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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 the determination of Pb, As, Cd, Cu, Cr (Cr) in fruits and vegetables by inductively coupled plasma mass spectrometry (ICP-MS) and online internal standard method ), Five kinds of heavy metal elements and eight kinds of trace elements (Na, K, Ca, Zn, Se, Mg, Fe and Mn) method. Methods The microwave digestion power and injection acidity of samples were optimized. After microwave digestion, the samples of fruits and vegetables were determined by ICP-MS. The linear relationship, accuracy, precision and limit of quantification were also investigated. Results The power of the microwave digestion instrument was selected to be 1600 W. The sample acidity was chosen to be 3% nitric acid. The correlation coefficient of the standard curve of 13 kinds of elemental standards is r≥0.9991, the detection limit of heavy metal elements is 0.5μg / L, and the detection limit of trace elements is 10μg / L. The spiked recoveries of 13 elements ranged from 79.2% to 91.6% with relative standard deviations less than 5%, which met the requirements of GB / T 27404-2008. Conclusion The method is rapid, accurate and sensitive and can be used for the determination of heavy metal elements and trace elements in fruits and vegetables.