Differential pulse voltammetric assay of atorvastatin in tablets using an unmodified glassy carbon electrode

A differential pulse voltammetric (DPV) procedure was evaluated for the determination of atorvastatin (ATOR) in tablet formulations using an unmodified glassy carbon electrode (GCE). The electrochemical behavior of ATOR was examined by cyclic voltammetry in Britton-Robinson buffer, and pH 4 was selected for further measurements because it provided a well-defined irreversible oxidation signal at approximately +1.05 V vs. Ag/AgCl/3 M KCl. The scan-rate study supported a predominantly diffusion-controlled oxidation process. Under optimized DPV conditions, the anodic peak current was linear in the ATOR concentration range from 0.05 to 0.84 μM. The limit of detection was 13 nM, and the repeatability was 6.4 % for twelve consecutive measurements of 0.11 μM ATOR. The method was applied to commercial Torvacard Novum tablets using the standard addition method, with recoveries from 101.2 to 103.5 %. The procedure is intended as a simple low-concentration assay for tablet extracts after appropriate dilution, without electrode modification, preconcentration or complex sample preparation.