Simple, rapid, and sensitive electrochemical determination of antithyroid drug methimazole using a boron-doped diamond electrode

This paper aims a rapid, cheap, simple and modification-free electroanalytical methodology using a boron-doped diamond electrode pretreated anodically for the determination of antithyroid drug methimazole in pharmaceutical samples. The drug was irreversibly oxidized which was a diffusion-controlled process. Using square wave voltammetry, a linear response was obtained for methimazole determination in Britton–Robinson buffer (pH 5.0) at + 0.89 V (vs. Ag/AgCl). Linearity was found between the oxidation peak currents and the concentration of methimazole from 0.5 to 25.0 µg mL−1 (4.38 × 10−6–2.19 × 10−4 M) with a detection limit of 0.085 µg mL−1 (7.45 × 10−7 M). The proposed method was applied for the determination of methimazole in commercial tablet samples.