Lithium Isotope Effects in Cation Exchange Chromatography of Lithium Lactate in Water-Dimethyl Sulfoxide and Water-Acetone Mixed Solvent Media

Abstract

Lithium isotope separation by ion exchange displacement chromatography of lithium lactate in water-dimethyl sulfoxide (DMSO) and water-acetone mixed solvent media at 25 °c was explored. In both the water-DMSO and water-acetone system, the single stage isotope separation factor (S) was a convex function of the mixing ratio of the solvents in the external solution phase; S had its maximum value of 1.00254 at water: DMSO = 25:75 v/v and 1.00182 at water: acetone = 75:25 v/v. Strong correlations of S with solvent partitions between the solution and the exchanger phases were found in both systems, which was qualitatively explainable by considering the lithium isotope distributions between the two phases based on the fundamental lithium isotope effects and the relative affinities of water, DMSO and acetone towards the lithium ion. © 1993, Walter de Gruyter. All rights reserved.