Multiresidue determination of fluoroquinolone antibiotics in eggs using liquid chromatography–fluorescence–mass spectrometryn Original Research Article

An efficient multiresidue method for determination of fluoroquinolone antibiotics in eggs has been developed, in which quantitation and confirmation are achieved simultaneously using fluorescence and MSn. With this method, eight fluoroquinolones were analyzed in fortified egg samples at levels of 10–100 ng g−1. Recoveries for desethylene ciprofloxacin, norfloxacin, ciprofloxacin, danofloxacin, enrofloxacin, orbifloxacin, sarafloxacin and difloxacin were generally in the range 60–100%, with excellent relative standard deviations. The limits of quantitation ranged from 0.1 to 2 ng g−1 in mixed egg. Confirmation was achieved by monitoring the ratios of two prominent product ions in MS2 (desethylene ciprofloxacin) or MS3 (all others). The method was found to be applicable to the analysis of egg whites and also egg yolks, with limits of quantitation ranging from 0.1 to 7 ng g−1 (egg white) and 0.1–1.5 ng g−1 (egg yolk). ENRO-incurred mixed eggs, egg whites and egg yolks were also successfully analyzed using this method.