ICP-MS法测定菊花茶中砷镉铜铅锌

ICP-MS DETERMINATION OF As Cd Cu Pb and Zn IN CHRYSANTHENUM TEA

采用电感耦合等离子体质谱(ICP-MS)法,对菊花茶中微量元素砷、铅、镉、铜、锌进行了分析.用HNO3-H2O2消解样品,通过在线加入内标校正基体效应和接口效应,通过修正方程校正质量数干扰.测定元素校正曲线的相关系数都在0.999 5以上,各元素的检出限在0.020～0.14 μg·L-1,样品分析结果的相对标准偏差为1.5%～4.3%(n=10),加标回收率在93.9%～101.6%之间.用此方法测定茶叶标准物质GBW 07605,结果与标准值基本一致.

ICP-MS was applied to the simultaneous determination of 5 elements （As, Cd, Cu, Pb, Zn） of micro-amounts in chrysanthenum tea, and the details of treatment of sample and working parameters of the instrument were described. The matrix effect and interface effect were corrected by the in-line addition of internal standards, and the mass number interference was amended by applying the correction equation recommended in EPA 200. 8. Satisfactory linearity of working curves of the 5 elements was obtained, giving all their correlation coefficients over 0. 999 5. Detection limits of these element were found in the range from 0.020-0. 14 μg · L^-1. RSD＇s （n=10） in the range of 1.5%-4. 3% and recoveries in the range from 93.9%-101.6% were obtained in its application to the analysis of tea samples. The results obtained in the analysis of a standard reference material of tea （GBW 07605） by this method were in consistency with the certified values given in the certificate.