内蒙古锡林郭勒盟饮用水中铀含量和铀同位素丰度分析

Determination of uranium concentrations and isotopic ratios in drinking water in Xilingol League of Inner Mongolia by ICP-MS

目的采集内蒙古锡林郭勒盟饮用水中铀含量和铀同位素丰度数据。方法采集内蒙古锡林郭勒盟有代表性的饮用水，利用电感耦合等离子体质谱（ICP—MS）法分析样品中U含量以及。^234U／^238U与 ^235U／^238U同位素丰度。结果样品中U浓度范围2．73～18．9μg／L，平均值为8．20μg／L；^234U／^238U的范围7．513×10^-5- 3．003×10^-4，测量的相对不确定度（RSD）小于0．5％；^235U／^238U的范围7．196×10-3～7．391×10^-3，测量的相对不确定度（RSD）小于0．2％。结论东乌旗自来水样品中U含量高于世界卫生组织饮用水中U含量的限值（15μg／L）；饮用水中的铀主要来源于天然环境；水样品中 ^234U被不同程度的富集。

Objective To ascertain the uranium concentrations and uranium isotopic ratios in drinking water in Xilingol League, the Inner Mongolia Autonomous Region. Methods Drinking water samples were collected in Xilingol League, the Inner Mongolia Autonomous. Region inductively coupled plasma mass spectrometry （ICP-MS） was applied to determine the concentration of uranium and uranium isotope abundance. Results The uranium concentrations in all samples were in the range of 2.73 - 18.9 μg/L, with an average of 8.20 μg/L. The ^234U/^238U isotope ratio varied from 7. 513 ×10^-5 to 3. 003 ×10^ -4 and ^235U/^238U from 7. 196 x 10-3 to 7. 391 ×10^-3. The relative standard deviation （RSD） was less than 0. 5% for ^234 U/^238U and 0. 2% for ^235 U/^238U. Conclusions The uranium concentration in samples collected from Dongwuqi was high than 15 μg/L, whih is the limit given by World Health Organization （WHO）. The uranium in drinking water originates from the natural environment. The ^234 U is enriched in drinking water.