ICP-MS混合模式测定植物性农产品中的9种痕量元素

Determination of Nine Trace Elements in Plant Samples by Inductively Coupled Plasma Mass Spectrometry in Mixed Mode

建立了ICP-MS混合模式测定蔬菜、水果、大米等植物性农产品中痕量元素的检测方法。样品经HNO3+H2O2消解,以74Ge、115In、209Bi作为内标溶液消除基体干扰,动能歧视型碰撞/反应池技术消除质谱干扰的方式测定植物性农产品中As、Hg、Pb、Cd、Cr、Se、Cu、Ni、Zn 9种痕量元素。结果表明:该方法的线性范围均超过2个数量级,r≥0.999 2;检出限为0.8～40μg.kg-1;相对标准偏差(RSD)为0.6%～5.8%。利用所建立的方法测定了大米粉(GBW10010)、菠菜(GBW10015)、苹果(GBW10019)3种标准物质,分析结果均在参考值范围内。方法简单、快速、准确,适用于批量样品中多元素的同时测定。

A method of inductive coupled plasnla mass spectrometry（ICP- MS） in mixed mode was established to determine the trace elements in plant samples, such as vegetables, fruit and rice. After digested by HNO3 ＋H2O2, nine trace elements of As, Hg, Pb, Cd, Cr, Se, Cu, Ni and Zn in the samples were analyzed by using the technology of the collision/reaction cell with kinetic energy discrimination （KED） to eliminate the interference of mass spectrometry. 74Ge, 115In and 209Bi were also used to eliminate the matrix interference. The results indicated that the linear range of the method was beyond two orders of magnitude and the linear correlation coefficient was not less than 0. 999 2. The limits of detection（LOD） were in the range of 0. 8 -40 μg/kg with RSDs of 0. 6% -5.8% . The established method was used to determine the three certified reference materials of rice flour （GBW10010） , spinach（GBW10015） and apple（ GBW10019）, and the analysis results were all in material reference range. The method was simple, rapid and accurate, and was suitable for the determination of muhi-elements in plant samples simultaneously.