微波灰化电感耦合等离子体质谱法测定小麦中6种金属元素含量

Determination of 6 kinds of metal elements in wheat by microwave ashing and 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)同时测定小麦中Pb、Cd、Cr、Ni、Cu、Zn 6种元素含量的分析方法。方法小麦样品用微波灰化处理,用硝酸溶解残渣,以超纯水定容,用ICP-MS进行测定,并对方法的线性范围、检出限、精密度和回收率进行了考察。结果 6种元素在一定范围内线性关系良好,相关系数均大于0.999,方法检出限为0.04～0.4μg/L。各元素加标回收率在84.5%～123.8%之间,测定结果的相对标准偏差(relative standard deviation, RSD)在1.3%～4.5%之间。结论该方法快速、准确、灵敏度高,适用于小麦中金属元素的同时测定。

Objective To establish a method for determination of 6 kinds of metal elements including Pb, Cd, Cr Ni, Cu and Zn in wheat by inductively coupled plasma-mass spectrometry(ICP-MS). Methods The wheat samples were ashed by microwave ashing system. The residue was resolved with HNO3 followed by dilution with ultrapure water and detected by ICP-MS. The linear relation, accuracy, precision and limits of detection of this method were investigated. Results The 6 kinds of elements had good linear relationships in the certain range, and the correlation coefficients were all greater than 0.999. The limits of detection were 0.04-0.4 μg/L. The recovery rates were 84.5%-123.8%, with the relative standard deviations(RSDs) of 1.3%-4.5%. Conclusion This method is rapid, accurate and sensitive, which is suitable for the determination of the metal elements in wheat.