Novel HPLC Method to Evaluate the Quality and Identify the Origins of Longjing Green Tea

Abstract

A novel model of evaluating the quality and identifying the origins of Longjing green tea was established for the first time in this study. The analysis procedures in the model included the structure speculation of the major compounds and the identification of the bioactive components, the establishment of the fingerprint, the multiple analysis of the fingerprint, and the quantitative determination of the bioactive components. All the analysis procedures were conducted on an HPLC coupled with diode array detection (DAD) and an ion-trap coupled with a time-of-flight mass spectrometry (IT-TOF-MS). In this study, 13 batches of Longjing green tea from five traditional production sites and a new production site in Hangzhou, China were selected to establish the model. The result showed that using the model, the difference between Longjing green tea from the traditional and the new production sites was revealed successfully. It indicated that the model could be successfully applied to evaluate the quality and identify the origin of unknown Longjing green tea.

Keywords:

• Fingerprint
• LC-IT-TOF-MS
• Longjing green tea
• Origin identification
• Quantitative analysis

Acknowledgments

This work was financially supported by the National Key Scientific Project for New Drug Discovery and Development (No.2009ZX09301-012).

Notes

^a 1st grade.

^b 2nd grade.

^c super-grade.

^a LOD refers to the limits of detection.

^b LOQ refers to the limits of quantification.

^c RSD (%) = (S.D./mean) × 100.

^d Recovery = 100 × (amount found-original amount)/amount spiked; the data presented as the average of three concentrations.

^e The RSD of which is stated in “d.”.

^a Sample number as listed in Table 1.

^b The similarity was calculated by Similarity Analysis, each fingerprint (from Fig. 4) was compared the consensus chromatogram “R.”.

^a Sample number as listed in Table 1.

^b Values in mg · g⁻¹of Longjing green tea; Content = mean±S.D., n = 3. (R.S.D. < 5.0%).

^c Variation (%) = SD/mean × 100.