Abstract:

An analytical method for the determination of lincosamide antibiotic residues in honey was developed. In the procedure a solid-phase extraction for the isolation of lincomycin and clindamycin from diluted honey samples was employed. The residues of lincomycin and clindamycin were subsequently analyzed by reversed-phase high performance liquid chromatography (RP-HPLC) coupled with electrospray tandem mass spectrometry. Mass spectral acquisition was applied with selective reaction monitoring of two diagnostic transition reactions. The qualitative analysis was based on the retention time, the precursor ion and two product ions, and the quantitation was carried out with intension of the characteristic ion m/z 126. The linear ranges were from 1.0 μg/L to 200 μg/L for lincomycin and clindamycin and the correlation coefficients (r2) were all greater than 0.996. The average recoveries for lincomycin and clindamycin ranged from 80% to 110% in replicate sets of honey samples spiked with the drug concentrations of 1.0, 5.0 and 20.0 μg/kg, and the relative standard deviations (RSDs) were less than 8% for intra-day and 15% for inter-day determinations. The method detection limit and quantitation limit were 0.1 μg/kg and 0.5 μg/kg, respectively. The method is simple and suitable for routine analysis.

Key words: clindamycin, electrospray tandem mass spectrometry （ESI-MS/MS), honey , lincomycin, lincosamide antibiotics, high performance liquid chromatography (HPLC)