The health benefits associated with tea con-sumption have resulted in the wide inclusion of green tea extracts in botanical dietary supplements, which are widely consumed as adjuvants for complementary and alternative medicines. Tea contains polyphenols such as catechins or flavan-3-ols including (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)- epicatechin gallate (ECG), and (-)-epigallocate-chin gallate (EGCG), as well as the alkaloid, caffeine. The contents of catechins and caffeine in green tea are con-sidered as a standard of quality evaluation of green tea. Therefor, the purpose of this study was to investigate the most suitable HPLC condition for simultaneous determina-tion of catechins and caffeine in green tea extracts. The efficient HPLC analytical condition of catechins and caf-feine contained green tea extracts was developed. The gra-dient elution employed a 250 mm × 4.6 mm i.d. YMC-pak ODS-AM 303 column. The gradient system was used two mobile phases. A gradient elution was performed with mo-bile phase A, consisting of 0.1% aqueous phosphoric acid, and mobile phase B, comprising 100% MeOH, and deli-vered at a flow rate of 1 mL/min as follows: 0~25 min, 80% A; 26~50 min, 80~70% A; 51 min, 80% A. 51~55 min, 80% A. The UV detection wavelength was set at 280 nm. The limit of detection (LOD) for catechins and caffeine stan-dards were under 50 ng/mL.
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