液体激光荧光法测定外排水中铀浓度的方法优化

Optimization of Analytical Method for Determination of Uranium in External Drainage by Liquid Laser Fluorescence

在用液体激光荧光法测定外排废水中的微量铀时发现,样品保存方式、基体离子干扰及样品取样体积均影响测定结果的准确度。为此,采用标准加入法对干扰元素及取样体积等进行试验分析,结果表明:测定浑浊水样前,须先过滤再酸化保存;当样品中的ρ(Ca^2+)>16.00μg/mL,ρ(Cl-)>610.00μg/mL时,干扰铀的测定;将样品稀释25倍可有效降低基体干扰;液体激光荧光法分析铀的测定下限是0.08μg/L。

In the determination of trace uranium in effluent by liquid laser fluorescence method,there are problems such as sample preservation method,matrix ion interference and sample sampling volume affect the accuracy of measurement results.For this reason,the standard addition method is adopted to carry out experimental analysis on interference elements and sampling volume,etc.The results show that turbid water samples must be filtered before acidification and preservation,when Ca^2+mass concentration is higher than 16.00μg/mL,the Cl-mass concentration is higher than 610.00μg/mL,it interferes with the determination of uranium.Diluting the sample 25 times can effectively reduce matrix interference.The lower limit of uranium determination by liquid laser fluorescence analysis is 0.08μg/mL.