尿样中铀同位素的ICP-MS快速测量技术研究

核事故状态下的应急处理，要求对环境介质中的放射性核素进行快速分析。尿样中铀同位素测量作为内照射剂量评价的主要手段，其分析效率越高，则对核事故中涉铀人员的安全救治越及时、有效。而尿样中其它无机离子是铀含量的106倍，导致ICP-MS测量过程中尿盐堵塞进样毛细管。为降低样品的含盐量并获得较好的检测结果，本文对样品预处理过程进行优化。采用先加热氧化去除有机物，再进行1～10倍稀释后测试样品的铀同位素丰度及浓度。结果表明：将25 mL样品稀释至100 mL后效果最佳，分析方法不确定度为5.4 %，回收率95 %~105 %。

Rapid determination uranium isotope in urine by ICP-MS

Urine uranium isotope determination is the basement of internal dose assessment. However, the urine of other inorganic ions is 106 times than that of uranium. During the ICP-MS analysis, sampling tubes and syringes were clogged by a high percentage of dissolved solids. To decrease the dissolved solids and improve the data quality, the sample preparation was optimized. Firstly, the thermal oxidation was used to remove organic matter. Then a proportion dilution method was used to prevent clogging of sampling tubes and syringes. The results show that 25 mL diluted to 100 mL has the best result. The relative standard uncertainty and recovery of methods were 5.4% and 95%~105%, respectively. With this method, rapid quantitative analysis was achieved.