超高效液相色谱-四极杆-飞行时间质谱法同时测定猪肉中多类兽药残留

Simultaneous determination of multi-classes of veterinary drug residues in pork by ultra performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry

建立了超高效液相色谱-四极杆-飞行时间质谱（ UPLC-Q-TOF MS）快速检测猪肉中6类33种兽药残留的分析方法。样品采用QuEChERS方法进行前处理（5％（v／v）乙酸乙腈溶液提取，C18和 NH2吸附剂净化），采用ZORBAX SB-C18色谱柱（100 mm×2.1 mm，3.5μm）分离，以乙腈-0.1％（v／v）甲酸水溶液（含5 mmol／L乙酸铵）为流动相，梯度洗脱，Q-TOF MS电喷雾正离子模式分析检测。在全扫描采集模式下，以准分子离子峰的峰面积定量，以化合物的色谱保留时间和精确质量数定性。在Target MS／MS采集模式下，通过碎片离子的精确质量数进一步确证化合物。33种化合物在各自的线性范围内均呈现良好的线性关系，相关系数均大于0.99，33种化合物的定量限（S／N＝10）为2.5～100μg／kg，添加回收率为67.0％～109.0％，相对标准偏差（RSD， n＝6）均不高于15.1％。该方法简便、快速、灵敏，适用于猪肉中多类兽药残留的同时检测。

An analytical method was established for the simultaneous determination of six clas-ses of 33 veterinary drug residues in pork by ultra performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry （ UPLC-Q-TOF MS ） . The QuEChERS method has been validated for the extraction. In this method, the sample was extracted by acetonitrile containing 5%（ v/v） acetic acid and cleaned-up with C18 and NH2 adsorbents. The extract was measured directly by UPLC-Q-TOF MS with electrospray ionization in positive mode. The com-pounds were separated on a ZORBAX SB-C18 column （100 mm×2.1 mm, 3.5μm） with acetoni-trile-0.1% formic acid containing 5 mmol/L ammonium acetate as mobile phases under gradient elution. The confirmatory analysis was carried out by determining the retention times and accu-rate masses of all the compounds and fragment ions upon Target MS/MS. The correlation coeffi-cients of the 33 veterinary drugs were more than 0.99 within their linear ranges. The limits of quantification （ LOQs） were 2.5-100 μg/kg. The recoveries ranged from 67.0% to 109.0% with the relative standard deviations （ RSDs, n=6） not more than 15.1%. The method is rapid, sensi-tive, and suitable for the simultaneous determination of multi-classes of veterinary drugs in pork.