新型强阳离子交换在线净化固相萃取整体柱与液相色谱串联质谱联用测定猪肉中的克伦特罗

Determination of Clenbuterol in Pork by On-line Cleanup Solid PhaseExtraction with Novel Strong Cation-exchange Monolithic ColumnCoupled with Liquid Chromatography-Tandem Mass Spectrometry

以甲基丙烯磺酸钠(SMAS)为单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,在内径为4.6mm的不锈钢柱管中聚合得到一种新型强阳离子交换在线净化整体柱。扫描电镜图显示该整体柱结构均匀、连续、多孔。将其用作萃取介质,结合高效液相色谱-串联质谱检测猪肉中残留的克伦特罗。结果表明,该整体柱能够有效地对猪肉中的克伦特罗富集净化,方法的线性范围为0.05～10.0μg/L,相关系数(r)为0.9988,定量下限为0.5μg/kg,完全满足我国对该类药物残留的限量要求。方法在0.5、1.0、5.0μg/kg 3个加标水平下的平均回收率分别为91%、94%、96%,相对标准偏差分别为4.9%、4.5%、3.4%。该在线净化液相色谱串联质谱法简单、高效、准确,可用于日常检测。

A novel strong cation-exchange monolithic column was prepared in a stainless steel column（4.6 mm in diameter） via the free radical polymerization of sodium methyl allyl sulfonate（SMAS） as monomer and ethylene glycol dimethacrylate（EDMA） as crosslinking agent.Scanning electron microscope image showed the resultant monolithic column matrix exhibited a continuous,porous and uniform structure.The on-line cleanup solid phase extraction was realized on the monolithic column and the determination of clenbuterol in pork was carried out by high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）.The result indicated that clenbuterol in pork sample was effectively enriched and purified by the prepared monolithic column.The calibration curve was linear in the range of 0.05-10.0 μg/L for clenbuterol with a correlation coefficient of 0.998 8.The limit of detection（LOD） for clenbuterol in pork was 0.5 μg/kg,which agreed with the standards regulated by the National Standards of the People＇s Republic of China.The average recoveries at three spiked levels of 0.5,1.0,5.0 μg/kg were 91%,94%and 96% with relative standard deviations（RSDs） of 4.9%,4.5% and 3.4%,respectively.With advantages of simplicity,reliable and sensitivity,the method was successfully applied in the determination of clenbuterol in pork samples.