Validation of a liquid chromatography–tandem mass spectrometric method for the quantification of eight quinolones in bovine muscle, milk and aquacultured products Original Research Article

Quinolones are a group of structurally related antibacterial agents. Over the present decade there has been a significant and progressive increase in the use of this class of antibiotics in animal production. As a consequence the increased use of quinolones can promote the resistance of bacteria. To protect the consumers health, Maximum Residue Limits (MRL) have been established in edible animal matrices by the European Union. A liquid chromatography–tandem mass spectrometric (LC–MS2) method was developed and validated for the simultaneous quantification of eight quinolones at MRL level in bovine muscle, milk and aquacultured products. The studied quinolones were enrofloxacin, ciprofloxacin, sarafloxacin, danofloxacin, oxolinic acid, flumequine, difloxacin and marbofloxacin. The method involved a single solid-phase extraction followed by the analysis of all quinolones in a single chromatographic run using LC–ESI–MS2. Quinine was selected as internal standard. This paper consists of two parts: the discussion of the analytical method and the discussion of the different validation parameters according to Commission Decision 2002/657/EEC.