title: Highly efficient extraction separation of lanthanides using a diglycolamic acid extractant.
abstract: Liquid-liquid extraction of lanthanide ions (Ln(3+)) using N,N-dioctyldiglycolamic acid (DODGAA) was comprehensively investigated, together with fluorescence spectroscopic characterization of the resulting extracted complexes in the organic phase. DODGAA enables the quantitative partitioning of all Ln(3+) ions from moderately acidic solutions, while showing selectivity for heavier lanthanides, and provides remarkably high extraction separation performance for Ln(3+) compared with typical carboxylic acid extractants. Furthermore, the mutual separation abilities of DODGAA for light lanthanides are higher than those of organophosphorus extractants. Slope analysis, loading tests, and electrospray ionization mass spectrometry measurements demonstrated that the transfer of Ln(3+) with DODGAA proceeded through a proton-exchange reaction, forming a 1:3 complex, Ln(DODGAA)3. The stripping of Ln(3+) from the extracting phase was successfully achieved under acidic conditions. Time-resolved laser-induced fluorescence spectroscopy revealed that the extracted Eu(3+) ions were completely dehydrated by complexation with DODGAA.
authors: Division of Chemistry for Nuclear Engineering, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency (JAEA).
authors: Kojiro
authors: K
authors: Shimojo
authors: Noboru
authors: N
authors: Aoyagi
authors: Takumi
authors: T
authors: Saito
authors: Hiroyuki
authors: H
authors: Okamura
authors: Fukiko
authors: F
authors: Kubota
authors: Masahiro
authors: M
authors: Goto
authors: Hirochika
authors: H
authors: Naganawa