采用高效液相色谱-串联质谱法同时测定动物源性食品中4种β-兴奋剂克伦特罗、莱克多巴胺、沙丁胺醇、特布他林的残留量.样品用乙酸铵缓冲溶液提取,过LC-18 Sep Pak和LC-SCX Sep Pak固相萃取柱净化,将淋出液蒸发浓缩后用乙腈-水(10+90)定容.通过C18色谱柱分离,流出液供串联质谱测定,同位素内标法定量.4种β-兴奋剂克伦特罗、沙丁胺醇、莱克多巴胺、特布他林的质量浓度与其峰面积均呈线性关系,检出限(3S/N)分别为0.05,0.1,0.1,0.1 μg·kg-1.猪肝中克伦特罗、莱克多巴胺、沙丁胺醇、特布他林的回收率分别为91.8%~99.0%,98.3%~105.5%,76.8%~82.8%,75.1%~85.2%，相对标准偏差(n=7)均小于12.5%.

High performance liquid chromatography in hyphenation with tandem mass spectrometry (HPLC-MS/MS) was applied to the determination of residual amounts of 4 kinds of β-agonists,including celenbuterol,salbutamol,raotopamine and terbutalin in foodstuffs.The sample was extracted with ammonium acetate buffer solution,which was concentrated and purified by LC-18 Sep Pak and LC-SCX Sep Pak solid-phase extraction column.The eluate was evaporated to near dryness and diluted to a definite volume with acetonitrile-H2O(10+90) solution,and separated on the C18 column.The eluate was used for tandem MS analysis.External standard calibration of isotope was adopted in the determination.Linear relationships between values of peak area and mass concentration of celenbuterol,raotopamine,salbutamol and terbutalin were obtained,with their detection limits of 0.05,0.1,0.1,0.1 μg·kg-1 respectively.Values of recovery of celenbuterol,salbutamol,raotopamine and terbutalin in the range of 91.8%-99.0%,98.3%-105.5%,76.8%-82.8% and 75.1%-85.2% were found respectively in a sample pig liver.Values of RSD′s (n=7) found were less than 12.5%.