A LC-MS/MS method was validated for the simultaneous quantification of 4 quinolones (oxolinic acid, enrofloxacine, ciprofloxacine, norfloxacine) and 4 sulfonamides (sulfamethoxypyridazine, sulfadoxine, sulfadimidine, sulfamerazine) on fish muscle following the European Union's (EU) criteria for the analysis of veterinary drug residues in foods. One gram of sample was extracted by acidic acetonitrile (0.5 mL of 0.1% formic acid in 7 mL of ACN), followed by LC-MS/MS analysis using an electrospray ionization interface. Typical recoveries of the 4 quinolones in the fish tissues ranged from 85 to 104%. While those of the sulfonamides ranged from 75 to 94% at the fortification level of 5.0 μg/kg. The decision limits (CCα) and detection capabilities (CCβ) of the quinolones were 1.35 to 2.10 μg/kg and 1.67 to 2.75 μg/kg, respectively. Meanwhile, the CCα and CCβ of the sulfonamides ranged from 1.62 μg/kg to 2.53μg/kg and 2.01μg/kg to 3.13 μg/kg, respectively.

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