建立了膜透析/高效液相色谱-串联质谱法（MD/HPLC-MS/MS）检测畜产品中克伦特罗、莱克多巴胺、沙丁胺醇等9种β-受体激动剂的新方法。样品经乙酸铵缓冲液提取和β-葡萄糖苷醛甙酶/芳基硫酸酯酶酶解，采用标准再生纤维素膜（RC，截留分子量MWCO：1000D）透析净化，β-受体激动剂通过膜渗入透析液中，透析液用环已烷-乙酸乙酯（4：1）萃取，经Waters Xbridge C18色谱柱进行分离，以0.1%甲酸水和乙腈作为流动相进行梯度洗脱，电喷雾正离子（ESI+）模式电离，多反应监测（MRM）模式进行检测，外标法定量。结果表明，9种β-受体激动剂在0.5-10 μg/kg浓度范围内线性关系良好。方法的定量限为0.5 μg/kg，在0.5、1.0、2.5 μg/kg 3个添加水平的回收率为72.5%~92.6%, 相对标准偏差（n=6）在4.1%~12.7%之间。该方法采用膜透析技术进行净化，无需使用昂贵的固相萃取柱，适用于畜产品中9种β-受体激动剂的经济、高灵敏度的分析检测。

A new method based on membrane dialysis/high performance liquid chromatography-tandem mass spectrometry (MD/HPLC-MS/MS) was developed for the analysis of nine β-agonist residues (e.g., clenbuterol, ractopamine, salbutamol) in livestock products. The samples were extracted with ammonium acetate buffer, enzymolyzed by β-glucuronidase/arylsulfatase, and purified with a standard-grade regenerated cellulose dialysis membrane (RC, MWCO: 1000 D). The residues of β-agonists were infiltrated through the membrane into the dialysis solution, which was extracted with cyclohexane-ethyl acetate (4:1). The β-agonists were separated with Waters Xbridge C18 columns using a gradient elution with 0.1% formic acid-acetonitrile as the mobile phase. The β-agonists were detected by positive electrospray ionization (ESI+) in the multiple reaction monitoring (MRM) mode, and the quantification analysis was performed by an external standard method. The results showed that the nine β-agonists had good linearities in the range from 0.5 μg/kg to 10 μg/kg. The limits of quantitation for all β-agonists were 0.5 μg/kg. The recoveries of these analytes varied from 72.5% to 92.6% at the spiked levels of 0.5 μg/kg, 1.0 μg/kg, and 2.5 μg/kg. The relative standard deviation of the method varied from 4.1% to 12.7% (n = 6). The method was based on membrane dialysis and expensive solid-phase extraction cartridges were not required. Thus, this method is economical, highly sensitive, and suitable for the determination of the nine β-agonists residues in livestock products.

国家质检总局科技计划项目（2013IK178）；质检公益性行业科研专项（201310143）；国家科技支撑计划（2012BAK08B01）