Simultaneous analysis of individual catechins and caffeine in green tea

A simple and fast high performance liquid chromatography analysis method for eight tea catechins and caffeine using an ODS column and a water-acetonitrile-phosphoric acid mobile phase system was developed. The catechins, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate, catechin, catechin gallate, gallocatechin and gallocatechin gallate, and caffeine were separated by an acetonitrile gradient within 20 min. The detection limit of this method was approximately 0.2 ng for all nine compounds and the quantitation curves were linear between 2 ng to 2 mu g. Some Japanese green tea samples were analyzed using this method. No extraneous peaks interfered with the analysis and the detection limit of each compound was less than 0.02% of the dry weight of the tea.