title: A Rapid UPLC Method for Simultaneous Analysis of Caffeine and 13 Index Polyphenols in Black Tea.
abstract: 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.
authors.affiliation: Tea Research Institute of Zhejiang University, Hangzhou 310058, Zhejiang Province, PR China.
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Pan
authors.affiliation: Tea Research Institute of Zhejiang University, Hangzhou 310058, Zhejiang Province, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Tea Research Institute of Zhejiang University, Hangzhou 310058, Zhejiang Province, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.affiliation: Tea Research Institute of Zhejiang University, Hangzhou 310058, Zhejiang Province, PR China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Wu
authors.affiliation: Tea Research Institute of Zhejiang University, Hangzhou 310058, Zhejiang Province, PR China.
authors.forename: You-Ying
authors.initials: YY
authors.lastname: Tu
mesh_terms: D002110:Caffeine / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D057230:Limit of Detection; D016014:Linear Models; D059808:Polyphenols / Q000032:analysis*; D015203:Reproducibility of Results; D013662:Tea / Q000737:chemistry*
chemical_list: D059808:Polyphenols; D013662:Tea; D002110:Caffeine