Multi residue determination of the penicillins regulated by the European Union, in bovine, porcine and chicken muscle, by LC-MS/MS.

A multiresidue analysis method was developed to determine the content of penicillins in bovine, porcine and chicken muscle tissues. The procedure involves solid phase extraction (SPE) and subsequent analysis by liquid chromatography coupled with tandem mass spectrometry detection (LC-MS/MS) set by the European Union (EU) for all compounds. The method was validated according to EU guideline 2002/657/EC. The LOQ in tissues are below the maximum residue limits (MRLs) and appropriate quality parameters in terms of linearity, accuracy (recoveries higher than 70% for all antibiotics and animal tissues except for AMOX with 50% of recovery) and precision (in terms of intra and inter day with values lower than 12% in all cases) are obtained for the developed method. A study concerning to the matrix effect was made and it was concluded that similar matrix effect could be found in beef, pig and chicken. The method was applied to the analysis of samples of chicken from animals treated with amoxicillin.