Determination of oxytetracycline in raw and cooked channel catfish by capillary electrophoresis.

摘要

Oxytetracycline (OTC) residues exceeding the 0.1 mg/kg tolerance concentration were detected by capillary electrophoresis (CE) in catfish (Ictalurus punctatus) fillets 18 h after oral feeding with OTC 37.5, 75.0 and 150.0 mg/kg medicated feed for 10days. The CE migration time of OTC was 10.9 min using a 24 cm X 25μm capillary under 8 kV constant voltage. The mean OTC recovery rates in spiked catfish were 92.9% over the concentrations of 0.1-25 mg/kg. Cooking procedures (frying, baking and smokingat 190deg C) could only reduce but not completely eliminate OTC residues in catfish fillets.