电感耦合等离子体质谱法测定果蔬中13种金属元素

Determination of 13 kinds of metal elements in fruits and vegetables by inductively coupled plasma mass spectrometry

目的：建立电感耦合等离子体质谱法（inductively coupled plasma mass spectrometry, ICP-MS）和在线内标法测定果蔬中铅（Pb）、砷（As）、镉（Cd）、铜（Cu）、铬（Cr）5种重金属元素及钠（Na）、钾（K）、钙（Ca）、锌（Zn）、硒（Se）、镁（Mg）、铁（Fe）、锰（Mn）8种微量元素的方法。方法对样品微波消解的功率和进样酸度进行优化,果蔬样品经微波消解后,进行ICP-MS测定,并对方法的线性关系、准确度、精密度和定量限进行考察。结果选择微波消解仪的功率为1600 W,进样酸度选择3%的硝酸体系。13种元素标准品的标准曲线的相关系数r≥0.9991,重金属元素的方法检出限为0.5μg/L,微量元素的方法检出限为10μg/L。13种元素的加标回收率为79.2%~91.6%,相对标准偏差小于5%,符合GB/T 27404-2008中的要求。结论本方法快速、准确、灵敏度高,可用于果蔬中重金属元素及微量元素的测定。

Objective To establish a method for determination of 5 kinds of heavy metals （Pb, As, Cd, Cu, Cr） and 8 kinds of trace elements （Na, K, Ca, Zn, Se, Mg, Fe, Mn） in fruits and vegetables by inductively coupled plasma mass spectrometry （ICP-MS） and online internal calibration method. Methods The power of the microwave digestion and sample acidity were optimized, and the samples were detected by ICP-MS after microwave digestion. At the same time, the linear relation, accuracy, precision and quantitative limit of the method were investigated. Results The appropriate power of the microwave digestion instrument was 1600 W, and the sample acidity was selected 3%. The correlation coefficients （r） of standard curves of 13 kinds of elements standard were greater than 0.9991, and the detection limits of heavy metals and trace elements were 0.5 μg/L and 10 μg/L, respectively. The recoveries of 13 kinds of elements were ranged from 79.2% to 91.6% with the relative standard deviations （RSDs） less than 5%, which met the requirements of GB/T 27404-2008. Conclusion The method is rapid, sensitive and accurate, which can be used for the determination of heavy metal elements and trace elements in fruits and vegetables.