[Simultaneous determination of nine beta-agonist residues in animal derived foods by ultra performance liquid chromatography-tandem mass spectrometry].

An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/ MS) method was established for the simultaneous determination of terbutaline, cimaterol, salbutamol, fenoterol, clorprenaline, ractopamine, clenbuterol, tulobuterol, penbutolol residues in animal derived foods. After enzymolysis, the samples were extracted by perchloric acid, centrifuged, neutralized, followed by liquid-liquid extraction with ethyl acetate and tert-butyl methyl ether, separately. The combined extracts were applied to a solid phase extraction MCX cartridge for cleanup. The separation of beta-agonists was performed on Waters Acquity UPLC system with a BEH C18 column (50 mm x 2.1 mm, 1.7 microm) and the gradient elution solvent of acetonitrile (containing 0.1% formic acid) and water (containing 0.1% formic acid) at a flow rate of 0.3 mL/min. The method was quantified by external standard method. The calibration curves were good linear between the peak areas and the concentrations of 0.25 - 5 microg/kg with the correlation coefficient r > 0.990. The limit of detection of the 8 beta-agonists was 0.1 microg/kg, and the limit of quantification was 0.25 microg/kg. The limit of detection of penbutolol was 0.25 microg/kg, and the limit of quantification was 0.5 microg/kg. The average recoveries from spiked animal tissues at three concentrations of 0.5, 1 and 2 microg/kg ranged 87.1% - 108.6%. The relative standard deviations of intra- and inter-batch were both less than 20%.