Natural metal sulfides as electrochemical sensors for redox titrations in γ-butyrolactone and propylene carbonate

Abstract

Natural monocrystalline pyrite, chalcopyrite, and galena have been used as indicator electrodes for potentiometric redox titrations in γ-butyrolactone and propylene carbonate. Copper(II) solution was employed as the titrating agent. The results obtained by using these electrodes were compared with those obtained by application of a platinum electrode under the same conditions, and good agreement, reproducibility, and accuracy were obtained. The results deviated by 0.16–0.50% from those obtained by using a platinum electrode. All the electrodes showed a relatively fast response time and can be used without any time limit or without considerable divergence in the potentials. The potential jumps at the titration end-point obtained in the titration of some compounds by using a pyrite electrode are higher than those obtained by application of platinum as the indicator electrode.