微波消解-ICP-MS法测定水生蔬菜中硼、铬、锰、镍、砷、硒、镉、铅含量

Determination of B,Cr,Mn,Ni,As,Se,Cd and Pb in aquatic vegetables by microwave digestion-ICP-MS

目的建立微波消解-电感耦合等离子体质谱(ICP-MS)法测定水生蔬菜中硼、铬、锰、镍、砷、硒、镉、铅含量的分析方法。方法以硝酸为消解液,样品经微波消解处理后稀释定容,在已优化好的ICP-MS工作条件下,以^(6)Li、^(45)Sc、^(72)Ge、^(115)In、^(209)Bi作为内标元素校正基体干扰和漂移,直接用ICP-MS进行分析水生蔬菜中8种金属元素,通过标准曲线分析元素含量。结果元素硼、铬、锰、镍、砷、硒、镉、铅在范围内呈良好的线性关系,标准曲线相关系数均≥0.9996,其检出限在0.10μg/kg~0.46μg/kg,相对标准偏差(RSD)≤3.29%;各元素的平均加标回收率为90.8%~109.0%;水生蔬菜中8种金属元素的含量均在允许限度范围内。结论本方法快速、准确、灵敏度高、有良好的重现性及稳定性,适用于水生蔬菜中硼、铬、镍、锰、砷、硒、镉、铅含量的测定。

Objective To establish a method for the determinationof B,Cr,Mn,Ni,As,Se,Cd,and Pb in aquatic vegeta-bles by microwave digestion-inductively coupled plasma-mass spectrometry(ICP-MS)method.Methods The sample was digested by microwave-asisted digetion with nitrie acid and then analyzed by ICP-MS with^(6)Li,^(45)Sc,^(72)Ge,^(115)In,^(209)Bi as intemal standards to calibrate the matrix interference and drift,and the contents of 8 kinds of metal element in aquatic vegela-bles were analyzed by standard curve calculation.Results B,Cr,Mn,Ni,As,Se,Cd,and Pb all showed good linearity within the detection limit of the method.The correlation cofficients(r)of the standard curve were≥0.9996,the detection limit was0.10μg/kg-0.46 ug/kg,and the relative standard deviation(RSD)was≤3.29%.The average recovery of each element was within 90.8%-109.0%。The contents of eight metal elements in aquatic vegetables were all within the allowable limits.Conclusion The microwave digestion-ICP-MS method was rapid and accurate with high sensitivity,good reproduc-ibility and stability It is suitable for the determinationof B,Cr,Mn,Ni,As,Se,Cd,and Pb in aquatic vegetables.