Trace analysis of fumagillin in honey by liquid chromatography-diode array–electrospray ionization mass spectrometry

In this work a new liquid chromatography with diode array detection and electrospray ionization mass spectrometry (LC-DAD–ESI-MS) method has been developed for the determination of fumagillin residues in honey. This procedure involves a solid-phase extraction on polymeric cartridges for the isolation of fumagillin from diluted honey. Chromatographic separation of fumagillin was performed in isocratic mode, on a C18 column (150 mm × 4.60 mm i.d., 5 μm), the mobile phase consisted of a mixture of ammonium formate 20 mM in water and acetonitrile (61/39, v/v), at 35 °C and the flow rate was set at 1.0 mL/min. Average analyte recoveries, influenced by the botanical origin were from 88 to 96% in replica sets of fortified honey samples. The detection limits of the LC-DAD–ESI-MS method were between 24 and 1 μg/kg for clear honeys (rosemary) and between 45 and 4 μg/kg for dark honeys (heather). The developed method has been applied to the analysis of fumagillin residues in honey samples collected from veterinary treated beehives, infected by Nosema ceranae and fed with the technical product at different doses.