Direct mass spectrometry approaches to characterize polyphenol composition of complex samples

Approaches based on direct ESI-TOF and MALDI-TOF mass spectrometry are proposed for profiling phenolic compositions of plant extracts and for determination of proanthocyanidin molecular weight distributions. Higher molecular weight proanthocyanidins are difficult to detect due to poor ionization and fragmentation, but this has been overcome by analyzing their protein complexes.