Abstract:

A high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method was developed for the simultaneous determination of 4 fluoroquinolone antibiotic residues in fish meat. In the method, analytes were extracted with acidified acetonitrile, cleaned up with n-hexane, concentrated to dryness under nitrogen, redissolved in 1 mL of mixed solution of acetonitrile and 1% formic acid (1:9, V/V), separated on a RP-HPLC column, detected by HPLC-MS/MS with positive electrospray ionization (ESI+) in multiple reaction monitoring (MRM) mode, and quantified using an external standard method. The standard curves for all analytes exhibited good linearity over the concentration range of 2 － 40 μg/kg with correlation coefficients (r2) beyond 0.997. The recoveries of 4 fluoroquinolone antibiotics in fish meat samples spiked at concentration levels of 4, 10 μg/kg and 20 μg/kg ranged from 79.9% to 98.1%, with relative standard deviations between 2.7% and 8.7%. The limits of detection (LOD) and limits of quantification (LOQ) of the developed method were in the ranges of 0.1－0.4μg/kg and 0.3－ 1.0 μg/kg, respectively. This method is characterized by simplicity, rapidity, high sensitivity, good reproducibility and better selectivity, and therefore can be used for identification and determination of fluoroquinolones in fish meat.

Key words: high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), fluoroquinolones, residues, fish