Influence of foreign electrolyte concentration in square wave polarography

Abstract

In addition to the established effects of the nature of the foreign electrolyte on the current voltage curves in d.c. polarography, a pronounced dependence of the peak currents on the concentration of the foreign electrolyte is determined in square wave polarography. A marked effect is due to the structure of the double layer. This concentration effect is shown by examples for polarographically reversible and irreversible reductions. Results are of particular importance for applications of this method in microchemical and trace analysis work, since they show that a considerable increase in the sensitivity of indication of irreversible reactions is obtained without the indication of reversible reactions being impaired if, contrary to earlier recommendations, solutions of low foreign-electrolyte content are used. The charging current waves occurring at a high resistance of the cell circuit are described.