Speciation of Trace Levels of Chromium with Bismuth Modified Pyrolyzed Photoresist Carbon Electrodes

Pyrolyzed photoresist carbon electrodes modified with bismuth (Bi‐PPCEs) were prepared and used for the determination of trace levels of chromium. In order to lower the detection limit, the choice of the supporting electrolyte concentration and electroanalytical parameters were optimized. The adsorptive cathodic stripping voltammetric determination of Cr(VI) at Bi‐PPCE was selective even in the presence in Cr(III). A detection limit of 0.1 µg L−1 was obtained after 60 s preconcentration. After oxidation with UV light and oxygen, all chromium species were oxidized to Cr(VI) and the total inorganic Cr determination is possible. Finally, Bi‐PPCE was applied to trace Cr(VI) analysis in real samples such as waste water and tap water.