was developed and validated for the analysis of major catechins, proanthocyanidin ( procyanidin B2) and caffeine in 25 different natural complex matrices containing Camellia sinensis L . and/or grape seed extracts , two popular plant extracts that have been widely used as
natural antioxidants in various food and beverage applications . Using an isocratic elution system, separation of all compounds was achieved with in 12 min.