Thermospray-LC-MS analysis of various groups of polyphenols in tea

Abstract

An account is given of the application of thermospray LC-MS in the analysis of caffeoyl- andp-coumaroylquinic acids, theaflavins and thearubigins in black tea. All compounds, except for the thearubigens, could be detected as the pseudo-molecular ion [M+H]⁺. In addition to [M+H]⁺, other species such as adducts with sodium, ammonium and potassium, as well as solvent clusters were observed. The formation of those adducts depended upon on the structure of the compound. A fragmentation of chlorogenic acids occurred at elevated temperatures yielding the constituents of the molecules (caffeic,p-coumaric and quinic acids).