Validation of antibiotics in catfish by on-line solid phase extraction coupled to liquid chromatography tandem mass spectrometry

► Validation of 13 antibiotics in catfish was carried out by a XLC-MS/MS method. ► A survey of contamination level on catfish in local markets was carried out. ► Samples giving positive results (16 out of 107) were analysed by proposed method. ► Five out of 13 antibiotics were found in the 16 samples. ► Tetracycline was detected in 10 samples but in concentrations lower than the MRL.