Danofloxacin depletion from muscle plus skin tissue of European sea bass (Dicentrarchus labrax) fed danofloxacin mesylate medicated feed in seawater at 16 °C and 27 °C

Residue depletion of danofloxacin was investigated in European sea bass after a multiple (5 days) in-feed administration of danofloxacin mesylate (10 mg/kg bw per day) under experimental field conditions at water temperature of 16 °C and 27 °C. Ten fish per sampling point were examined during and after treatment. Samples of muscle plus skin in natural proportions were analyzed for danofloxacin determination by Ultra-Performance Liquid Chromatography equipped with an Ultraviolet Photodiode Array Detector (UPLC-PDA). Danofloxacin concentrations in muscle tissues increased during medication period and then decreased rapidly. The elimination half-lives were estimated to be t1/2 = 16.87 h and 21.13 h at 27 °C and 16 °C, respectively. Withdrawal periods (Wt) were calculated after medication using the WT1.4 program and were found to be at 95% tolerance limit, 7 and 4 days at 16 °C and 27 °C, respectively.