Confirmation of phenolic acids and flavonoids in honeys by UPLC-MS

Certain phenolic acids and flavonoids are described in the literature as marker substances for several unifloral honeys. As not all authors utilised the same methods for extraction and determination, there are remarkable discrepancies in the published data concerning these substances. Ethyl acetate extracts which, aside from phenolic acids, also contain flavonoids were analysed by Ultra Performance Liquid Chromatography-Quadrupole/Time of flight-mass spectrometry (UPLC-Q/TOF-MS). First, the mass spectra of 37 phenolic acids and flavonoids described in the literature were recorded. Consequently, sunflower honeys, lime honeys, clover honeys, rape honeys, and honeydew honeys were analysed in regard to these substances. By employing the ChromaLynx$^{\rm TM}$ software, 34 of the 37 substances were identified quickly and clearly. By combining the retention time and the accurate molecular mass, it was even possible to identify several compounds which cannot be detected by diode array detection