MC-ICP-MS测定积累植物中Cu、Zn同位素的化学分离方法研究

Separation of Cu and Zn in accumulators for isotope determination by MC-ICP-MS

多接收器等离子体质谱仪(MC-ICP-MS)高精度同位素组成的准确测定,依赖于对样品中待测元素的分离纯化。本研究比较了两种溶样方法对有机样品积累植物海州香薷的消解效果,检测了AGMP-1阴离子交换树脂对样品中Cu、Zn的分离效果,并测定了样品中的Cu、Zn同位素组成。结果表明:①两种不同溶样方法均能有效地破坏积累植物海州香薷样品中的有机质;②AGMP-1树脂能有效分离纯化植物中的Cu、Zn,经过AGMP-1树脂一次交换分离和二次交换分离的植物根样品的Cu接收液基体元素的去除基本没有差别,经过一次交换分离的Zn溶液,基体元素也基本除去,可以用于MC-ICP-MS对Cu、Zn同位素组成高精度的测定;③Cu、Zn同位素组成测定误差不大于仪器的长期重现性,表明样品的化学处理过程、各离子交换树脂柱分离交换过程和仪器测试过程均有很好的重现性,符合样品测定的要求。

Accurate determination of Cu and Zn isotopes using MC-ICP-MS requires an adequate separation of the elements from bulk samples. Two methods for accumulator dissolution have been investigated through assessments of the purity of Cu and Zn solutions after ion exchange chromatography using AG MP-1 resin, the repeatability of the chromatographic columns, and the consistency of Cu and Zn isotope determination for samples dissolved and purified using different procedures. The results show that： ① Both methods are effective to destroy the organic matter of plant samples; （2） The AG MP-1 resin can been used to separate Cu and Zn from the organic sample after effective dissolution, and it is enough for the sample to get the accurate value of isotope composition after one exchange using ACT MP-1 resin; ③ The standard error of Cu and Zn isotope composition is smaller than the repeatability over a long time, it shows that whole chemical procedure, the separation of resin and the condition of instrument are suitable.