定電位電解分析法の研究(第1～2報)

Abstract

The method of electroanalysis by a controlled cathode potential was first investigated and published in 1907 by H. J. S. Sand, but almost no significant development of this method has been made, on account of the complexity of its manually operated potential control. However, recent developments in the equipment for electroanalysis with automatically controlled potential have attracted attention in this field. Since there has been no systematic investigation of the various electrolytes for electroanalysis using a platinum electrode, the electrodeposition of various metals in solutions of various electrolytes has now been carried out.The electrolytes studies included those acidified with hydrochloric acid, sulfuric acid, nitric acid, and tartaric acid; those made alkaline with ammonia; and also those containing potassium cyanide or EDTA. The data are tabulated. The conditions required for quantitative determination of these metals were determined in order to establish a systematic analysis. The apparatus for electroanalysis, the methods of estimation of potential for electrodeposition, the procedure for quantitative electroanalysis and that for electrolytic separation, are all described in this report.Electrodeposition of metal ions from a solution containing 0.3 N HCl and 0.14 M NH2OH·HCl using a platinum electrode has been investigated.An eletrodeposition potential for each metal on the cathode against a standard calomel electrode has been estimated with the following results: Au + 0.60 V, Hg + 0. 15 V, Cu-0.15 V, Bi-0.15 V, Sb-0.20 V, Sn-0.-0.50 V, Pb-0.55 V, and Cd-0.80 V, (vs. S. C. E. ). Electroanalyses of these metal ions using the above controlled cathode potentials indicated that the electrodepositions of these metals were quantitative and good results were obtained for separatory electroanalysis of Cu-Sn, Cu-Cd, Sn-Cd, and Sb-Cd.