With the development of nuclear power industry in our country, the needs for uranium will increase drastically. But as the uranium resource in uranium mines are very limited, much attention has been paid on the uranium recovery from other resources, such as sea water and high salinity brine. Accurate determination of uranium concentration is very important, if uranium recovery was performed on this complicate water. Trace uranium determination in high salinity brine, for instance, salt lake and intercrystalline bittern samples, was studied in present work by using ultraviolet fluorescence method. As the instrument is stable, the optimal conditions for uranium determination are found to be: pH = 2-12, added fluorescence-enhancing agent amount of 500 μL; to reduce the negative effect of impurity ions on uranium determination, both direct dilution and TBP extraction fluorescence methods are investigated. The procedure used for TBP extraction fluorescence method is confirmed by employing different solvents as TBP diluent, and the uranium recov-ery rate is determined to be 85%. Under the optimal conditions, both methods mentioned above were used for analyzing uranium concentration in salt lake and intercrystalline bittern samples. The obtained results were compared with those measured by inductively coupled plasma mass spectrometry (ICP-MS) method. Good consistency among the results is founded, which clearly shows that the method can be used for uranium determination in high salinity brine.%通过系统对比实验,建立了一种适合于盐湖水、晶间卤水等高矿化度液体样品中微量铀的测定方法——紫外荧光法.在确定仪器测量稳定性的基础上,给出紫外荧光法测定铀的最佳条件为样品pH=2～12,荧光增强剂用量为500μL.为减少杂质离子对铀测定的干扰,分别采用直接稀释荧光法及TBP萃取荧光法进行铀的测定,确定了TBP萃取荧光法测量高矿化度水样中微量铀的步骤,实验测得铀的萃取—反萃回收率约为85％.利用上述两种方法分析盐湖和晶间卤水样品中铀的质量浓度,所得结果与电感耦合等离子体质谱法(ICP-MS)测定结果无显著差别,说明该法可用于高矿化度水样中微量铀的测定.
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