γ-ray induced radiolysis of [C2mim][NTf2] and its effects on Dy3＋ extraction

The water-soluble radiolytic products of 1-ethyl-3-methylimidazolium bis（trifluoromethylsulfonyl） imide ionic liquid （[C2mim][NTf2]） under γ-radiation, such as CF3SOOH, CF3SO2NH2, HF, and H2SO3, were identified by using 1H NMR, 19F NMR, and ion chromatography. The extraction behavior of Dy3＋ using irradiated [Czmim][NTf2] in combination with 2,6-di（5,6-diisobutyl-1,2,4-triazin-3-yl）pyridine （isobutyl-BTP） was studied and the abnormal increase of Dy3＋ partitioning after irradiation is mainly attributed to the precipitation formed between Dy3＋ and radiolytic products of [C2mim][NTf2] （F and SO2 ）. Washing irradiated [C2mim][NTf2] with water provides a simple method for ionic liquid recycling.