A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method and ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) were optimized and validated for 16 antibiotics belonging to three families (macrolides, quinolones, and sulfonamides) that were found in preserved eggs. Samples were extracted in 4 mL water and 10 mL acetonitrile with 1% acetic acid and subjected to a cleanup procedure using dispersive solid-phase extraction with C18 and primary secondary amine sorbents, prior to detection by UHPLC-MS/MS. Matrix-matched calibration was used for quantification to reduce the matrix effect with limits of quantification in the range of 0.3-3.0 μg/kg. Validation of the method was conducted by recovery and precision experiments. Recoveries of the spiked samples ranged from 73.8% to 127.4%, and the intra- and inter-day relative standard deviations were lower than 21.2% and 22.3%, respectively. This method was successfully applied to the analysis of antibiotics in preserved egg samples.
- Preserved eggs