摘要
参考国家标准GB 5009.268-2016,采用微波消解-电感耦合等离子体质谱法(ICP-MS)对云南省3个不同产地的90个普洱生茶样品中铅、镉、镁、铝、钾、钙、锰、铁、铜、锌等10种矿质元素进行测定,采用聚类分析、主成分分析、线性判别分析探讨矿质元素溯源普洱生茶产地的可行性,筛选出有效的溯源指标。结果显示:10种矿质元素的质量浓度在1.0~100.0μg·L^(-1)内与其对应的响应值与内标响应值的比值呈线性关系,检出限(3s)为0.002~1μg·g^(-1);茶叶标准物质的测定值与认定值基本一致;并且不同产地普洱生茶中10种矿质元素的含量特征均不相同。从矿质元素含量的角度进行聚类分析,90个普洱生茶样品可以分为三大类,与实际分类结果相符。主成分分析得到两个主成分,其累计方差贡献率达80.381%。铅、镉、钙、锰、铁、铜、锌等7种元素被引入到产地判别模型中,利用模型对3个不同产地的普洱生茶样品进行初始检验和交叉检验,识别率均为100%;并利用该模型对来自保山的普洱生茶样品进行外部检验,识别率为0。
Referrig to national standard of GB 5009.268-2016,contents of 10mineral elements(Pb,Cd,Mg,Al,K,Ca,Mn,Fe,Cu,Zn)in 90Pu-erh raw tea samples from 3different regions of Yunnan province were determined by inductively coupled plasma mass spectrometry(ICP-MS)with microwave digestion.Cluster analysis,principle component analysis and linear discriminant analysis were carried out to examine the feasibility of mineral elements analysis in identifying the geographical origin of Pu-erh raw tea for screening out the effective indicators in Pu-erh raw tea origin assessment.As shown by the results,linear relationships between mass concentrations of 10mineral elements and response value ratios of analyted elements to internal standard elements were kept in the same range of 1.0-100.0μg·g^(-1),with detection limits(3s)in the range of 0.002-1μg·g^(-1),and the determined values on tea reference material were basically consistent with the confirmed value.Contents of 10mineral elements in Pu-erh tea from different regions were different.90Pu-erh tea samples were divided into 3 groups from the cluster analysis of mineral elements,which was basically consistent with the actual classification results.The samples were classified into two categories by principle component analysis,and the cumulative variance contribution rate was 80.381%.7elements of Pb,Cd,Ca,Mn,Fe,Cu,Zn were introduced into locality discrimination models.Base on the models,the initial inspection and cross inspection of samples from 3different origins were carried out,with the recognition rate of 100%.The models were used for external inspection of Pu-erh raw tea samples from Baoshan,and the recognition rate was 0.
作者
朱红玉
李云飞
张薇
张银
殷红
王英
ZHU Hongyu;LI Yunfei;ZHANG Wei;ZHANG Yin;YIN Hong;WANG Ying(Technology Center of Kunming Customs,Kunming650228,China)
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2022年第1期45-50,共6页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
原国家质量监督检验检疫总局科技计划项目(T2017-YNCIQ-0002)。
