Study Of Anxi-Tieguanyin Tea Identification Method Based On Feature Analysis Of Rare Earth Elements

Tea is the important characteristics of agricultural products with obvious regional feature and quality characteristics in our country. Analytical methods and traceability technique are very important for the protection of geographical origin and authenticity of tea. Tieguanyinhas the superior quality and unique style, but different regional ecological environment quality of Tieguanyin exist certain differences due to the influence of different ecological environment. The experiment established the analysis of 16 kinds of rare earth elements (REE) in tea leaves by using ICP-MS, the instrument condition was optimized, and experiment was making through the determination of standard reference materials and standard addition test, and it could get satisfactory results. The advantages of method is fast and accurate, high sensitivity, low detection limit, wide linear range, etc.(1) The two pretreatment methods of microwave digest and dry ashing were compared in tea. The results showed that the two methods exhibited no significant different effects on the evaluation of 16 kinds of rare earth elements, so the dry ashing method was suitable for the determination of rare earth elements in tea.(2) The contents of rare earth elements in tea have a big difference due to the producing area, climate conditions, geographical conditions, cultivation condition and parts of tea shoots. In this study, the classification of chemical pattern recognition was discriminated in the purpose of the Tieguanyin tea origin judgment.16 rare earth elements in Tieguanyin tea samples from different origins were determined by Inductively Coupled Plasma-Mass sepectrometry(ICP-MS), and the data of rare earth elements from different Tieguanyin tea were screened and analyzed using Chemical metrology software of orthogonal partial least squares-discriminant analysis(OPLS-DA) and bidirectional orthogonal partial least squares-discriminant analysis(O2PLS-DA). Therefore, the establishment of the origin identification model for Anxi and Un-Anxi Tieguanyin could identify the origin of Anxi-Tieguanyin tea rapidly and accurately. Content of rare earth elements have their own characteristics in different regional sources in tea which can be used to the discriminant analysis for the original birthplace of tea, however it has its limitations.(3) The feasibility of geographical origin trace for Anxi-Tieguanyin based on the characteristics of REE was discussed in the paper. In order to confirming the tea producing regions systematically, pattern recognition techniques were used in combination with characteristic components of tea such as REE, isotopes and amino acid. It could bring a more effective identification and protection for the special geographical indication products. The origin traceability model of Anxi-tieguanyin tea by model recognition technology will provide a technical support for Anxi-tieguanyin tea traceability, promote the healthy development for tea industry, and give a hand to tea origin protection in china.