Development and validation of a solid-phase extraction method coupled with LC-MS/MS for the simultaneous...

The present study was carried out to determine 16 antibiotics belonging to seven different groups (tetracyclines, sulfonamides, penicillins, fluoroquinolones, macrolides, lincosamides and trimethoprims) in duck meat. A solid-phase extraction method based on Oasis HLB cartridges coupled with liquid chromatography-electrospray ionization tandem mass spectrometry was developed. Solutions of 0.1 m ethylenediaminetetraacetic acid disodium salt and 2% trifluoroacetic acid were used for the preliminary extraction of the target antibiotics from duck meat and n-hexane was used for purification prior to solid-phase extraction. Mobile phases composed of 0.1% trifluoroacetic acid in distilled water (solvent A) and 0.1% trifluoroacetic acid in methanol (solvent B), combined with a reversed-phase C₁₈ analytical column, provided the optimal separation and signal intensity. The linearity of the method was assessed using six concentrations (5, 10, 20, 30, 40, and 50 μg/kg), and the recoveries, which were calculated at three spiking concentrations (5, 10 and 20 μg/kg), were in the range 69.8-103.3% with relative standard deviations (RSDs) ≤ 6.9% for the 16 tested antibiotics. Matrix effects ranging from -47.2 to -13.5% were observed for all the analytes, and the limits of quantitation (LOQ), which ranged from 4.93 to 26.21 μg/kg, were much lower than the maximum residue limits (MRLs) set by various regulatory authorities. Ten samples from a market were tested, and none of the target analytes were detected. Thus, a simple and versatile protocol has been developed to detect and quantify 16 antibiotics in duck meat samples.