Rapid method for the determination of non-steroidal anti-inflammatory drugs in animal tissue by liquid chromatography–mass spectrometry with ion-trap detector

A rapid and new liquid chromatography–mass spectrometry with ion-trap detection method for the determination of meloxicam (MLX), flunixin meglumine (FLU), carprofen (CPF), and tolfenamic acid (TOLF) in animal tissue is described.MRLs between 10 and 500 μg kg−1 in muscle and between 65 and 1000 μg kg−1 in liver, from different animal species have been established in the EU for these compounds.After chemical hydrolysis, an organic extraction from homogenised tissue was performed. Final extract was injected in a liquid chromatograph with an ion-trap mass spectrometer with electrospray interface.Four identification points (one precursor and two product ions) and a minimum of one ion ratio was monitored for each compound.For quantitative purposes flunixin-D3 (FLU-D3) was used as internal standard.The method was validated using fortified blank muscle and liver from different animal species according to the 2002/657/EC European decision criteria.The decision limits (CCα) and detection capabilities (CCβ) were determined and their values were at concentrations near the MRL for each substance.