γ-radiation effect on Th4+ extraction behaviour of TODGA/[C2mim][NTf2]: identification and extractability study of radiolytic products

The gamma-radiation effect on Th4+ extraction by N,N,N',N'-tetraoctyldiglycolamide (TODGA)/1-ethyl-3-methylimidazoliumbis (trifluoromethylsulfonyl)imide ([C(2)mim][NTf2]) and TODGA/dodecane was evaluated through the quantitative analysis of TODGA content and identification of the radiolytic products. In addition, the density functional theory (DFT) calculations of extractability for the first time. The Th4+ partitioning of TODGA/[C(2)mim][NTf2] from 0.01 M HNO3 was near 98.6% at 1000 kGy, which was much higher than that in TODGA/dodecane (16.3%). The content of TODGA in diluent after irradiation was quantified using UPLC-Q-TOF-MS. The results showed that the [C(2)mim][NTf2] did not have the ability to protect the TODGA molecular comparing with the dodecane. However, TODGA in [C(2)mim][NTf2] prefers to react with the [C(2)mim](+) radical under g-radiation, and that in dodecane prefers degradation according to radiolytic products identification. Moreover, the DFT calculations presented that the substituted compounds formed in TODGA/[C(2)mim][NTf2] was responsible for partially keeping the extraction ability for Th4+.