RESUMEN
A multiresidue and multiclass method based on liquid chromatography-tandem mass spectrometry for the determination of antibacterials was developed and validated for screening purposes. This method can be applied to commonly used drugs in veterinary medicine such as tetracyclines, quinolones and sulfonamides. Sample preparation consists in cell disruption with sand (previously purified and washed with EDTA 100 mM) followed by protein precipitation with acidified acetonitrile. Validation was conducted in accordance to European Union requirements (2002/657/EC) for qualitative methods covering detection capability (CCß), selectivity, specificity and stability. The method enabled the detection of 21 different drugs and had a false-compliant rate of <5% (ß error) at between 25% and 50% of the maximum residue levels established by legal authorities. The methodology was successfully applied to incurred poultry samples.