Submitted to: Analytica Chimica Acta
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/22/2002
Publication Date: 4/25/2003
Citation: SCHNEIDER, M.J., DONOGHUE, D.J. MULTIRESIDUE DETERMINATION OF FLUOROQUINOLONE ANTIBIOTICS IN EGGS USING LIQUID CHROMATOGRAPHY-FLUORESCENCE-MASS SPECTROMETRY. ANALYTICA CHIMICA ACTA. 2003. V. 483. P. 39-49. Interpretive Summary: Fluoroquinolones are a class of antibiotics which are currently used in both medical and veterinary applications. Use of these antibiotics in food producing animals has generated concern as the presence of these residues in food may lead to increased microbial resistance in humans. Thus, efficient methods are needed for the analysis of a variety of fluoroquinolone residues in meat and related products, such as eggs. We have now developed a method which allows for the simultaneous analysis of eight fluoroquinolones in mixed egg, egg white and egg yolk samples. This method uses liquid chromatography combined with two powerful detection techniques: fluorescence, for measurement of the amount of each fluoroquinolone present, and mass spectrometry-mass spectrometry, for confirmation of the identity of each fluoroquinolone present. Using this approach, we were able to simultaneously measure and confirm the identity of eight fluoroquinolones from both fortified and incurred mixed egg, egg white and egg yolk samples. The combination of measurement and confirmation in one experiment provides a highly efficient method for analysis of the fluoroquinolones and is a promising tool for use by regulatory agencies.
Technical Abstract: Fluoroquinolone antibiotics are currently used in both medical and veterinary applications. Use of these antibiotics in food animals has generated concern as the presence of these residues in food may contribute to increased microbial resistance in humans. Effective methods for analysis of fluoroquinolone residues in meat and related products, such as eggs, are thus needed. 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. Recoveries for desethylene ciprofloxacin (DCIP), norfloxacin (NOR), ciprofloxacin (CIP), danofloxacin (DANO), enrofloxacin (ENRO), orbifloxacin (ORBI), sarafloxacin (SAR) and difloxacin (DIF) were generally in the range of 60-100%, with excellent RSDs. The limits of quantitation ranged from 0.1-2 ng/g. Confirmation was achieved by monitoring the ratios of two prominent product ions in MS2 (desethylene ciprofloxacin) or MS3 (all others). The method was found applicable to analysis of egg whites and egg yolks, as well, with limits of quantitation ranging from 0.1-7 ng/g (egg white) and 0.1-1.5 ng/g (egg yolk). ENRO-incurred mixed eggs, egg whites and egg yolks were also successfully analyzed using this method.