A RP-HPLC method for the determination of tea catechins

An HPLC method with gradient elution for the quantification of catechins ((−)-epigallocatechin (EGC), (+)-catechin (C), (−)-epicatechin (EC), (−)-epigallocatechingallate (EGCg) and (−)-epicatechingallate (ECg)) in tea was developed. The method was used to determine catechins in black tea, green tea and oolong tea. Sample preparation was simple because only filtration and adjustment of pH was required. The levels of catechins in different teas...