ORS-ICP-MS法测定热带水果中微量元素

Determination of trace elements in tropical fruit by inductively coupled plasma mass spectrometry with octopole reaction system

采用微波消解-八极杆碰撞/反应池(ORS)-电感耦合等离子体质谱仪(ICP-MS)测定热带水果中Mg、Ca、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Cd、Pb等12种微量元素的含量。样品用硝酸+双氧水分解后,试液直接用ICP-MS法同时上述微量元素。应用ORS技术,有效地消除了多原子离子对待测元素的干扰,选用Sc、Y、In、Bi等元素作内标混合液校正基体效应和信号漂移,确定了实验的最佳测定条件。结果表明,该方法对12种待测元素的检出限在0.001～0.093μg/L之间,相对标准偏差(RSD)均小于3.32%。该方法简便、快速、准确,可以用来进行热带水果的质量控制和安全评价。

An analysis method of microwave digestion and inductively coupled plasma-mass spectrometry （ICP-MS） with octopole reaction system （ORS） were established for the determination of 12 elements （Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Pb） in tropical fruit. Samples were decomposed by HNO3 and H2O2 followed by dilution with ultrapure water then the above 12 elements in the solution was analyzed directly by ICP-MS. The use of ORS can eliminate the interference of polyatomic ions dramatically. Sc, Y, In and Bi as internal standard elements were used to compensate matrix effect and signal drift. The optimum conditions for the determination was tested and discussed. Under the optimal conditions, the detection limits of the 12 elements was in the range of 0.001-0.093 μg/L and the relative standard deviation （RSD） less than 3.32%, which showed that the method was very precise. The technique was applied for the quality control and safety evaluation of tropical fruit.