Laboratoire de Radioécologie, Département de chimie, Université Laval, 1045 Avenue de la Médecine, Québec, QC, Canada, G1V 0A6.
Talanta. 2011 Dec 15;87:8-14. doi: 10.1016/j.talanta.2011.08.062. Epub 2011 Sep 10.
This paper describes a novel strategy for actinide separation by extraction chromatography with Np(III) valence adjustment. Neptunium(IV) was reduced to Np(III) using Cr(II) and then selectively separated from uranium (IV) on a TEVA resin. After elution, Np(III) was retained on a DGA resin in order to remove any detrimental chromium impurities. Neptunium(III) formation was demonstrated by the complete and selective elution of Np from TEVA resin (99 ± 7%) in less than 12 mL of 9M HCl from U(IV) (0.7 ± 0.7%). It was determined by UV-visible and kinetic studies that Cr(II) was the only species responsible for the elution of Np(IV) as Np(III) and that the Cr(II) solution could be prepared from 2 to 30 min before its use without the need of complex degassing systems to prevent the oxidation of Np(III) by oxygen. The methodology proposed here with TEVA/DGA resins provides removal of Cr(III) impurities produced at high decontamination factors (2.8 × 10(3) and 7.3 × 10(4) respectively).
本文提出了一种通过萃取色层法分离锕系元素的新策略，该方法通过调节 Np(III) 的价态进行萃取。采用 Cr(II) 将四价锎还原为三价锎，然后在 TEVA 树脂上从铀(IV)中选择性地分离出来。洗脱后，Np(III)被保留在 DGA 树脂上，以去除任何有害的铬杂质。通过从 U(IV)中以小于 12 mL 的 9M HCl 完全和选择性地洗脱 Np(99±7%)，证明了 Np(III)的形成，洗脱 Np(IV)的 Cr(II)的量为 0.7±0.7%。通过 UV-可见分光光度法和动力学研究确定，Cr(II)是唯一负责洗脱 Np(IV)为 Np(III)的物种，并且可以在使用前 2 至 30 分钟内制备 Cr(II)溶液，而无需复杂的脱气系统来防止 Np(III)被氧气氧化。本文提出的使用 TEVA/DGA 树脂的方法可去除高去污因子（分别为 2.8×10(3)和 7.3×10(4)）下产生的 Cr(III)杂质。
