ABSTRACT
HPLC with fluorescence detection is considered for confirmatory analysis of group B veterinary drugs by the European Union legislation. A procedure for confirming the presence of anti-inflammatory non-steroidal drug (NSAID) residues in bovine milk by reversed phase high-performance liquid chromatography with fluorescence detection is herein described. The native fluorescence of nine drugs belonging to different NSAID sub-classes, namely flurbiprofen, carprofen, naproxen, vedaprofen, 5-hydroxy-flunixin, niflumic acid, mefenamic acid, meclofenamic acid and tolfenamic acid, allowed for detection in bovine milk down to 0.25-20.0 microg/kg. Confirmation of the nine NSAIDs is attained by fluorescence detection at characteristic excitation and emission wavelengths. The procedure described is simple and selective. Limits of quantification (LOQs) ranging between 0.25 and 20 microg/kg were measured; satisfactory trueness and within-laboratory reproducibility data were calculated at LOQ spiking levels, apart from 5-hydroxy-flunixin. The procedure developed is used in our laboratory for confirmation of each one of the above mentioned NSAIDs in bovine milk, to support results after HPLC quantitative analysis with UV-vis detection.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/analysis , Chromatography, High Pressure Liquid/methods , Drug Residues/analysis , Milk/chemistry , Animals , Cattle , Chromatography, High Pressure Liquid/instrumentation , Food Contamination/analysis , Limit of Detection , Spectrometry, FluorescenceABSTRACT
In this work we present an in-house validation study for the confirmatory analysis of chloramphenicol (CAP) in muscle according to the Commission Decision 2002/657/EC requirements. CAP is extracted in acetonitrile and after liquid-liquid partitioning with n-hexane is identified and quantitatively determined by ion trap liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI-MS/MS) analysis in the negative ion mode. CAP was identified using the precursor ion and at least two product ions, meeting the qualitative and quantitative criteria set by the European Commission in the Decision 2002/657/EC for confirmation of prohibited veterinary drug residues. We calculated mean drug recoveries, CCalpha and CCbeta of the method, and reported data on specificity, ruggedness and within-laboratory reproducibility. Finally, we point out and discuss some problems and questions arising from controversy about the application of Decision 2002/657/EC.
