Room temperature ionic liquid diluent for the extraction of Eu(III) using TRUEX extractants

Extraction of europium(III) from nitric acid medium by a solution of tri-n-butylphosphate (TBP) and n-octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in the room temperature ionic liquid, 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (amimNTf(2) where a = butyl or hexyl or octyl), was studied. The distribution ratio of Eu(152+154)(III) in TBP-CMPO/bmimNTf(2) was measured as a function of various parameters such as the concentrations of nitric acid, CMPO and NaNO3. Remarkably large distribution ratios were observed for the extraction of europium(III) when bmimNTf(2) acted as diluent. The stoichiometry of metal-solvate in organic phase was determined by the slope analysis of extraction data.