微波消解-ICP-MS法同时测定小麦中铅、镉、铬、砷、汞含量

Simultaneous Determination of Lead,Cadmium,Chromium,Arsenic and Mercury in Wheat by ICP-MS with Microwave Digestion

以硝酸和过氧化氢为混合消解液,对小麦籽粒样品进行前处理,建立了微波消解-电感耦合等离子体质谱法(ICP-MS)同时测定小麦中重金属铅、镉、铬、砷、汞含量的分析方法。样品采用10 mL硝酸和2 mL过氧化氢的消解溶液体系,微波消解后稀释定容,在已优化选定的仪器工作条件下采用ICP-MS测定。实验结果表明,在质量浓度范围内铅、镉、铬、砷、汞5种元素的线性相关系数均大于0.999。其中,5种元素方法检出限在0.0064~0.042μg/L,定量检出限在0.021~0.14μg/L,各元素的平均加标回收率在95.8%~103.8%之间,相对标准偏差(RSD%)<4.8%,并用该方法测定了小麦标准物质(GBW10011)中5种元素含量,测试结果均在标准物质参考值范围内。

Wheat grain samples were pretreated by microwave digestion with nitric acid and hydrogen peroxide as mixed digestion solution.A method for the simultaneous determination of heavy metals Pb,Cd,Cr,As and Hg in Wheat by microwave digestion-inductively coupled plasma mass spectrometry(ICP-MS)was established in this paper.The samples were digested by microwave with 10 mL nitric acid and 2 mL hydrogen peroxide,diluted to volume after microwave digestion,and determined by ICP-MS under the optimized working conditions.The experimental results show that the linear correlation coefficients of lead,cadmium,chromium,arsenic and mercury are greater than 0.999 in the concentration range.Among them,the detection limits of five element methods were 0.0064μg/L to 0.042μg/L,with the quantitative detection limits ranging from 0.021μg/L to 0.14μg/L,the average recovery of each element between 95.8%-103.8%,and the relative standard deviation(RSD%)less than 4.8%.The contents of five elements in wheat reference material(GBW10011)were determined by this method,and the test results were within the reference value range of reference materials.