SELECTIVE ELECTRODES FOR SILVER AND ANIONS BASED ON POLYMERIC MEMBRANES CONTAINING COMPLEXES OF TRIISOBUTYLPHOSPHINE SULFIDE WITH SILVER

Polymer membrane ion-selective electrodes have been prepared by using a water-insoluble complex of silver with tri-isobutylphosphine sulfide (TIBPS) as the ion carrier. These electrodes respond to silver as well as to iodide, thiocyanate, and bromide in a near-Nernstian fashion. In addition, they present good detection limits for the above-mentioned ions. It is postulated that the mechanism of response of these electrodes is very similar to the one of the pressed-pellet electrodes. Since the latter exhibit interference by sulfhydryl-containing proteins, the effect caused by ovalbumin on the TIPBS-based electrodes has been investigated. Reduction of this interference is achieved by using polymeric matrices that contain free hydroxyl or carboxyl groups.