Selective electrochemical behavior of highly conductive boron-doped diamond electrodes for fluvastatin sodium oxidation

Boron-doped diamond electrodes have received much attention for electrochemical determination due to their attractive electrochemical properties over other electrodes. The electrooxidation of fluvastatin sodium at boron-doped diamond electrode was investigated using cyclic, differential pulse and square wave voltammetry. The possible mechanism of oxidation was discussed with model compounds that have indole oxidation. The dependence of the peak current and potentials on pH, concentration, scan rate, and the nature of the buffer were investigated. The oxidation of fluvastatin was irreversible and exhibited a diffusion-controlled fashion. The slope of the log in-log v linear plot was 0.44 indicating the diffusion control for pH 10.00 Britton-Robinson buffer solution. The linear response was obtained in the ranges of 1 X 10(-6) M-6 X 10(-4) M in pH 10.00 BR buffer solution. The detection limit of the standard solution is estimated to be 1.37 X 10(-7) M for DPV, 1.44 X 10(-7) M for SWV. The repeatability of the methods was found as 0.66 and 0.15 RSD % for peak currents for differential pulse and square wave voltammetry, respectively. The practical analytical value of the method is demonstrated by quantitative determination of fluvastatin in pharmaceutical formulation and human serum, without the need for separation or complex sample preparation, since there was no interference from the excipients and endogenous substances. Selectivity, reproducibility and accuracy of the developed methods were demonstrated by recovery studies. (c) 2007 Elsevier B.V All rights reserved.