微波消解-电感耦合等离子体质谱法测定蔬菜中的重金属

目的建立测定蔬菜中砷、铅、镉、汞、铜多元素的电感耦合等离子体质谱法。方法样品经微波消解后,采用电感耦合等离子质谱法进行测定,选择~(45)Sc、~(72)Ge、~(115)In、~(209)Bi作为内标元素补偿基体效应,优化仪器参数,对该方法的检出限、线性范围、精密度和回收率进行考察,并对市售的8种蔬菜样品中5种元素同时进行测定。结果研究结果表明,砷、铅、镉、汞、铜5种元素线性关系良好,相关系数均大于0.995,检出限为0.001~0.05 mg/kg,相对标准偏差低于1.5%,不同样品基质加标回收率在82.5%~109.9%范围之间。结论本方法快速、灵敏、准确,适用于蔬菜中砷、铅、镉、汞、铜5种元素的同时测定。

Determination of heavy metal elements in vegetables by microwave digestion-inductively coupled plasma mass spectrometry

Objective To establish a method for the determination of arsenic (As), lead (Pb), cadmium (Cd), mercury (Hg) and copper (Cu) in vegetables by inductively coupled plasma mass spectrometry (ICP-MASS). Methods After microwave digestion, the samples were determined by ICP-MASS. The compensation matrix effects were calibrated by selecting 45Sc, 72Ge, 115In and 209Bi as internal standard elements, the instrument conditions were optimized and the detection limits, linear relationships, recoveries and precisions of the method were analyzed. The contents of 5 elements in 8 kinds of vegetable samples were measured. Results The results indicated that, 5 elements had good linear relationships with the correlation coefficients>0.995; the detection limits were 0.001~0.05 mg/kg; the relative standard deviations were less than 1.5%; and different matrix standard addition recoveries of samples were ranged from 82.5% to 109.9%. Conclusion This method is rapid, sensitive and accurate, and suitable for the simultaneous determination of As, Pb, Cd, Hg and Cu in vegetables.