Extraction of alkali metals by cryptand [2.2.2]

Extraction of alkali metals from aqueous solutions of complex salt composition by cryptand [2.2.2] (4,7,13,16,21,24-hexahydroxy-1,10-diazabicyclo-(8.8.8)-hexacosan) is studied. The flame-photometric method has been applied for analysis of aqueous phases. Organic solvent is shown to essentially affect coefficients of metal separation and distribution. The highest coefficients of separation are attained when using chloroform and nitrobenzene (β > 102-103 for 0.1 M extractant solution). Li/Na, Li/K, Na/Rb, Na/Cs, K/Cs pairs can be separated, for Li, Rb and Cs do not practically transfer to the organic phase under the studied conditions. LiCl, CH3COOLi have been used as salting out agents. Optimum conditions of extraction and concentrating are stated to be achieved at high concentration of salting out agents. Extraction of alkali metals should be preferably conducted with perchlorate, nitrate or chloride solutions