Liquid chromatography/tandem mass spectrometry studies of the phenolic compounds in honey

An improved and simplified analytical method which offers rapid, accurate determination and identification of phenolic compounds in honey samples is reported. The honey samples were diluted by acidified water (pH 2), and analyzed by HPLC–ESI-MS/MS. Simultaneously determination of phenolic acids and flavonoids was carried out by a liquid chromatography–mass spectrometry. Comparison between atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) was performed by analysis of standards. Fragmentation of analytes for subsequent selective Multiple Reaction Monitoring (MRM) analysis was investigated in negative mode. Sample preparation without separation of sugars and clean-up procedure, followed by fast chromatographic separation using a narrow-bore column C18 (50 mm × 2.1 mm, 3 μm) allowed the analysis to be completed in a short run time. LODs were ranged between 1 and 15 ng L⁻¹ for p-coumaric acid and naringenin, respectively. The method was applied for determination of phenolic acids and flavonoids in honey samples from different botanical origin.