Electrochemical elimination of the pesticide methylparathion in an aqueous medium

One of the most important transformation reactions of methylparathion, an organophosphorus pesticide, was studied. The redox transformation of methylparathion was carried out using different electrochemical methods in an aqueous medium. The study was based on direct current (DCP) and differential pulse (DPP) polarography, cyclic voltammetry (CV) and coulometry. The results show that the pesticide produces a single step or two steps depending on the pH and the electrode. The average value for the limit of detection (3 s) was (2.05 +/- 0.41) x 10(-8)mol dm(-3) (5.4 +/- 1.1 mug l(-1)) for DPP. The electrochemical behavior of methylparathion and the nature of the electrolysis products was interpreted according to the electrochemical and spectroscopic data. The experimental data were employed to predict the fate of the pesticide in water samples.