Determination of catechins and caffeine in tea polyphenols / 中成药

ABSTRACT

Objective: To develop a HPLC method for simultaneous determination of catechins (EGC、DC、EGCG、EC、GCG、ECG) and caffeine in tea polyphenols and to quantify seven ingredients in twenty nine batches of tea polyphenols samples from thirteen producers. Methods: The study was achieved using a C 18 column with a methanol water 0.1% formic acid gradient elution system. Results: The peak resolutions of seven ingredients in mixed standards were all above 2; The resolutions in samples were all above 1.5 except EGCG; The average recoveries were 98.56%～100.14%. Conclusion: This method is accurate, stable, reproducible and suitable for quality control of tea polyphenols; the variations of contents are obvious among tea polyphenols samples from different even the same producers.