Use of LC-Q-TOF-MS for Elucidating the Flavonoids Chemical Structures of Tea Leaves

Flavonoids are important secondary metabolites in tea plants, which contribute to the formation of high-quality tea leaves. Their structural variability and similitude increase the difficulty of compound identification. The powerful tool of LC-Q-TOF-MS, combining the separation capabilities of liquid chromatography (LC) with the structural analysis potential of quadrupole time-of-flight mass spectrometry (Q-TOF-MS), provides high selectivity and sensitivity, making it ideal for detecting flavonoids. In this chapter, we present a protocol for the comprehensive identification of flavonoids compounds in tea leaves based on LC-Q-TOF-MS/MS, which concludes the basic principles of LC-Q-TOF-MS, a data processing methodology, relative software operational essentials.