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

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, 3.5 μm)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2.5~100 μg/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。

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

An analytical method was established for the simultaneous determination of six classes 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 compounds were separated on a ZORBAX SB-C18 column (100 mm×2.1 mm, 3.5 μm) with acetonitrile-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 accurate masses of all the compounds and fragment ions upon Target MS/MS. The correlation coefficients 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, sensitive, and suitable for the simultaneous determination of multi-classes of veterinary drugs in pork.