Voltammetric determination of phenylglyoxylic acid in urine using graphite composite electrode

A composite electrode prepared from graphite powder and epoxy resin was applied as a working electrode for the determination of phenlglyoxylic acid (one of the metabolites of styrene) in human urine. Cathodic differential pulse stripping voltammetry was used and optimum conditions have been found giving the limit of determination about 5 mg L-1. All results were compared with those obtained using hanging mercury drop electrode. For the confirmation of suggested mechanism of the electrochemical reaction the elimination voltammetry with linear scan Was used.