1956 年 76 巻 6 号 p. 747-748
Separation of caffeine, theobromine, theophylline, 3-methylxanthine, and xanthine by paper ionophoresis was examined. By migration with the Sørensen buffer of pH 2.3-11.1, caffeine and theobromine migrate towards the cathodic side at any pH, while the charge of theophylline, 3-methylxanthine, and xanthine changes at around pH 8, the compounds migrating towards the cathode at below pH 8, and towards the anodic side at above that pH. The best separation was effected at pH 8-9 and migration in 0.5% borax solution was found to completely separate the foregoing xanthine derivatives. Paper ionophoresis of the aqueous extract of tea leaves and of cacao beans with 0.5% borax solution was found to collect the spot of caffeine and theobromine, respectively, on the cathodic side, while other components in the aqueous extract migrated towards the anodic side.