地质样品中铼的密闭消解电感耦合等离子体质谱测定法

摘要

The optimal conditions for testing rhenium in geological samples using Inductively Coupled Plasma -Mass Spectrometry (ICP-MS ) method was discussed and the defects caused by the original testing method such as low sensi-tivity that couldn’ t meet the requirements of testing the geological samples with low rhenium content were successfully avoided .Considering the disadvantages of unstability and easy volatilization of Rhenium in acid solutions ,geological sam-ples were treated under closed-vessel digestion by nitric acid and H2O2 to avoid Rhenium decomposition .After the test method was confirmed ,several blank tests were carried out according to the test conditions and the sample treatment pro-cess .The detect limit for 3σ(standard deviation ) was 1 .60 ng/g ,and for 10σwas 5 .32 ng/g .The addition standard re-covery rate was 95 .8% to 101 .1% .Precision test was performed on China national standard material GBWO7238 .The relative standard deviation ( n=6 ) was 7 .3% .And then ,the method was applied to six different concentration levels of this standard material and the test results were in accordance with the certified value .Therefore this method can meet the requirement of testing rhenium in geological samples .%针对铼在酸性溶液中不稳定易挥发损失的缺点，采用硝酸、过氧化氢密闭中压消解处理，解决了铼的分解问题。探讨了等离子体质谱法测量地质样品中铼的最佳条件，解决了原测量方法灵敏度低，不能满足地质样品中低含量铼测定的缺陷。在试验方法确定的条件下，按照仪器测量条件及试样处理全过程进行数份空白试验，以3倍标准偏差计算仪器的检出限为1．60 ng／g ，10倍标准偏差计算方法的检出限为5．32 ng／g ；方法的加标回收率在95．8％～101．1％。对国家标准物质GBWO7238进行精密度试验，相对标准偏差（ n＝6）7．3％。方法应用于6个不同含量级别的国家标准物质中，铼的测量值与认定值相符，能够满足地质样品中铼的测量要求。