ICP-MS法测定高钙食品中铅、镉、砷、铜的研究

目的：研究溶液中高含量钙的基体效应及降低基体干扰的方法,建立ICP-MS测定高钙食品中铅、镉、砷、铜含量的分析方法。方法：样品采用微波消解,通过研究功率和载气流速在不同钙基体含量时对铅砷铜镉测定的影响,结合调谐液优化仪器工作参数,选择合适的内标元素对钙基体干扰进行校正。结果：高钙食品中钙基体含量不超过0.1%,在90 min内连续进样引起的基体干扰基本上得到克服。各元素加标回收率均在86%-99%,标准偏差均低于3.5%。结论：方法准确可靠,适用于高钙食品中铅、镉、砷、铜含量的同时测定。

Study of testing Pb,Cd,As,Cu in high calcium food by inductively coupled plasma-mass spectrometry

Objective:To study the matrix effects of high calcium and the means of reducing matrix disturbs in solution to establish the method of testing Pb,Cd,As,Cu in high calcium food by inductively coupled plasma-mass spectrometry.Methods:The sample was digested by microwave technique.The instrumental parameters were optimized by studying the influence of RF power and carrier gas flow rate on the determination in different concentrations of calcium matrix and combining tuning solution.The interference of calcium matrix was corrected by selecting appropriate internal standardization element.Results:When the concentration of calcium was not over 0.1% in solution of high calcium food,the interference of matrix could be eliminated basically within sampling continuously for 90 mins.Spike recovery of each element was within 86%~99%,and their relative standard deviations were all lower than 3.5%.Conclusion:This accurate and reliable method is suitable for the simultaneous measurement of Pb,Cd,As and Cu in high calcium food.