Electrodes with extremely high hydrogen overvoltages as substrate electrodes for stripping analysis based on bismuth-coated electrodes

Hydrogen evolution bothers stripping analysis significantly. Dioctyl phthalate-based carbon paste electrode exhibits extremely wide cathodic potential window. It is explored as a powerful substrate electrode to solve the problem of hydrogen evolution and further improve reproducibility for stripping analysis using bismuth-coated electrodes for the first time. It was successfully applied to the simultaneous determination of Zn2+, Cd2+, and Pb2+. Linear responses are obtained for Zn2+ in the range of 10-100 mu g L-1 and for Pb2+ and Cd2+ in the range of 5-100 mu g L-1. The detection limits for Zn2+, Cd2+, and Pb2+ are 0.1 mu g L-1, 0.22 mu g L-1 and 0.44 mu g L-1, respectively. The method has been successfully applied to the determination of Zn2+,Cd2+, and Pb2+ in waste water samples. The detection strategy based on the combination of dioctyl phthalate-based carbon paste electrode and bismuth-coated electrodes holds great promise for stripping analysis. (C) 2012 Elsevier B.V. All rights reserved.