title: Capillary liquid chromatography/electrospray mass spectrometry for the separation and detection of catechins in green tea and human plasma.
abstract: The separation and detection of biologically active green tea catechins has been accomplished using capillary liquid chromatography/electrospray mass spectrometry (cLC/ESI-MS). Microscale determination (approximately 20 ng) of all six catechins in a green tea infusion, and the most extensively studied catechin, (-)epigallocatechin gallate (EGCG), in human 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 deactivated, monomeric C18 stationary phase. The high chromatographic separation efficiency of this packed-capillary column, combined with the high sensitivity and selectivity afforded by the mass spectrometer as detector, provide a reliable approach to the analysis of picomolar quantities of these interesting compounds in complex matrices.
authors.affiliation: Analytical Chemistry Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Dalluge
authors.forename: B C
authors.initials: BC
authors.lastname: Nelson
authors.forename: J B
authors.initials: JB
authors.lastname: Thomas
authors.forename: M J
authors.initials: MJ
authors.lastname: Welch
authors.forename: L C
authors.initials: LC
authors.lastname: Sander
mesh_terms: D002392:Catechin / Q000032:analysis / Q000097:blood* / Q000302:isolation & purification*; D002853:Chromatography, Liquid; D006801:Humans; D013058:Mass Spectrometry; D013662:Tea / Q000737:chemistry*
chemical_list: D013662:Tea; D002392:Catechin