Direct stripping voltammetric method for the determination of small concentrations of one component in binary alloys

An attempt was made to determine small concentrations (up to 5 wt.%) of Zn in cast Zn-Cd and Zn-Pb binary alloy samples by using direct stripping voltammetry (DSV). It was shown that DSV of such alloys is sensitive to the content of the less noble metal, in that DSV peaks can be detected in contents as low as 0.8 wt.%. For both investigated alloy samples, well-defined linear dependencies between the charge under the peak of Zn dissolution and the percentage of Zn in the alloy were obtained which makes the method suitable for comparative analysis. In both systems this dependence is characterised with an intercept on the abscissa, which should be due to the formation of a solid solution between the components in the solid phase. A reproducible manner of surface preparation is required for satisfactory precision to be achieved. Under many conditions the relative standard deviation (RSD) was ≤ 9%. Qualities of the method are: simple and cheap instrumentation, an easy and fast procedure, and applicability for routine analysis.