Determination of 28 β_2-agonists in pork by liquid chromatography-tandem mass spectrometry

Objective To establish a method for the determination of 28 β2-agonists in animal tissues by liquid chromatography-tandem mass spectrometry(LC-MS/MS).Methods The residues of β2-agonists in the test samples were extracted with 0.2 mol/L sodium acetate(pH5.2).After being cleaned up with column,concentrated and reconstituted,the residues were detected by liquid chromatography-mass spectrometry under multiple reaction monitoring(MRM) via positive-ion mode.Results The method showed a good linearity over the range of 2.5~25 μg/L for β2-agonists with r0.996.The average recoveries were 60.8%~116.6% at different spiked levels in pork,and the relative standard deviations were 1.74%~18.47%.The limit of quantitation was 0.500 μg/kg.Conclusion This method is highly sensitive,accurate and reproducible,and it is suitable for the detection of β-agonists in pork.