Study of the copper-zinc interference in potentiometric stripping analysis

Abstract

The severe mutual interference between copper and zinc which occurs when working with a mercury film electrode in potentiometric stripping analysis has been studied. The results obtained are consistent with the formation of 1 : 1, 1 : 2 or 1 : 3 Cu-Zn compounds, depending on the experimental conditions. The gallium additions method, used for the elimination of this interference, does not give good results for solutions with a copper content that is very much greater than that of zinc, but it is effective for copper to zinc ratios of the order of unity or less, a situation that often occurs with environmental samples.