Validation of an HPLC-UV method according to the European Union Decision 2002/657/EC for the simultaneous determination of 10 quinolones in chicken muscle and egg yolk

Herein two different methods are proposed for the determination of 10 quinolones (enoxacin, ofloxacin, norfloxacin, ciprofloxacin, danofloxacin, enrofloxacin, sarafloxacin, oxolinic acid, nalidixic acid and flumequine) in chicken muscle and egg yolk. Two different HPLC systems were used comparatively and the respective methods were fully validated. The analytes were initially extracted from chicken muscle and egg yolk and purified by a solid phase extraction using LiChrolut RP-18 cartridges. Recoveries varied between 96.6 and 102.8% for chicken muscle and 96.4–102.8% for egg yolk. HPLC separation was performed at 25 °C using an ODS-3 PerfectSil®Target (250 mm × 4 mm) 5 μm analytical column (MZ-Analysentechnik, Germany). The mobile phase consisted of a mixture of 0.1% trifluoroacetic acid (TFA)–ACN–CH3OH, delivered by a gradient program, different for each method. In both cases caffeine was used as internal standard at the concentration of 7.5 ng/μL. Column effluent was monitored using a photodiode array detector, set at 275 and 255 nm. The developed methods were validated according to the criteria of Commission Decision 2002/657/EC. The LODs for chicken muscle varied between 5.0 and 12.0 μg/kg and for egg yolk was 8.0 μg/kg for all examined analytes.