微波消解-电感耦合等离子体质谱法同时测定出口蔬菜中15种无机元素

Simultaneous determination of 15 inorganic elements in export vegetables by microwave digestion-inductively coupled plasma mass spectrometry method

摘要：本文建立了电感耦合等离子体质谱同时测定出口蔬菜中Mg、Ti、V、Cr、Mn、Fe、Ni、Cu、Zn、As、Se、Cd、Tb、Hg和Pb共15种无机元素的分析方法。样品在硝酸过氧化氢体系中经微波消解后直接上样分析，采用氦气碰撞模式消除了多原子离子质谱干扰，以Sc、Rh、In、Ir作为内标元素校正了质谱分析中基体效应并补偿了信号漂移。结果表明：测定质量浓度在0～50mg·kg^-1。范围内，各元素呈现良好的线性关系，r≥0．9995；检出限为0．003-37．21μg·kg^-1。选择国家标准物质豆角（GBW10021）、芹菜（GBW10048）和大葱（GBW10049）验证方法的可靠性，待测元素测定结果均在标准值允许范围内，日间相对标准偏差（n=6）在1．4％-19．4％之间。应用该方法测定了连云港蔬菜基地10种出口蔬菜，结果发现As、Cd、Ph、Cr、Hg含量均符合国内外相关标准中的限量要求。样品的测定结果为掌握连云港出口蔬菜中各种元素的含量水平，指导基地蔬菜的种植与出口提供了理论依据。

An analytical method based on inductively coupled plasma mass spectrometry（ICP-MS） was developed for the simultaneous determination of 15 inorganic elements （ Mg, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd, Tb, Hg and Pb）in export vegetables.After the samples were pretreated by microwave digestion under HNQ- H2O2, octopole collision-reaction system（ORS） was used to eliminate the polyatomic interferences.Sc, Rh, In and Ir were used as internal standard elements to compensate matrix effect and signal drift. The results indicated that the concentrations and responses of each element showed a good linear relationship in the range of 0-50 mg·kg^-1 with correlation coefficients higher than 0.9995.The limits of detection（LOD） were in the range of 0.003 - 37.21 pg. kg-＇. The established method was validated by analyzing the National Standard Reference Material of Beans （GBW10021） ,Celery（GBW10048）and Green Chinese Onion（ GBW10049）.The relative standard deviation values of reproducibility（ n = 6）were 1.4% ~19.4%, and the analysis results were all in material reference range.Among the 15 elements,As, Cd, Pb, Cr and Hg were lower than relevant limit requirements. Furthermore, the elements content level of export-vegetables from Lianyungang was basically established,which could provide theoretical basis for the cultivation and export of vegetables.