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建立了沉淀分离-密闭消解-电感耦合等离子体质谱法测定铬铁矿中铂族元素的新方法.采用硫磷混酸溶样 (1:2, V/V), 以硫酸肼为还原剂, 实现了硫脲对包括Os在内的全部铂族元素的沉淀富集, 沉淀经密闭溶样技术快速消解后接ICP-MS测定.试验中筛选出HBr来消除Os的记忆效应, 并考察了Os在王水介质中的稳定性.结果表明:铂族6个元素的线性相关系数均在0.999以上, 对标准物质GBW07292平行测定6次的相对标准偏差 (RSD, n=6) 在2.7％～8.4％之间, 方法检出限 (3σ) 在0.055～0.21ng/g, 采用国家一级标准物质GBW07201, GBW07202, GBW07292进行方法验证, 测定值与认定值基本一致.“,”An analytical method was developed for determination of platinum group elements in chromite by inductively coupled plasma mass spectrometry (ICP-MS)with precipitation treatment and closed-digestion. The chromite sample was successfully digested using H2 SO4+ H3 PO4 (V: V = 1: 2).Hydrazine sulfate was used as reducing agent to prevent the oxidation of Os when platinum group elements were precipitated with thiourea. Then, the precipitate was digested with closed-digestion using aqua regia. The memory effect of Os was eliminated by flushing through HBr and the stability of Os in aqua regia was also investigated. The study showed that: the correlation coefficients of calibration curves of 6 platinum group elements were higher than 0. 999, RSD (n = 6)of the analysis results of platinum group elements in standard reference material GBW07292 ranged from 2. 7％-8. 4％, and the detection limits were 0. 055-0. 21 ng/g. The method was applied to the determination of platinum group elements in GBW07201, GBW07202 and GBW07292 with satisfactory results.