SEPARATION OF Rb AND Cs BY EXTRACTION ION EXCHANGE CHROMATOGRAPHY

The separation of 86 Rb and 134 Cs on cation exchange resin columns of sodium tetraphenyl-borate (NaTPB) solutions were studied with eluents of selected water-immiscible organic solvents or their mixtures. Methyl isobutyl ketone (MIBK), nitroethane, and amyl acetate were tested. A satisfactory separation of Rb and Cs can be achieved on a cation exchange resin column in calcium form by use of 0.2 M NaTPB solution in MIBK as the eluent. A complete separation of Rb and Cs was made on sodium-form resin column by eluting with 0.05 M NaTPB in mixture of MIBK and nitroethane in the ratio of 1:1 to 1:3 (V/V), followed by pure nitroethane.