Studies on Inorganic Chromatography. V. Fundamental Studies on Paper Electrochromatography. (2)

Relationship between the pH of the electrolyte solution and the degree of mobility was examined with inorganic ions. Electrolyte used were sodium nitrate, potassium thiocyanate, and tartaric acid series, and the ions detected were Ba++, Pb++, Cu++, Zn++, Ni++, Fe+++, Br-, CNS-, AsO4---, CrO4--, Fe(CN)6---, NO2-, and BO3---. Except in the case of extremely acid or alkaline range, the effect of pH was found to be rather small in inorganic ions in general, both in cations and anions. However, in the case of amphoteric metals, such as zinc, they behave similar to amino acids. Use of complex salt-forming electrolyte in the case of metallic ions, the effect of pH was found to be extremely great. In the case of tartaric acid electrolyte, metals were found to move as a cation in the acid range of lower pH while they behaved as anions in a higher pH range, and there is a certain pH (isoelectric point) at which each metal does not move at all. From these facts, it was found that the complex salt-forming electrolyte was suitable for the separation of metals