Analysis of some selected catechins and caffeine in green tea by high performance liquid chromatography

► Low cost and precise HPLC method for determination of catechins and caffeine in GTs. ► Concentrations followed the order: EGCG > EGC > ECG > EC > C > caffeine. ► Significant release of EGCG and EGC on increasing infusion time from 5 to 30 min. ► No correlations between price and catechins and caffeine content in tea infusion. ► Geographic origins and tea GTs processing influenced catechins content in leaves.