Electrolytic detection of alkali salts on filter paper

SINCE the work of Lederer1 and Arden et al.2, the separation of inorganic cations by paper chromatography has been developed rapidly. The alkali salts, however, do not appear to have been studied, because of the difficulties of detection of alkali cations on the filter paper. We have recently discovered a simple electrolytic method of detecting the alkali and alkaline earth cations, and have studied the paper chromatography of the alkali salts.