Voltammetric Studies of the Use of the Rotated Oxide Electrode as an Indicator Electrode and as a View to the Determination of EDTA and Other Complexanes

Article abstract of DOI:10.1246/bcsj.55.2056

The accessible potential ranges of rotated lead dioxide (PbO2) and manganese dioxide (MnO2) electrodes were investigated in supporting electrolyte solutions of 0.1 mol/1 (mol/dm³) KNO3 at various pH values, by measuring the base currents of these oxide electrodes.The anodic and cathodic ascending potentials of both the oxide electrodes are pH-independent in a neutral solution.In each neutral system of KNO3, KClO4, K2SO4, and KCl, the acessible potential range of the PbO2 electrode was from +1.4 to +0.2 V vs.SCE, while that of the MnO2 electrode was from +1.2 to +0.3 V, and the lower manganese oxide electrode from +0.3 to -0.9 V.Furthermore, the applications of these electrodes to the determination of EDTA and other complexanes were examined.Both the oxide electodes gave a good calibration curve which could establish a linear relationship to the EDTA concentration, passing through the point of origin.The rotated PbO2 and MnO2 electrodes seem to be useful for determining depolarizers such as the EDTA-type complexanes.