Hai-Bo Pan, Dan Zhang, Bo Li, Yuan-Yuan Wu, You-Ying Tu; A Rapid UPLC Method for Simultaneous Analysis of Caffeine and 13 Index Polyphenols in Black Tea. J Chromatogr Sci 2017 1-6. doi: 10.1093/chromsci/bmw197
A fast ultrahigh performance liquid chromatography (UPLC) method has been developed for simultaneous analysis of caffeine and 13 index polyphenols-gallic acid, 8 primary catechins and 4 primary theaflavins in black tea. The method was evaluated in terms of linearity, precision, accuracy and recovery. The lower limits of detection and quantification were in the range of 0.05–0.91 and 0.15–3.00 mg/L, respectively. Satisfactory linearity with correlation coefficient (R2 > 0.9992), interday and intraday precision with the relative standard deviations (<2.94% and <5.06%, respectively), interday and intraday accuracy with relative errors (REs, −5.34% < REs < 4.36% and −5.36% < REs < 7.07%, respectively) and recovery (95.81–104.48%) were achieved for all target compounds. The UPLC method was applied for the analysis of the 14 compounds in 6 black tea samples.