Polycrystalline ion-selective electrode based on Ag2[HgI4]-Ag2S

Abstract

The preparation and analytical behaviour of polycrystalline solid-state ionselective electrodes based on Ag₂[HgI₄] and Ag₂[HgI₄]-Ag₂S membranes was studied. The membranes consist of solid-state pellets made by compressing prepared precipitates. The performance characteristics of the electrodes are described in terms of potential-activity graphs, stabilities, precision, response times, effect of pH and redox potential. The electrode responses towards Ag⁺, Hg⁺, Hg²⁺, I^– and CN^– ions are evaluated. It was found that the Ag₂[HgI₄]-Ag₂S type is superior to the Ag₂[HgI₄] type with respect to mechanical properties and lifetime and is more suitable for practical application.