A method was established for the determination of clenbuterol and ractopamine in pork based on Polymer monolith microextraction coupled with high performance liquid chromatography-tandem mass spec-trometry (HPLC-MS/MS).The samples was extracted by ammonium acetate buffer and further purified by an PMME,which was eluted by methanol.The target compounds were assayed by HPLC-MS/MS with gradient elu-tion using methanol and 0.1%of formic acid aqueous solution as mobile phases.The mass spectrometric acqui-sitions were carried out by means of multiple reaction monitoring (MRM) in electrospray positive ionization mode. The clenbuterol linearities(R2>0.99) were achieved over the range of 0.015μg/L-1.00μg/L based on the internal standard calibration of clenbuterol-D9, the quantification limits of the method were 0.05 μg/kg.The mean recoveries of the clenbuterol (spiked at three concentration levels) ranged from 88.9%to 105.0%, with the relative standard deviations (RSDs) no more than 10 %. The ractopamine linearities (R2>0.99) were achieved over the range of 0.15μg/L-10.0μg/L based on the internal standard calibration of ractopamine-D 3, the quantification limits of the method were 0.50μg/kg.The mean recoveries of the clenbuterol (spiked at three concentration levels) ranged from 89.9%to 105.0%, with the relative standard deviations (RSDs) no more than 10%. This proposed method is simple,sensitive,reproducible,and complied with the regulations for the determination of trace contaminants residues in pork matrices.%研发聚合物整体柱微萃取（Polymer monolith microextraction， PMME）柱，建立猪肉中克伦特罗和莱克多巴胺的高效液相色谱-串联质谱（HPLC-MS/MS）检测方法。样品用乙酸铵缓冲液提取，通过聚（甲基丙烯酸－乙二醇二甲基丙烯酸酯（p（MAA-co-EGDMA））柱进行富集净化，用甲醇洗脱，采用HPLC-MS/MS进行测定，梯度洗脱，流动相为甲醇和含0.1%的甲酸水溶液；质谱采集模式为电喷雾正离子多反应监测模式。以克伦特罗-D 9为内标，克伦特罗的的线性范围为0.015μg/L～1.00μg/L，相关系数（R2）大于0．99，定量限为0.05μg/kg，3个不同水平的加标平均回收率为88.9%～105.0%，相对标准偏差小于10%。以莱克多巴胺-D3为内标，莱克多巴胺的的线性范围为0.15μg/L～10.0μg/L，相关系数（R2）大于0.99，定量限为0.50μg/kg，3个不同水平的加标平均回收率为89.9%～105.0%，相对标准偏差小于10%。该方法具有操作简单、灵敏度高、重现性好，试剂用量少等特点，符合食品样品中痕量污染物的检测要求。
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