CAPILLARY LIQUID-CHROMATOGRAPHY ELECTROSPRAY MASS-SPECTROMETRY FOR THE SEPARATION AND DETECTION OF CATECHINS IN GREEN TEA AND HUMAN PLASMA

The separation and detection of biologically active green tea catechin s has been accomplished using capillary liquid chromatography/electros pray mass spectrometry (cLC/ESI-MS), Microscale determination (similar to 20 ng) of all six catechins in a green tea infusion, and the most extensively studied catechin, (-)epigallocatechin gallate (EGCG), in h uman plasma is demonstrated by cLC/ESI-MS with selected ion monitoring of protonated molecular ions. The overall quality of the analysis is shown to be dependent on the use of a capillary column with a deactiva ted, monomeric C-18 stationary phase, The high chromatographic separat ion efficiency of this packed-capillary column, combined with the high sensitivity and selectivity afforded by the mass spectrometer as dete ctor, provide a reliable approach to the analysis of picomolar quantit ies of these interesting compounds in complex matrices. (C) 1997 John Wiley & Sons, Ltd.