Determination of Pesticide Ethion by Linear Sweep Stripping Voltammetry

The presence of the pesticide ethion was determined using an electroanalytical method, i.e., linear sweep stripping voltammetry at a hanging mercury drop electrode in the Britton-Robbinson buffer with pH=8.36, based on its reduction peak observed at -690 mV following its alkaline hydrolysis. The experimental parameters, namely, the preconcentration potential, the preconcentration time, and the scan rate were investigated and -300 mV（vs. Ag/AgCl）, 270 s, and 100 mV/s were selected as the optimal values, respectively. The linear relationship between the peak current and the concentration was found to be in the range of 0.020.16 mg/L, with a detection limit of 0.0087 mg/L. The proposed method was applied to the determination of ethion in spiked vegetable and fruit samples via a preextraction with anhydrous ethanol.