Voltammetric Determination of Ethionamide in Pharmaceutical Formulations and Human Urine using a Boron-Doped Diamond Electrode

This work reports a simple and low cost voltammetric approach comprising a boron-doped diamond electrode (BDDE) to determine the antibiotic ethionamide (ETO). Cyclic voltammetry studies revealed that ETO exhibits an irreversible reduction peak at -0.95 V and an irreversible oxidation peak at +1.4 V onto BDDE (vs. saturated Ag/AgCl reference electrode) in Britton-Robinson buffer solution (pH 5.0, 0.1 mol L-1). Different voltammetric scan rates (from 10 to 150 mV s-1) suggested that the reduction of ETO on the BDDE surface is a diffusion-controlled process. Square wave voltammetry (SWV) optimize...