Determination of clozapine by adsorptive anodic voltammetry using glassy carbon and modified carbon paste electrodes

Abstract

The electrochemical behaviours of a glassy carbon electrode (GCE) and a carbon paste electrode (CPME) modified with sepiolite were compared in the determination of clozapine.

The procedure, under the optimum conditions for both electrodes, gave linear concentration ranges of 0.06–0.33 µg ml^–1 in 0.1 M phosphate buffer (pH 3.2) with a detection limit of 7.1 ng ml^–1 for the GCE and 0.03–0.26 µg ml^–1 in 10^–2M KNO₃(pH 4.2)(a pre-concentration step being carried out with an open circuit at pH 4.2) with a detection limit of 34 ng ml^–1 for the CPME. The direct determination of clozapine in human serum samples is possible when the CPME is used, but a decrease of 15% in the signal is observed.