Determination of ractopamine in animal tissues by liquid chromatography-fluorescence and liquid chromatography/tandem mass spectrometry

A sensitive method was developed and validated for routine screening and confirmation of ractopamine residues in porcine and bovine muscle tissues. Muscle tissues were extracted with methanol and hydrolyzed with P-glucuronidase, followed by liquid extraction and solid-phase clean up. Ractopamine was quantified by liquid chromatography (LC) with fluorescence detection, using ritodrine as internal standard and confirmed by tandem mass spectrometry. Recoveries of ractopamine ranged between 80 and 117% in porcine tissues and 85 and 114% in bovine tissues at 1-4 ng g(-1) ractopamine. This procedure is suitable for routine monitoring, screening and confirmation of ractopamine residues in edible meat tissues, as mandated by regulatory agencies. (C) 2003 Elsevier Science B.V. All rights reserved.