More than 20 flavonoids from different subgroups and nine commonly occurring phenolic acids were examined (analytical column Acquity UPLC BEH C18; 100 mm x 2.1 mm, 1.7 µm). The chromatographic separation was performed with binary mobile phase composed of methanol and 0.1% aqueous formic acid at convex gradient conditions.
The developed liquid chromatography method with UV detection at 280 nm was consequently extended with coupled mass spectrometric detection (MS/MS) using triple quadrupole mass analyzer. The method was after optimization of conditions for mass spectrometer applied to the analysis of tea extracts.