Highly Promising Method for the Decontamination of Europium from Americium Using an Extraction Chromatography Resin Containing a Tripodal Diglycolamide and SO₃Ph-BTP as Eluent

Separation of Am³⁺ from Eu³⁺ was demonstrated by extraction column chromatography using a tripodal diglycolamide ligand (T-DGA). A clean separation was achieved by selective complexation of Am³⁺ in the feed with 2,6-bis(5,6-di(sulfophenyl)-1,2,4-triazin-3-yl)pyridine (SO₃Ph-BTP) with a separation factor of about 2000. The extraction chromatography resin material with particle size in the range of 175-250 μm contained only 7.4% T-DGA ligand (53 μmol/g) and is one of the most efficient materials used for this purpose until date. Parameters such as feed acidity and SO₃Ph-BTP concentration were varied, while keeping the other parameters constant for getting the best optimized condition for the separation of Am³⁺ from Eu³⁺ ions. The optimized feed condition was 0.1 M HNO₃ containing 10 mM SO₃Ph-BTP for the clean separation of Am³⁺ from the Eu³⁺ fraction. In the feed solution containing Eu³⁺ and Am³⁺, the latter was complexed with SO₃Ph-BTP and, therefore, was not retained on the column, whereas the uncomplexed Eu³⁺ could be efficiently held onto the column. Finally, the loaded Eu³⁺ from the column was eluted with 0.1 M HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid), giving a sharp and narrow elution curve. The radiation stability of the resin was excellent up to 1000 KGy gamma dose, and an identical separation efficiency of the resin was noted with the irradiated resin column, as was obtained with the pristine resin.