Performance Evaluation of the Four-Electrode Type Measurement System for Ion-Transfer Voltammetry

Abstract

A four-electrode electrolytic cell for ion-transfer voltammetry was designed, in which a stationary oil/water interface can be renewed by pouring an aqueous solution from a reservoir. A new four-electrode potentiostat was also developed in order to achieve ideal iR compensation with a positive-feedback circuit. Performance evaluation of the four-electrode system was made through cyclic voltammetric, chronopotentiometric, and normal-pulse voltammetric measurements for the transfer of tetramethylammonium ion at the nitrobenzene/water interface. The developed potentiostat was found to show a proper response, even when nearly 100% (at least 95%) iR compensation was achieved. A low-pass filter mounted in the potentiostat was successfully employed to reduce noise in current signal.