An effective method for enhancing metal-ions’ selectivity of ionic liquid-based extraction system: Adding water-soluble complexing agent

Selective extraction–separation of yttrium(III) from heavy lanthanides into 1-octyl-3-methylimidazolium hexafluorophosphate ([C8mim][PF6]) containing Cyanex 923 was achieved by adding a water-soluble complexing agent (EDTA) to aqueous phase. The simple and environmentally benign complexing method was proved to be an effective strategy for enhancing the selectivity of [Cnmim][PF6]/[Tf2N]-based extraction system without increasing the loss of [Cnmim]+.