On the suppression of zinc-copper interactions in square wave anodic stripping voltammetry in flowing solution by addition of gallium ions

The problems arising from the formation of copper-zinc intermetallic compounds in square wave anodic stripping voltammetry at wall-jet mercury thin-film electrodes in continuous flow systems have been investigated. These effects are reduced to zero by spiking the analyte solution with gallium ions and ensuring a sufficiently low value of pH, either by using acetate buffer or acidifying the generally-used sodium perchlorate electrolyte. Advantages of this approach are assessed, as are the benefits of stopping solution flow during the determination step of each experiment.