Amperometric titration of palladium, silver and copper with benzimidazol-2-ylmethanethiol, and its application to non-ferrous materials

A method is described for the determination of mg amounts of palladium, silver and copper by amperometric titration with benzimidazol-2-ylmethanethiol in acetate buifer medium (pH 4-5) at an applied potential of -0.2 V vs. the saturated calomel electrode. Direct titrations are possible in the presence of a number of foreign ions. Copper and palladium interfere mutually and in the determination of silver. Mercury(I), mercury(II) and platinum(IV) also interfere. Silver does not interfere in the determination of copper and palladium if it is first precipitated as chloride. The method has been successfully applied to the analysis of non-ferrous materials.