Thermospray-LC-MS analysis of various groups of polyphenols in tea. II: Chlorogenic acids, theaflavins and thearubigins.

An account is given of the application of thermospray LC-MS in the analysis of caffeoyl- and p-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).