Simultaneous Determination of 24 Sulfonamide Antibiotics in Fish Products by QuEChERS with Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A method for the simultaneous determination of 24 sulfonamide antibiotics including sulfamethazine, sulfaguanidine, sulfanilamide and so on in fish products was established by QuEChERS coupled with ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). The optimal experimental conditions were determined by optimizing the chromatographic and mass spectrometric conditions and the QuEChERS pre-treatment technique. The samples were extracted by acetonitrile under ultrasonication, and then purified by C₁₈ and anhydrous MgSO₄. The solvent was detected by UPLC-MS/MS after filtering through 0.20 μm microporous membrane. The separation was performed on an Eclipse XDB-C₁₈ column (4.6 mm × 100 mm, 1.8 μm) using acetonitrile −0.1% formic acid aqueous solution as the mobile phase, and determined with positive ion mode of electrospray ionization (ESI) under multiple reaction monitoring (MRM). Then the matrix matching external standard method was used for quantitative analysis. The results indicated that the 24 sulfonamide antibiotics showed good linearity in the respective linear range with the correlation coefficients (r) higher than 0.999. The average recoveries at three spiked levels of 5, 10 and 50 µg/kg ranged from 80.0% to 116.4% with the relative standard deviation (RSD) of 0.8%~9.4% (n=7). Moreover, the limits of detection (LOD) were 0.01~0.48 µg/kg and the limits of quantification (LOQ) were 0.02~1.59 µg/kg. The method was simple, rapid, selective and sensitive for the high-throughput detection of 24 sulfonamide antibiotics in fish products.