Column Separation of Rare-earth Ions by XAD-7 Resin Loaded with Bis(2-ethylhexul) Hydrogenphosphate

The selective adsorbent for rare-earth ions was prepared by loading bis(2-ethylhexyl) hydrogenphosphate (B 2 EHP) on XAD-7 resin, and the distribution ratios of individual rareearth ions between the resin and the aqueous solution have been determined. The distribution ratio increased with the increase of atomic number of the elements (Fig.2), and the mean separation factor for every neighboring pairs was found to be 2.4. In the chromatographic separation on the B 2 EHP resin column by stepweise elution with O.15 M-3.0 M HCI solution, all of the lanthanoid ions(except prometium) was eluted in the order of their atomic number (Fig.3) and were separated completly.