Voltammetric Determination of Labetalol in Pharmaceuticals and Spiked Human Urine

The electrochemical oxidation of labetalol was investigated by cyclic, linear sweep and differential pulse voltammetry at carbon paste electrode in Britton—Robinson buffers over the pH range 2.0—10.0. For analytical purposes, a well-defined adsorption-controlled anodic peak was obtained in Britton—Robinson buffer at pH 2.0. By anodic adsorptive linear sweep and differential pulse voltammetry, linear calibration plots were obtained in the ranges of 2.5 × 10−6—1.0 × 10−5 mol dm−3 and 2.5×10−8—1.0 × 10−5 mol dm−3 for both techniques, respectively. Detection limits were found 1.0 × 10−6 mol dm−3 for LSV and 1.0 × 10−8 mol dm−3 for DPV. Based on this study, two simple, rapid, selective, and sensitive voltammetric methods were developed for the determination of labetalol in tablet dosage form. The preconcentration/medium exchange/voltammetry approach was applied for the drug determination in spiked human urine.