电感耦合等离子体质谱法测定谷类产品中7种元素

Determination of Seven Elements in Cereal Products by ICP-MS

为建立准确、快速地同时测定谷类产品中微量重金属元素含量的方法,采用电感耦合等离子体质谱法测定藜麦和绿豆芽等谷类产品中砷、镉、铅、锰、铜、锌和铁等7种微量重金属元素.以硝酸和双氧水消解样品,调谐优化仪器分析条件,锌、砷、铜、锰和铁等5种元素选用KED模式,铅和镉选用STD模式,以标准曲线法进行测定.结果显示:砷、镉、铅、锰、铜、锌和铁的线性回归方程分别为y=1.49×10^(2)x+0、y=3.06×10^(2)x+0、y=1.0267×10^(4)x+0、y=1.029×10^(3)x+0、y=1.088×10^(3)x+0、y=2.67×10^(2)x+0和y=3.4×10^(1)x+0;砷、镉、铅、锰和铜的线性范围均为0.10~800.0μg·L^(-1),锌的线性范围为5.00~300.0μg·L^(-1),铁的线性范围为5.00~800.0μg·L^(-1),相关系数均在0.9994~0.9996之间;检出限在6.8×10^(-6)~2.6×10^(-2)mg·kg^(-1)之间;相对标准偏差(n=6)在0.26%~13.1%之间;回收率在89.2%~107%之间.该方法满足同时对藜麦和绿豆芽等谷类产品中砷、镉、铅、锰、铜、锌和铁等7种元素的快速准确测定.

To establish an accurate and rapid determination method of trace heavy metal elements in cereal products,seven trace heavy metal elements(As,Cd,Pb,Mn,Cu,Zn,Fe)in cereal products,such as quinoa and mung bean sporouts,were determined by inductively coupled plasma mass spectrometry(ICP-MS).The samples were digested with nitric acid and hydrogen peroxide and the instrument analysis conditions were optimized.As,Mn,Cu,Zn,and Fe were determined by KED mode,while Pb and Cd were determined by STD mode.These seven elements were determined by the standard curve method.As shown by the results,the linear regression equations for As,Cd,Pb,Mn,Cu,Zn,and Fe were y=1.49×10^(2)x+0,y=3.06×10^(2)x+0,y=1.0267×10^(4)x+0,y=1.029×10^(3)x+0,y=1.088×10^(3)x+0,y=2.67×10^(2)x+0,y=3.4×10^(1)x+0,respectively;the linear range of As,Cd,Pb,Mn,and Cu was 0.10 to 800.0μg·L^(-1),that of Zn was 5.00 to 300.0μg·L^(-1),and that of Fe was 5.00 to 800.0μg·L^(-1);the correlation coefficients were between 0.9994 and 0.9996;the detection limits(3s/k)varied from 6.8×10^(-6)to 2.6×10^(-2)mg·kg^(-1);RSDs(n=6)ranged from 0.26%to 13.1%and the recoveries of samples were 89.2%~107%.This method is suitable for the accurate and rapid determination of As,Cd,Pb,Mn,Cu,Zn,and Fe in cereal products such as quinoa and mung bean spronts.