Observation of apigenin anionic clusters in the gas phase

The ubiquity and favorable medicinal properties of flavonoids make essentia l the determination of flavonoid levels in various matrices. While developi ng a liquid chromatography/tandem mass spectrometry method for the analysis of the flavonoid, apigenin, anionic oligomers and nitrate- and chloride-bo und clusters of this compound were observed. Tandem mass spectrometry of th ese oligomers and cluster ions showed the cleavage of apigenin molecules fr om the precursor. The observation of these cluster ions shows the possibili ty of post-column derivatization techniques to enhance specificity in analy sis. Copyright (C) 2000 John Wiley & Sons, Ltd.