利用ICP-MS/MS测定白酒中无机元素的主成分分析及聚类分析

建立电感耦合等离子体串联质谱(inductively coupled plasma tandem mass spectrometry,ICP-MS/MS)法测定18种白酒中14种无机元素的含量,研究白酒中无机元素含量的分布规律及其与白酒品种之间的关系。白酒样品经简单稀释后直接进样,采用ICP-MS/MS测定其中Mg、Al、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Se、Sr、Ba、Pb的含量,在MS/MS模式下,分别选择O2和NH3/He为反应气,消除质谱干扰,将分析结果进行标准化处理后利用SPSS主成分分析和聚类分析对无机元素分布进行评价。各元素的检出限为1.34~25.8 ng/L,加标回收率为93.0%~105%,相对标准偏差(RSD)≤3.84%,方法的检出限低、准确度好、稳定性和精密度高。主成分分析结果显示,积累方差的80.003%来自前5个主成分,18种白酒的特征元素为Al、Fe、Ba;聚类分析将18种白酒划分为4类,可实现白酒品种的初步判别,不同产地白酒中无机元素的含量具有明显差异性。

Principal component analysis and cluster analysis of inorganic elements in Baijiu using inductively coupled plasma tandem mass spectrometry

An analytical method for the determination of 14 inorganic elements in 18 Baijiu was developed by inductively coupled plasma tandem mass spectrometry(ICP-MS/MS).The distribution of inorganic elements in Baijiu and the relationship between inorganic elements and different kinds of Baijiu were investigated.After dilution,the Baijiu samples were directly injected into ICP-MS/MS for the determination the contents of Mg,Al,Cr,Mn,Fe,Co,Ni,Cu,Zn,As,Se,Sr,Ba and Pb.In the MS/MS mode,O2 and NH3/He were selected as reaction gases to remove spectral interference.The SPSS principal component analysis and cluster analysis were conducted to evaluate the distribution of inorganic elements after data standardizing.The detection limits for these analytes range from 1.34 to 25.8 ng/L.The recoveries of the samples were between 93.0% and 105%,and the relative standard deviation(RSD)was≤3.84%.This method has low detection limit,high accuracy,stability and precision.The results of principal component analysis showed that 80.003% of the cumulative variances came from the first five principal components.Al,Fe and Ba may be the characteristic elements in 18 Baijiu.The cluster analysis showed that 18 Baijiu samples formed into four clusters,which could be used for the preliminary discrimination of different kinds of Baijiu.Moreover,the content of inorganic elements from different producing areas in China also showed significant differences,which could be used as an indicator for the discrimination of different Baijiu.