Abstract:Turbots Scophthalmus maximus (BW 300~400 g) were kept in experimental tanks with aerated seawater at temperatures of 11～12 ℃. The fish were fed enrofloxacin (EF) medicated feed at a EF dosage of 30 mg/kg BW. per day for 7 consecutive days. Serum, muscle and liver tissues were taken from five turbots at days 1, 2, 4, 8, 12, 16, 22, 28, 36, 44, 54, 64, 74, 84, 94 after the last oral administration of EF. The three tissues were tested by high performance liquid chromatography (HPLC) with fluorescence detection, the minimum detection limit was 001 μg/ml, average recovery was 75～87% . The results showed that elimination of EF complied with the first order kinetics, and the equations of elimination curve of enrofloxacin in muscle, liver, serum were C=1.560e-0.031 0 t, C=1.147e-0.018 9 t and C=0.920e-0.027 1 t, respectively.The elimination half lives (T1/2elim β) were 22.53, 36.67, 25.57 d, respectively. It is suggested that a withdrawal time of more than 120 d at temperatures of 11～12 ℃ is appropriate for the elimination of enrofloxacin and ciprofloxacin in turbot.
