电位法测定微量铀的研究

Investigation of Potentiometric Determination of Trace U(Ⅵ) with UO_2^(2-)-CO_3^(2-) Systems

本文用电位法研究了UO_2^(2+)-CO_3^(2-)(HCO_3^-)体系的配位反应,发现体系的电位变化在0～24μgU(Ⅵ)/mL范围内与U(Ⅵ)浓度间存在良好的线性关系。据此提出了一种测定微量铀的方法,确定了测定的最佳条件;借助离子交换分离富集,可准确测定的浓度下限为0.1μg/mL。测定了实验室中模拟含铀废水中铀(Ⅵ)含量,得到了满意结果。回收率为94.3％～105.6％。

The coordination reaction ofUO_2^(2-)-CO_3^(2-)systems are studied potentiometrically, and a method for potentiometric determination of trace U(VI)has been established based on this reaction. The calibration graph is linear for 0-24μg U(VI)/mL under given conditions. 2.4μg U(VI)/mL can be determined accurately within dev. of≠±5% , and the detection limit is lowered to 0.1μg U(VI)/mL with the aid of ion exchanging enrichment. The method has been used for the determination of trace U(VI)in simulated waste waters, the recovery is between 94.3 and 105.6% and the results are satisfactory.