Pr（Ⅳ）在二乙三胺五乙酸水溶液中稳定性的研究

Studies on the Stability of Pr(Ⅳ) in Diethylenetriaminepentaacetic Acid Aqueous Solution

Ｐｒ（Ⅳ，Ⅲ）碱式碳酸盐溶于一定浓度和ｐＨ值的二乙三胺五乙酸（ＤＴＰＡ）水溶液中，形成黄色Ｐｒ（Ⅳ）－ＤＴＰＡ配合物．测得该配合物组成比Ｐｒ（Ⅳ）：ＤＴＰＡ＝１：１．该配合物溶液在２７０ｎｍ附近有一特征宽带吸收峰．Ｐｒ（Ⅳ）在ＤＴＰＡ水溶液中的动力学稳定性与无螯合剂时相比较，至少提高了１０７倍，Ｐｒ（Ⅳ）的还原反应为拟一级反应．

The Pr(Ⅳ,Ⅲ) basic carbonates are soluble in diethylenetriaminepentaacetic acid (DTPA)aqueous solution to yield an yellow complex Pr(Ⅳ)-DTPA. The complex composition ratio of Pr (Ⅳ)-DTPA is 1: 1,and it shows a broad characteristic absorption band at 270 nm. Compared with no chelator the stability of Pr(Ⅳ) in DTPA aqueous solution is more than 107, The reduction kinetics for Pr(Ⅳ) in DTPA aqueous solution is pseudo first-order reaction.