Determination of flumequine, nalidixic acid and oxolinic acid in shrimps by high-performance liquid chromatography with fluorescence detection

A simple high-performance liquid chromatography (HPLC) method with fluorescence detection is presented for the determination of the quinolones flumequine, nalidixic acid and oxolinic acid in shrimps. The pharmaceuticals were extracted from the matrix with acetonitrile, purified by liquid-liquid extraction and analysed by HPLC with fluorescence detection at excitation wavelength of 312 nm and emission wavelength of 368 nm. The method has been validated according to the recommendations of the European Commission Decision 2002/657/EC under the consideration of specificity, trueness and precision as well as decision limit CC alpha and detection capability CC beta. The results of the validation demonstrate that the method is suitable to verify surely quinolone residues in shrimps and to decide with an estimated certainty if the investigated sample complies the European Council Regulation 2377/90/EEC or not. Furthermore, shrimp retail products of the years 2004 and 2005 were investigated with the developed HPLC-method.