The Study On Establishment And Application Of The Chromatographic Fingerprint Of Longjing Tea

Longjing tea is well known for its excellent quality in the world.It is a typical representative of famous tea and it plays an important role in tea industry of zhejiang province.Longjing tea is subjected to frauds with the addition of tea from other regions for great benefits,which disturbs the market order,so it’s necessary to find a efficient,rapid and accurate method to evaluate and monitor the quality of Longjing tea.In this work,HPLC fingerprint chromatogram of Longjing tea was established using the fingerprint technology of chinese medicine to discriminate the production regions.The results and conclusions were listed as follows:1.The study of quantitative analysis of Longjing tea quality by HPLC:Ingredients varied significantly different among three production regions.The relative standard deviation of gallic acid was larger relatively,and the relative standard deviation of alkaloids was smaller relatively among three regions.The content of gallic acid in XHLJ was higher than the others significantly,and the content of alkaloids and catechins in XHLJ was lower than the others significantly.The content of flavonol glycosides in YZLJ was higher than the others significantly.The content of amino acids in QTLJ lower than the others significantly.Ingredients varied significantly different among different cultivars.’Yingshuang’ had the highest alkaloid contents,and the content of catechins in ’Muhe’ was the highest.’Juhuachun’had the highest flavonol glycosides,and the content of amino acid in ’Wuniuzao’ was significantly higher than the others.2.The establishment of fingerprint chromatogram of Longjing:The characteristic fingerprint of Longjing tea with three production regions and seven cultivars were established,including gallic acids,alkaloids,catechins,flavonol glycosides and amino acids.In the fingerprint of XHLJ,33 characteristic peaks were identified and peak 13 was the unique peak.In the fingerprint of QTLJ,34 characteristic peaks were identified and peak 23 was the unique peak.In the fingerprint of YZLJ,35 characteristic peaks were identified and peak 6,peak 33 were the unique peaks.34,31,32,32,34,30,32 characteristic peaks were identified in ’Yingshuang’,’Wuniuzao’,’Longjing 43’,’Longjing Qunti’,’Muhe’,’Jiukeng’,’Juhuachun’ respectively.Peak 15 and peak 33 of ’Yingshuang’,peak 14 of ’Longjing 43’,peak 33 of ’Muhe’,peak 23 of ’Jiukeng’ and peak 15 of ’Juhuachun’ were the unique peaks in those cultivars respectively.3.Discriminant analysis of Longjing production regions based on HPLC fingerprint:Multiple fingerprint of Longjing tea was established.To contrast different pattern recognition classification methods,we found that that Discriminant Factor Analysis classified tea samples correctly,however the prediction result with DFA was imperfect.Multilayer Perceptron and Support Vector Machine had the ability to classify known sample and predict unknown sample effectively,and the prediction result of SVM was better than MLP.Those results revealed that it was possible to distinguish or verify the producing region of Longjng tea by combining the techniques of multiple chemical fingerprint with artificial intellegence discriminant methods.