Separation of tea polyphenols using micellar electrokinetic chromatography with diode array detection

Abstract

Micellar electrokinetic capillary chromatography has been investigated for its potential in the analysis of polyphenols in tea. Conditions have been optimised by systematically examining the effect of inorganic buffer, micelle, borate and organic solvent concentration. These conditions have then been used to analyse a range of tea types, including an instant green, Darjeeling and black Assam tea. The more fully fermented Assam proved too complex to analyse per se and was split into three fractions prior to electrophoresis. Most of the major classes of tea components were observed and identified using a diode array detector, but the theaflavins were either adsorbed or degraded by the capillary wall.