Long-term Integration of Polarographic Currents and Its Analytical Application

Abstract

Abstract The integral readout technique was applied to the accurate determination of average polarographic currents. The long-term integration of polarographic currents provides a useful method of compensating residual currents and thus of increasing the sensitivity and accuracy of the d. c. polarographic analysis. The analytical utility of the proposed method was tested with cadmium, lead, and zinc ions in chloride solutions; these ions were found to be determined with reasonable accuracy even at concentrations as low as 10−6 m. Depolarizers at concentrations of the order of 10−4 m can be determined accurately in air-saturated solutions. The present method has the considerable merit that its sensitivity is not affected by the degree of reversibility of the electrode reaction. The integral technique was also applied successfully to the compensation of residual currents by the twin-cell system, in which a pair of dropping mercury electrodes is not necessarily synchronized.