As a continuation of our work with alloy electrodes [1, 2], silver alloy electrodes containing different amount of bismuth, ranging from 2 to 15 %, have been studied for use as working electrodes in anodic stripping voltammetry.
The electrochemical properties, like the working potential window and potential of hydrogen evolution reaction (HER), are reported. The electrodes have been tested in different solutions. In result, optimal conditions have been found for detection of zinc, cadmium and lead in a sub ppb concentration range in real samples by using differential pulse anodic stripping voltammetry.
Real samples of river and seawater have been examined and concentrations in the ppt range have been detected. With a pre-deposition time of 600 s, the detection limit has been found to be down to 100 ppt for zinc, cadmium and lead, with a standard deviation within 5%.
The use of this non-toxic electrode together featuring outstanding detectability makes the reported system suitable for implementation in continuous monitoring systems for online use.
Key Words: Anodic stripping voltammetry, Silver-bismuth electrode, Hydrogen evolution reaction, Heavy metals, Alloy.
1. O. Mikkelsen and K. H.Schroder, Analyst (2000) 125, 2163-2165.
2. O. Mikkelsen, S. M. Skogvold, K. H. Schroder, M. I. Gjerde, and T. A. Aarhaug, Anal. Bioanal. Chem., (2003) in press.