The main components of catechins in green tea include epicatechin (EC), epigallocatechin (EGC, hydroxy derivative of EC), epicatechin gallate (ECg, gallic acid ester of EC), and epigallocatechin gallate (EGCg, gallic acid ester of EGC).

Jasco examined the applicability of X-LC for ultra-high speed analysis of 7 components consisting of the above 4 catechins, catechin(C), catechin gallate(Cg), and caffeine.