ICP-MS对我国9种典型土壤中铀含量及^(235)U/^(238)U比值的分析  

Study of Uranium Concentration and ^(235)U/^(238)U Isotopic Ratio in Nine Kinds of Soils in China

作　　者：郭志英[1] 梁月琴[1] 李娟[1] 于水[1] 

机构地区：[1]军事医学科学院生物医学分析中心,北京100850

出　　处：《中国辐射卫生》2011年第1期30-32,共3页Chinese Journal of Radiological Health

基　　金：国家科技部创新方法研究项目(2008IM021500)

摘　　要：目的研究采用不同的土壤预处理方法联合电感耦合等离子体质谱(ICP-MS)技术,同时分析土壤中铀含量及235U/238U比值的方法,并且分析我国9种典型土壤中的铀含量及235U/238U比值。方法分别采用微波消解、灰化法和直接酸溶法对土壤样品进行预处理,通过ICP-MS同时测定土壤中的铀含量和235U/238U。采用建立的方法分析我国9种土壤中的铀含量及235U/238U。结果铀元素在0～400μg/kg线性良好(r=0.9999),精密度较高(RSD为0.11%～2.37%)。土壤样品预处理方法中,以HNO3+HF+H2O2为消解试剂进行微波消解得到的结果与推荐值吻合较好(相对误差为5.2%),土壤中铀回收率为100.6～109.0%,最低检测限为0.86 ng/kg。我国9种土壤中的铀浓度为1.2～4.0 mg/kg,各种土壤中的235U/238U均接近天然水平(0.00 725)。结论本研究建立了微波消解与ICP-MS联合应用,同时分析土壤中的铀含量及235U/238U的方法,该方法线性范围宽、准确度高、检测限低,采用该方法检测的我国9种土壤中的铀含量和235U/238U均在正常水平。Objective The uranium concentration and235 U/238U isotopic ratio in nine kinds of typical soils in China were determined by different digestions followed by inductively coupled plasma mass spectrometry （ICP - MS） technology. Methods To prepare the soil samples with microwave digestion, ashing method and the hot acid - dissolution method separately, and the uranium concentration and 235 U/23sU isotopic ratio in soil samples are detected simultaneously using ICP -MS. Uranium concentration and235 U/238 U ratio of China＇ s nine typical soils are detected by the above - mentioned method. Results When uranium concentration between 0 and 400 pLg/kg, the cps ratio of U and Pt is linear with the uranium concentration （ r = O. 9 999）. Comparing with different soil pretreatment methods, the test results have good agreement with certified values by microwave digestion method with HNO3 ＋ HF ＋ H2 O2 （relative error is 5.2% ）. Uranium recovery is 100.6% ~ 109.0%, and the method detection limit is 0.86 ng/kg. The uranium concentrations in nine kinds of soils in China are 1.2 ~ 4.0 mg/ kg. The 235 U/23s U isotopic ratio of them is close to the natural 235 U/238 U ratio （0.00725）. Conclusion The analysis method to determine the uranium concentration and 235 U/23Su isotopic ratio in the soil turns out to be accurate, sensitive and efficient, which applies the microwave digestion and ICP - MS technique. The uranium concentration and 235 U/238U ratio in nine kinds of soils in China detected using the method are all in normal range.

关 键 词：电感耦合等离子体质谱 土壤 铀235U/238U 

分 类 号：R145[医药卫生—公共卫生与预防医学]