Electroanalytical determination of the herbicide picloram in natural waters by square wave voltammetry

This paper describes the use of square wave voltammetry for the electroanalytical determination of picloram in aqueous media. The reaction was found to occur via an irreversible mechanism involving the transference of four electrons, with the reagent adsorbed in the electrode surface. The practical application was carried out with spiked water samples originated from purified water and from three different local creeks, two of which are highly polluted with industrial and domestic effluents. The calculated detection limits ranged from 11 (for pure and unpolluted waters) to 39 ppb for the most contaminated sample. These low values indicate that such methodology can be conveniently applied in trace analysis.