电感耦合等离子体质谱法直接测定酱油中铅

Direct determination of lead in soybean sauce by using inductively coupled plasma mass spectrometry

目的：建立电感耦合等离子体质谱（ICP—MS）法直接测定酱油中铅的方法。方法：酱油经适当稀释后直接进样测定，外标法绘制工作曲线、在线内标校准基体效应及信号漂移。结果：相对标准偏差〈3．0％，加标回收率95．8％～104．3％，用该方法对CNAS能力验证酱油样品进行了测定，测定结果令人满意。结论：该方法样品前处理简单，方法准确、灵敏、快速，检出限低，精密度好。

Objective：To develop a method for the determination of lead in soybeam sauce by using ICP - MS. Methods：The sample was 1：10 diluted with 1% HNO3 and then introduced into ICP -MS. External calibration was applied for making calibration curve and on - line internal calibrtion for eliminating matrix effect and signal drift, respectively. Results：The relative standard deviations （RSD） was 〈 3.0% and the recovery percentages were between 94. 2% - 104. 3%. The approach was validated using soybeam sauce reference sample during CNAS test, the analytical value matched very well the certified value. Conclusion：This is a simple, sensitive and accurate method to determine lead in soybeam sauce.