Interference films on the sensor membranes of solid-state copper(II) ion-selective electrodes

Abstract

Copper(II) ion-selective electrodes based on copper(II) sulphide-silver sulphide sensor membranes, which showed anomalous responses with copper(II) nitrate in the presence of chloride, have been examined by Auger spectrometry. In some electrodes exposed to solutions of potassium chloride the chloride is found to have penetrated the bulk of the membrane matrix, whilst in others only a surface contamination is observed. The anomalous electrode response is exhibited when exposure to chloride is in the presence of copper nitrate. The Auger signal alters during the duration of the spectrum as a consequence of electron bombardment. The effects of argon-ion and electron bombardment are compared.