摘要
[Objective] This research aimed to establish an inductively coupled plasma mass spectrometry （ICP-MS） method for determination of five kinds of heavy metals （Pb, Cd, Cu, As and Hg） in Dendrobium candidium Wall. ex Lindl. [Method] The samples were digested in HNO3-H202 acids system by closed vessel microwave di- gestion. At the same time, internal standard was added to avoid the matrix effect. [Result] The five kinds of heavy meals all showed good linear relationships, and the correlation coefficients ranged from 0.998 2 to 0.999 9. The detection limits of the five kinds of heavy metals were in the range of 0.008-0.750 μg/L, while the stan- dard recovery rates were in the range of 90.4%-96.9%. The relative standard devi- ations ranged from 1.6% to 8.2%. The heavy metals in the Ginseng and Astragalus national standard samples were determined by the established ICP-MS method, and the results were in conformity with the standard values. [Conclusion] The established method has simple and convenient operation and accurate and reliable results, and it meets the requirements by determination of heavy metals in Dendrobium candididium Wall. ex Lindl.
[目的]建立电感耦合等离子体质谱（ICP-MS）法测定铁皮石斛中Pb、Cd、Cu、As、Hg等5种重金属元素的方法 。[方法]样品采用硝酸、双氧水混合体系进行微波消解,电感耦合等离子体质谱（ICP-MS）进行测定。同时为避免基体效应等影响,加入内标进行校正。[结果]5种重金属元素线性关系良好,相关系数为0.998 2~0.999 9,检出限范围为0.008~0.750μg/L。加标回收率为90.4%~96.9%,相对标准偏差为1.6%~8.2%。用该法测定国家标准物质人参和黄芪,测定结果均在标准参考值范围内。[结论]建立的方法操作简便快捷,结果准确可靠,满足铁皮石斛中重金属元素的测定要求。
