A Comparison of Ultratrace and Glassy Carbon Working Electrodes for the Amperometric Detection of Benzo[a]pyrene and Its Hydroxylated Metabolites after HPLC Separation

Abstract

The advantages of microelectrodes and their ability to perform electrochemical measurements in resistive media offer the possibility of an extended use of amperometric detection following HPLC separation, including use of gradient techniques. In this study, the suitability of two selected electrodes was examined for the amperometric detection of benzo[a]pyrene (BaP) and seven of its hydroxylated metabolites in combination with HPLC. It is shown that, in comparison with a conventional glassy carbon macroelectrode the use of an epoxy-impregnated porous graphite electrode (ultratrace electrode) led to a significant reduction in the equilibration time. By incorporation of the ultratrace electrode into the amperometric detector, less dependence of the response from the electrolyte concentration and improved hydrodynamic voltammograms were obtained. Additionally the simultaneous amperometric detection of BaP and its hydroxylated metabolites could be performed after HPLC separation with gradient elution. The use of this ultratrace electrode for amperometric detection coupled with HPLC is described for the first time in this article.