Determination of Lansoprazole in Human Serum by Square Wave Adsorptive Stripping Voltammetry

The electrochemical behavior of the proton pump inhibitor drug lansoprazole was investigated by cyclic and square-wave voltammetry on a hanging mercury drop electrode. Lansoprazole showed single cathodic peak in Britton–Robinson buffer solution (0.04 M; pH 9.0) at −1.310 V vs. Ag–AgCl–sat. KCl. Square-wave adsorptive stripping voltammetry shows a good linearity between the height of this peak and the analyte concentration in the range from 1 nM to 50 nM with a limit of detection of 0.25 nM following stirring of 60 s at −0.6 V. The relative standard deviation determined from ten determinations at the 10 nM level was 1.6%. The method was applied for the determination of lansoprazole in spiked serum samples.