微波等离子体原子发射光谱测定啤酒中的常量和微量金属元素

Determination of Major and Trace Metal Elements in Beer by Microwave Plasma-Atomic Emission Spectroscopy

建立微波等离子体原子发射光谱(microwave plasma-atomic emission spectroscopy,MP-AES)测定啤酒中4种常量金属元素(Na、Mg、K、Ca)和10种微量金属元素(Al、Mn、Fe、Ni、Cu、Zn、Sr、Cd、Ba、Pb)的分析方法。在密闭的消解罐内采用质量分数65%HNO3溶液对啤酒样品进行微波消解,选择分析元素的波长并结合快速线性干扰校正技术校正光谱干扰,通过加入内标元素校正基体效应,采用电感耦合等离子体质谱(inductively coupled plasma-mass spectrometry,ICP-MS)法对相同的样品溶液进行分析比较验证方法的准确性。在优化条件下,分析元素的检出限在0.13~230μg/L之间,加标回收率为95.6%~104%,相对标准偏差为1.8%~4.0%。采用MP-AES成功测定啤酒样品中的常量和微量金属元素,并与ICP-MS的测定结果基本一致。方法具有简单快速、稳定性好、运行成本低、准确性好的特点,适合于啤酒中多种金属元素的高通量分析。

An analytical method was established for the determination of four major metal elements(Na,Mg,K,and Ca)and ten trace metal elements(Al,Mn,Fe,Ni,Cu,Zn,Sr,Cd,Ba,and Pb)in beer by microwave plasma-atomic emission spectroscopy(MP-AES).The samples were microwave digested using HNO3 in closed digestion vessels.The spectral interferences were corrected by selecting a suitable wavelength as well as using fast linear interference correction(FLIC).The matrix effect was corrected by using internal standard elements.Inductively coupled plasma-mass spectrometry(ICP-MS)was used to analyze the same sample solution to demonstrate the accuracy of the method.Under the optimized conditions,the limits of detection(LODs)for the analytes were in the range of 0.13–230μg/L.The spiked recoveries ranged from 95.6%to 104%with relative standard deviations(RSDs)of 1.8%–4.0%.All the major and trace metal elements were successfully determined in beer samples by the MP-AES method and the results obtained were identical to those obtained by ICP-MS.The method has the characteristics of simple and fast operation,good stability,low running cost and good accuracy,and is suitable for high throughput analysis of multiple metal elements in beer.