying DPP in acetate buffer pH = 3 and re aching a detection limit of 8.5 . 10(-8) M. Finally, we have proceeded to the quantification of chlorosulphuron in commercial samples obtain ing results which do not differ more than 2,5% from the certified valu es.