D.G. Racz, I.F. Chaple, S. Jansone-Popova
University of Tennessee-Knoxville,
United States
Keywords: Lanthanide separation, diglycolamide resin, solid-liquid extraction, neutral aqueous complexants, neutral two-ligand strategy
Summary:
This work investigates an innovative solid-liquid separation approach that enhances adjacent lanthanide (Ln) separations by combining diglycolamide (DGA) resins with neutral aqueous complexants. By employing lipophilic DGA ligands in the stationary phase with hydrophilic ligands such as DOODA and BLPhen in the mobile phase, the system exploits opposing selectivity trends to achieve improved separation, particularly among the heavier Lns. Comparative experiments using commercially available TODGA and a novel SDGA resin demonstrate that the neutral two-ligand separation strategy can effectively shorten separation times and increase selectivity. The study extends the ligand “tug-of-war” concept from liquid-liquid extraction to a solid-liquid extraction, offering an operationally robust and efficient pathway for critical lanthanide separations.