电感耦合等离子体质谱法测定中国食品中钍和铀

采用电感耦合等离子体质谱 ( ICP-MS)对中国 1 0类食品中痕量 Th和 U进行了研究。选择了最佳仪器测定参数 ,选用铼 ( Re)为内标元素补偿基体效应和仪器灵敏度漂移。用 HNO3 与 HCl O4混合酸消解样品 ,不须分离富集 ,用 ICP-MS可直接测定中国 1 0类食品中 Th和 U。方法检出限为 5 .7ng/L ( 2 3 2 Th) ,1 0 .4ng/L( 2 3 8U) ( 3σ,n=6)。同时对 NIST SRM 1 5 48标准参考物质进行分析 ,测得值与标准参考值相吻合。

Determination of Thorium and Uranium in Chinese Foods by Induced Coupled Plasma Mass Spectrometry

The trace Th and U in 10 kinds of Chinese foods are determined by induced coupled plasma mass spectrometry (ICP MS). The optimum instrument parameters have been selected. Re is used as an internal standard element to compensate for non spectrum interferences arising from matrix elements in the solution and sensitivity drift. Detection limits are 5.7 ng/L for Th and 10.4 ng/L for U (3σ, n =6). The accuracy of this method is corrected using standard sample NIST SRM 1548 as total diet. The analytical results are in good agreement with certified values. On the basis of strict quality control, grain, bean, potato, meat, egg, aquatic product, milk, vegetable, fruit and sugar samples are digested by mixed nitric acid and perchloric acid and determination of U and Th in sample solution by ICP MS directly without separation and enrichment procedure.