基于稀土元素含量江西茶叶产地特征分析与溯源判别

Origin Characteristics and Traceability Discrimination of Jiangxi Tea based on Rare Earth Element Contents

为了解江西茶叶中稀土元素的残留状况,减少稀土污染,提高茶叶品质。研究建立江西茶叶产地判别技术,为保护地理标志产品、追溯原产地来源提供理论依据。本研究采集江西省遂川县、庐山县和婺源县共3个产地的138批次茶叶样品,利用电感耦合等离子串联质谱仪法(ICP-MS/MS)测定茶叶中15种稀土元素含量,并对数据进行主成分分析和判别分析,建立产地判别模型。结果表明,3个产地138批次茶叶的稀土氧化物总量在0.44~1.57 mg·kg^(-1)之间,均未超出国家标准GB 2762-2012限量。经过主成分分析,从15种稀土元素可提取3个主成分,代表了总指标90.66%的信息;利用判别典型函数分析,回代检验100%正确判别,交叉检验的正确判别率为99.3%。此方法证明稀土元素技术可用于江西茶叶的产地溯源,为今后江西各种知名茶叶品牌的原产地保护提供鉴定基础。

To investigate the rare earth elements residues in teas from Jiangxi Province in order to provide suggestions on reducing rare earth elements(REEs)contamination,and to improve the quality of tea.A method for geographical origin discrimination of tea from Jiangxi Province was established to provide technical support for the protection of geographical indication products and for tracing the geographic origin of agricultural products.One hundred and thirty-eight samples of tea were collected from three producing areas:The counties of Suichuan,Lushan and Wuyuan in this study.Inductively coupled plasma tandem mass spectrometry(ICP-MS/MS)was used to determine the contents of 15 rare earth elements in tea.Principal component analysis(PCA)and fisher linear discriminant analysis(FLD)were applied to differentiate the tea geographical origin.The results showed that the total amount of rare earth oxides in the teas were 0.44~1.57 mg·kg^(-1) and did not exceed the national limit standard of rare earth elements in tea(GB 2762-2012).After principal component analysis,three principal components were extracted from 15 rare earth elements(REEs),representing 90.66% of the total index information.Fisher discriminant analysis showed that the correct discriminant rates of back generation test and cross test were 100% and 99.3%.It is proved that rare earth elements(REEs)tracing technology can be used in tea origin discrimination and provide the identification basis for the protection of the origin of Jiangxi famous tea brands in the future.