电感耦合等离子体质谱法测定滤膜中稀土金属方法前处理的优化

Optimization of pretreatment of rare earth metals in filter membrane by inductively coupled plasma mass spectrometry

目的采用电感耦合等离子体质谱仪(ICP-MS)对滤膜中的多种稀土金属元素含量进行测定。对《工作场所空气中有毒物质测定第34部分:稀土金属及其化合物》(GBZ/T 300. 34-2017)所使用的前处理方法进行调整改进,建立简便、准确的试验方法。方法分别采用国家标准法和水浴法进行样品前处理,比较2种前处理方法的检出限、重复性、加标回收率、消解时间和试剂消耗量。结果国家标准法处理后回收率为94. 27%~108. 97%,RSD为1. 15%~2. 36%,消解时间约12 h。水浴法处理后回收率为93. 70%~103. 82%,RSD为1. 59%~2. 68%,消解时间<1 h。2种前处理方法在重复性和加标回收率上具有较好的一致性。结论改进后的水浴法前处理方法操作简便、快速,同时能减少对试验人员的伤害和酸污染的形成。该改进方法适用于工作场所空气中稀土金属及其化合物的测定。

Objective The content of rare earth metals in filter membrane was determined using inductively coupled plasma mass spectrometry( ICP-MS). An effective and accurate method was established to improve the pretreatment method in Determination of Toxic Substances in Workplace Air-part 34: Rare Earth Metals and Their Compounds( GBZ/T 300. 34-2017).Methods The samples were pretreated by standard method and water bath digestion method. The two pretreatment methods were evaluated by detection limit,repeatability,recovery rate,digestion time and the reagent consumption. Results The recovery rate of the standard method was within 94. 27%-108. 97%,the relative standard deviation was within 1. 01%-1. 83%,and the digestion time was about 12 hours. The recovery rate of water bath digestion method was within 93. 70%-103. 82%,the relative standard deviation was within 1. 59%-2. 68%,and the digestion time was less than 1 hour. The recovery rate and relative standard deviation of the two methods showed a good agreement. Conclusion The improved method with new sample pretreatment procedure was more convenient and faster for operation. Furthermore,it reduced the harm both to lab operators and the environment. The optimized method is suitable for determining the content of rare earth metals and its compounds in workplace air.