Isotope effects of gallium and indium in cation exchange chromatography

The isotope effects of gallium (69/71Ga) and indium (113/115In) have been determined in the system: strong cation exchanger (Dowex 50-X8)/HCl. The sings of gallium and indium effects were opposite, i.e., the heavier isotope of gallium was fractionated into the resin phase, while the heavy isotope of indium was fractionated into the liquid phase. The values of unit separation gains were found to be +3.0 ´ 10-5 for gallium and –2.0 ´ 10-4 for indium. A possible explanation of the effects is proposed.