氧化铝柱预分离-同位素稀释-电感耦合等离子体质谱法测定高温合金中痕量硫

Determination of trace sulfur in superalloy by alumina column pre-separationisotope dilution-inductively coupled plasma mass spectrometry

采用Al_(2)O_(3)柱预分离,将痕量硫与复杂基体元素分离并浓缩,同时与电感耦合等离子体质谱(ICP-MS)联用,采用同位素稀释质谱法,实现了对0.0006%以下硫含量的准确测定。采用Al_(2)O_(3)柱净化分离的方法解决基体效应和由HClO_(4)引入的空白问题;以O_(2)作为反应气体,通过质量转移方式解决质谱干扰问题,同时对仪器参数进行了优化。在优化条件下,方法检出限和定量限分别为0.00003%和0.00008%。按照实验方法对高温合金标准物质的测定结果与认证值一致,对高温合金实际样品0.0001%含量硫的加标回收率为92.0%,相对标准偏差为4.7%。使用所建立的方法对硫含量在0.0006%及以下的实际样品进行分析,结果与红外吸收法一致。

Trace sulfur were separated from complex matrix elements and concentrated by alumina column preseparation,and the accurate determination of sulfur content below 0.0006%was realized by isotope dilution mass spectrometry combined with inductively coupled plasma tandem mass spectrometry(ICP-MS).The matrix effect and the blank introduced by perchloric acid were solved by alumina column pre-separation.Using O_(2) as reaction gas,mass transfer method was adapted to solve the mass spectrometry interference.In addition,the instrument parameters were optimized.Under the optimum conditions,the limit of detection and the limit of quantification were 0.00003%and 0.00008%,respectively.According to the experimental method,the determination result of the standard substance of superalloy was consistent with the certified value.The spiked recovery rate of 0.0001%sulfur content in actual sample of superalloy was 92.0%,and the relative standard deviation was 4.7%.The method was used to analyze the samples with sulfur content less than 0.0006%,and the results were consistent with those determined by infrared absorption method.