The preparation and analytical evaluation of a new heterogeneous membrane electrode for cadmium(ii)

The preparation of a new cadmium-selective heterogeneous membrane electrode obtained by hot-pressing a mixture of cadmium and silver sulfides with polythene in a moulding press is described. Nernstian response to cadmium ion was achieved only when the mixture of salts was purified by heat treatment at 600° in an atmosphere of hydrogen sulfide for several hours. This behaviour is discussed in terms of the purity of the salts. Interferences and analytical applications in aqueous and nonaqueous solvents are described.