Ion-selective electrodes based on silver sulphide

A series of electrodes with membranes of silver sulphide have been prepared. Their standard potentials and their response to sulphide and silver ions are measured and compared with those of a single-crystal silver sulphide electrode. The selectivity parameters against heavy metal ions and halides, as well as cyanide, are discussed. It is concluded that only interferences from cyanide ions and mercury(II) ions are detrimental to the practical use of the electrodes for measuring pAg and pS.