微波消解-电感耦合等离子体质谱法测定粮食中12种重金属元素

ICP-MS Determination of 12 Heavy Metal Elements in Cereals with Microwave Assisted Sample Digestion

粮食样品用硝酸-过氧化氢微波消解处理,采用电感耦合等离子体质谱法测定样品溶液中12种重金属元素(砷、铅、镉、硒、铬、铊、锰、镍、铜、铀、钴、钒)的含量。采用内标法消除基体的影响。方法的检出限(3S/N)在0.092~17.5pg·g-1之间。方法的加标回收率在88.1%~118%之间,相对标准偏差(n=5)小于6.0%。方法用于鸡肉标准物质(GBW 10018)中重金属含量的测定,测定值与认定值相符。

The sample of cereals was digested with HNO3 and H2O2 in a microwave digestion system,and the contents of 12heavy metals(i.e.As,Pb,Cd,Se,Cr,Tl,Mn,Ni,Cu,U,Co and V)in the sample solution were determined by ICP-MS.The interferences of the matrix elements were eliminated by internal standard.Detection limits(3S/N)of the method found were in the range of 0.092-17.5pg·g-1.Tests for recovery were made by standard addition method,giving values of recovery in the range of 88.1%-118% with RSD′s(n=5)less than 6.0%.In the analysis of CRM of chicken(GBW 10018)by the proposed method,the results obtained were in consistency with the certified values.