Analysis of selected veterinary antibiotics in fish by micellar liquid chromatography with fluorescence detection and validation in accordance with regulation 2002/657/EC

A simple and sensitive method was optimised and validated for the simultaneous analysis of five quinolones (oxolinic acid, flumequine, enrofloxacin, difloxacin and sarafloxacin) in different fish muscles. Analytical separation was performed in less than 18 min using a C18 column with fluorescence detection and a micellar solution of 0.065 M sodium dodecyl sulphate, 12.5% propanol and 0.5% triethylamine buffered at pH 3 as the mobile phase. The method was fully validated in accordance with European Union Decision 2002/657/EC. Selectivity, linearity, decision limit, detection capability, detection and quantification limits, recoveries, and robustness were determined. Therefore, the micellar method was successfully applied to quantitatively determine quinolones in spiked muscle fishes, and the recoveries obtained were in the 87–110% range. High extraction efficiency for the quinolones was obtained without matrix interference in the extraction process and in the subsequent chromatographic determination. No organic solvent was used during the pretreatment step.