微波等离子体光谱法同时测定食盐中多种微量元素

Simultaneous Determination of Multiple Trace Elements in Salt by Microwave Plasma Spectrometry

该研究采用4200型微波等离子体原子发射光谱仪(MP-AES)同时测定日常生活中常见的几种营养强化盐中Ca、Mg、Fe、Zn、Se、Na、K 7种有益元素的含量,系统地探究了介质的种类、酸的浓度、样品的前处理方式对测量结果准确度和精密度的影响。分析结果表明,7种元素在0~10 mg/L的线性范围内相关系数均≥0.994,方法检出限(LOD)的范围为0.3238~32.56μg/L,各个条件下的线性范围宽度均可达到3个数量级以上,样品加标回收率在96.6%~110.3%之间。该方法准确快速、成本低、安全性高,适用于食盐中众多元素的同时检测分析,对食盐的营养评估、提高市民对食盐的正确选择意识具有重要的指导意义。

In this study,the content of seven beneficial elements such as Ca,Mg,Fe,Zn,Se,Na and K in several kinds of nutrition-enhanced salt commonly used in daily life is determined by 4200 microwave plasma spectrometer(MP-AES).The effects of the type of media,the concentration of acid and the pretreatment modes of samples on the accuracy and precision of the detection results are systematically investigated.The results show that the correlation coefficients of the seven elements in the linear range of 0~10 mg/L are≥0.994,the LOD range is 0.3238~32.56μg/L,the linear range width under each condition could reach more than three orders of magnitude,and the recoveries of the samples are between 96.6%and 110.3%.The method is fast,with low cost and high safety,is suitable for simultaneous detection and analysis of many elements in salt,it is of great guiding significance to evaluate the nutrition of salt and raise the citizens'correct choice awareness of salt.