空气中痕量铀的现场光度法测定

作为一种天然放射性金属元素，铀及其化合物可以地气为分散系，以气溶胶形式稳定存在并随空气迁移。气相中铀可经多种途径对人体造成放射性危害，而其浓度变化与该区域核能开发与利用有关。因此，对空气中铀的快速现场检测具有现实意义。采用普通气泵对低品位铀矿石上方的空气进行采样，并以2.0 mol·L-1硝酸溶液对气体进行吸收，向溶液中添加固体试剂包，对溶液中微量铀进行显色后以手持式光度计进行现场光度分析。结果表明：对于普通低品位铀矿石样品，空气中铀含量可用本方法检出，该方法多次测定的RSD为1.72%，其结果与ICP-MS分析结果一致。将该方法用于区分铀矿石和其他矿石，具有成本低廉，操作方便，结果准确可靠等优点。

Detection of Trace Uranium in Air with Field Spectrometry

As a natural radioactive element, uranium and its compounds exist as aerosol and transfer in air. In gas phase, uranium can cause various kinds of radioactive damage to human body. The change in its concentration in a local area is related to the exploration and utilization of nuclear energy. Therefore, the development of field method for rapid uranium detection in air sample is very important. In this contribution, the air samples over uranium ores collected by a general pump was absorbed with 2.0 mol·L-1 nitrate and then reacted with solid reagent kit. When the reaction between trace uranium and chromogenic reagent was finished, the homemade portable photometer was used to measure the absorbance. The results showed that the concentration of uranium in air samples over low grade uranium ores can be successfully determined by the present method and the values agree with that obtained by ICP-MS. The RSD measured by the new method was 1.72%. The application of the new field spectrometry in discriminating uranium ores from other ores has the potential advantages of easy operation, cost-saving and high accuracy.