Identification of radiolytic products of [C4mim][NTf2] and their effects on the Sr2+ extraction.

The trace water-soluble radiolytic products of neat 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C(4)mim][NTf(2)]) were identified by analysing water-washed samples of γ-ray irradiated ionic liquids. CF(3)SO(2)OH, CF(3)SOOH, CF(3)SO(2)NH(2), HF and H(2)SO(3) were confirmed as main radiolytic products of [C(4)mim][NTf(2)], and the total radiation chemical yields of the water-soluble radiolytic products (0.35 μmol J(-1)) and that of hydrogen ions (0.46 ± 0.02 μmol J(-1)) were determined by using ion chromatography and neutralization titration, respectively. It was found that the water-soluble radiolytic products of [C(4)mim][NTf(2)] greatly reduced the extraction efficiency of Sr(2+) from water to irradiated [C(4)mim][NTf(2)], while the water-insoluble radiolytic products of [C(4)mim][NTf(2)] had a slight influence on the Sr(2+) extraction.