Conroy Nathan A, Wylie E Miller, Powell Brian A
Environmental Engineering & Earth Science, Clemson University , Clemson, South Carolina 29625, United States.
Anal Chem. 2016 Apr 19;88(8):4196-9. doi: 10.1021/acs.analchem.6b00229. Epub 2016 Mar 28.
Preparation of relatively pure low concentration Pu(V) solutions for environmental studies is nontrivial due to the complex redox chemistry of Pu. Ozone gas generated by an inexpensive unit designed for household-use was used to oxidize a 2 × 10(-8) M Pu(IV) solution to predominantly Pu(VI) with some Pu(V) present. Over several days, the Pu(VI) in the solution reduced to Pu(V) without further reducing to Pu(IV). The reduction from Pu(VI) to Pu(V) could be accelerated by raising the pH of the solution, which led to an immediate conversion without substantial conversion to Pu(IV). The aqueous Pu was found to be stable as predominately Pu(V) for greater than one month from pH 3-7; however, at circumneutral pH, a sizable fraction of Pu was lost from solution by either precipitation or sorption to the vial walls. This method provides a fast means of preparing Pu(V) solutions for tracer concentration studies without numerous extraction or cleanup steps.
由于钚复杂的氧化还原化学性质，制备用于环境研究的相对纯净的低浓度钚（V）溶液并非易事。使用一种为家庭用途设计的廉价装置产生的臭氧气体，将2×10⁻⁸ M的钚（IV）溶液氧化为主要含钚（VI）且含有一些钚（V）的溶液。在几天时间里，溶液中的钚（VI）还原为钚（V），而没有进一步还原为钚（IV）。通过提高溶液的pH值，可以加速钚（VI）向钚（V）的还原，这会导致立即转化，而不会大量转化为钚（IV）。发现水相中的钚以主要为钚（V）的形式稳定存在超过一个月，pH范围为3至7；然而，在接近中性的pH值下，相当一部分钚会通过沉淀或吸附到小瓶壁上而从溶液中损失。这种方法为制备用于示踪剂浓度研究的钚（V）溶液提供了一种快速手段，无需大量的萃取或净化步骤。
