Abstract:

An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for the simultaneous determination of six tetracylines in aquatic products. Samples were extracted with 0.01 mol/L Na2EDTA/ Mcllvaine buffer solution. After filtrated and degreased by n-hexane, the extract was passed through Oasis HLB solid phase extraction column and eluted with methanol, and the eluate was then pooled together and evaporated until dryness under nitrogen and redissolved in 1.0 mL of dissolving solution. The solution was separated on a RP-UPLC column and detected by triplequadrupole MS. The electrospraying was operated in the positive ionization mode and the identification of analytes was achieved using multiple reaction monitoring (MRM) mode. Quantitation was carried out using the external standard method. The standard curves for all the compounds were linear over the concentration range of 5.0 to 50.0μg/kg with correlation coefficients between 0.9969 and 0.9999. The spike recoveries at four levels of 5.0, 10.0, 25.0, 50.0μg/kg ranged form 61% to 97%, and the relatives standard deviations (RSD) were in the range of 1.3% to 5.7%. The limits of detection of the method for the analytes were all 2.5μg/kg. Owing to the merits of simplicity, selectivity and sensitivity, the proposed method has been successfully applied to the determination of tetracyclines in aquatic products.

Key words: aquatic products, tetracyclin antibiotics, ultra performance liquid chromatography-tandem mass spectrometry (UPLC- MS/MS)