Elimination voltammetry. Experimental verification and extension of theoretical results

Abstract

The theoretical results of elimination voltammetry with linear scan have been verified experimentally for the case of reversible and irreversible processes and for the potential range expansion. All experiments were performed with a hanging mercury drop electrode. An experimental extension of elimination for cyclic voltammetry reverse scans of reversible and irreversible electrode processes and for forward and reverse scans of quasireversible electrode processes has been made. The equations for elimination of reversible, charging and kinetic currents, I r, I c and I k respectively, were tested for six cases: (A) simultaneous elimination of I k and I c with I r conservation; (B) simultaneous elimination of I c and I r with I k conservation; (C) simultaneous elimination of I r and I k with I c conservation; (D) elimination of I k with I r conservation; (E) simultaneous elimination of I c and a deeper suppression of the irreversible current foot with I r conservation; (F) elimination of I c with I r conservation. Scan rate ratios using the base number 2 were used. It was proved that the case C could be used with advantage for sensitive detection of the reversibility loss of the electrode process and for the distinction and quantitative measurement of the irreversible electrode process in the presence of a reversible one. The cases A, D and E were proved to be successful for the potential range expansion.