用双同位素稀释质谱法测定高放废液中的微量铀,采用TBP/Kel-F粉反相分配色层法分离铀,双稀释剂分别为浓缩~(235)U及~(238)U,铀同位素丰度比的质谱测定相对标准误差优于0.1%,化学处理及质谱测定全流程铀的空白值为3×10~(-9)g,方法检测限对于铀为1×10~(-9)g,高放废液中微量铀测定结果不确定度为±2%。 Determination of uranium in high-level liquid waste by dual isotope dilution-mass spectrometry was performed. The uranium was separated by reversed-phase partition chromatography using TBP / Kel-F powder. The two diluents were concentrated 235 U and 238 U, The relative standard deviation of uranium isotope abundance ratio was better than 0.1%. The blank value of uranium in the whole process of chemical processing and mass spectrometry was 3 × 10 ~ (-9) g. The detection limit of this method was 1 × 10 ~ (- 9) g, uranium determination of high level waste liquid Uncertainty of ± 2%.