ANALYTICAL STUDY OF A SULFIDE ION-SELECTIVE MEMBRANE ELECTRODE IN ALKALINE SOLUTION

Evaluation of a silver sulfide membrane electrode has revealed sensitivity, selectivity, and other response characteristics well suited to the analytical utilization of such electrodes. Sulfide ion concentrations can be determined by direct potentiometry or potentiometric titration in alkaline solutions without interference from other common anions. The response rate of such electrodes suggests that continuous monitoring of some changing systems is feasible. The thermodynamic solubility product of silver sulfide, (1.48 ± 0.01) × 10−51, and the formation constant (at µ = 0.1) of the SnS32− complex ion, (2.062 ± 0.098) 0×105, have been determined by means of the sulfide ion-sensitive membrane electrode at 25°C. © 1968, American Chemical Society. All rights reserved.