Development and validation of a methodology to qualitatively screening veterinary drugs in porcine muscle via an innovative extraction/clean-up procedure and LC-MS/MS analysis.

A qualitative multiresidue method that facilitates rapid monitoring of veterinary drugs in porcine muscle is described. The method comprises the application of an innovative extraction/clean-up procedure, namely liquid-liquid extraction with partition at very low temperature (LLE-FPVLT), and analysis by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Besides the high selectivity, sensitivity and specificity, this high-throughput method proved to be quite general as 34 veterinary drugs (from six distinct classes: tetracyclines, sulfonamides, penicillins, quinolones, macrolides and benzimidazoles) could be successfully detected. The whole screening procedure was validated according to the directives from European Commission Decision 2002/657/EC and guidelines for the validation of screening methods. Acceptable values for the evaluation parameters were achieved for all analytes (except for ampicillin, clindamycin and erythromycin). Finally, these very promising results have strengthened the possibility of inclusion of such a methodology as an integral part of the National Residue Control Plan scope of the Ministry of Agriculture, Livestock and Food Supply of Brazil.