Extraction of Lanthanides(III) from Aqueous Nitric Acid Solutions with Tetra(n-octyl)diglycolamide into Methyltrioctylammonium Bis(trifluoromethanesulfonul)imide Ionic Liquid and Its Mixtures with Molecular Organic Diluents

The extraction of lanthanides(III) from aqueous nitric acid solutions with tetra(n-octyl)diglycolamide into methyltrioctylammonium bis(trifluoromethanesulfonul)imide ([N1888][Tf2N]) ionic liquid and its mixtures with molecular organic diluents is investigated in this study. This study also investigates the effect of HNO3 concentration in the aqueous phase on the extraction of Ln(III) ions. Subsequently, the stoichiometry of the extracted complexes is determined, and the mechanism of Ln(III) extraction in a system with [N1888][Tf2N] is discussed. It is shown that the intragroup selectivity of the extraction of Ln(III) ions is significantly higher when using [N1888][Tf2N] than when using the imidazolium-based ionic liquid [C4mim][Tf2N].