Determination of tetracyclines in multi-specie animal tissues by pressurized liquid extraction and liquid chromatography-tandem mass spectrometry

A specific, sensitive and robust pressurized liquid extraction (PLE) and liquid chromatography tandem mass spectrometry (LC-MS/MS) method for determining tetracycline, chlortetracycline, oxytetracycline and doxycycline in bovine, swine, poultry and lamb muscle tissues is presented. PLE was performed using an ASE (R) 200 from Dionex and water as extractant, followed by solid-phase extraction (SPE) using an Oasis HLB cartridge. The method was validated for beef, chicken, pork and lamb meat in compliance with the requirements set by Commission Decision, 2002/657/EC [Commission Decision 2002/657/EC (2002). Implementing Council Directive 96/23/EC concerning the performance of analytical methods and interpretation of results. official Journal of European Communities, L239, 66-98. (Available at: http://europe.eu.int)]. The average recoveries of the different meat samples, spiked with the four tetracyclines at three levels (1, 100 and 200 mu g kg(-1) of each tetracycline), were always higher than 89% with intraday and interday precision lower than 15% and 17%. respectively. A good linearity was established for the four tetracyclines in the range from 5 to 10,000 mu g kg(-1) with r > 0.995. The limits of quantification (LOQs) were between 0.5 and 1 mu g kg(-1), which are well below the tolerance levels set by the European Union. The decision limit (CC alpha) and the decision capability (CC beta) were in the range 101-116 and 112-130 mu g kg(-1), respectively. Compared with previous methods, sample preparation time required for the analysis and LOQs, are reduced. The method demonstrated its successful application for the analysis of 100 meat samples. Two samples of beef and one sample of chicken out of 25 of each type tested positive while none of 25 samples of either, lamb or pork, tested positive. (C) 2009 Elsevier Ltd. All rights reserved.