Extraction behavior and separation of lanthanides with a diglycol amic acid derivative and a nitrogen-donor ligand.

The extraction and separation of lanthanides have been investigated using CHON-type extractants, which are composed of only C, H, O, and N atoms. N,N-Dioctyldiglycol amic acid (DODGAA) showed high extraction and separation performances for heavier lanthanides compared with typical CHON-type extractants. On the other hand, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) provided an unprecedentedly high selectivity for lighter lanthanides. Furthermore, it was found that the combination of DODGAA and TPEN under suitable conditions enabled the mutual separation of light, middle, and heavy lanthanides.