Simultaneous determination of multi-veterinary drug residues in honey by solid phase extraction-high performance liquid chromatography-tandem mass spectrometry

A method of solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) for simultaneous determination of 54 drug residues (sulfonamides, nitroimidazoles, quinolones, macrolides, lincosamides and praziquantel) in honey was developed. The honey samples were diluted by phosphate buffer solution (pH 8) followed by a further cleanup procedure with an Oasis (HLB) SPE column. The detection was carried out by LC-MS/MS, using positive-ion electrospray ionization in multiple reaction monitoring (MRM) mode, with one precursor/two product ion transitions for each compound. Isotope dilution internal standard method or external standard method was used to determine the residue contents with a good linear relationship (r > 0.992). The limits of quantification (LOQs, S/N > 10) were 1.0 mu g/kg for sulfonamides and nitroimidazoles, 2.0 mu g/kg for quinolones and lincosamides, 3.0 mu g/kg for macrolides, and 0.3 mu g/kg for praziquantel. The recovery ranges were from 32.6% to 114% with the relative standard deviations (RSDs) between 1.3% and 28.9%. As a screening method, the developed procedure is suitable for the determination and confirmation of the drug residues in honey samples.