Determination of (fluoro)quinolone antibiotic residues in pig kidney using liquid chromatography-tandem mass spectrometry. I. Laboratory-validated method.

A new LC-MS/MS method has been developed for the multiresidue determination of 11 (fluoro)quinolone antibiotics (FQs), including acidic and amphoteric species, around their maximum residue level (MRL) in pig kidney. The procedure involves a common sample preparation by solid-phase extraction on disposable extraction cartridges followed by a fast reversed-phase liquid chromatography-tandem mass spectrometry analysis. The method was validated according to the Commission Decision 2002/657/CE. The accuracy of the method was satisfactory with recoveries included in the interval 80-100%. The precision results showed mean repeatability and reproducibility coefficients of 7.4% and 11.8%, respectively. Limits of quantification much lower than the MRLs could be obtained.