基于质谱裂解机理的深加工羊肉制品中兽药残留非定向筛查技术研究

建立了一种基于质谱断裂机理的非定向筛查7类34种兽药残留的超高效液相色谱-四极杆-静电场轨道阱质谱(UHPLC-Q-Orbitrap MS)。采用数据非依赖采集模式进行质谱测定,基于标准化合物的保留时间、精确质量数、二级碎片离子信息进行定性筛选,通过解析分子离子的质谱碎裂过程与裂解机理,获得不同类别兽药的特征碎裂片段。结合特征离子,通过同位素离子峰信息与二级碎裂片段丰度比进行确证,构建非定向筛查方法。结果表明,34种兽药在各自的质量浓度范围内线性关系良好,相关系数(r^2)均大于0.99,检出限和定量下限分别为0.04~4.76μg/kg和0.07~8.24μg/kg,回收率为79.4%~110%,相对标准偏差为0.30%~7.5%。将所建方法应用于市售深加工羊肉制品中兽药残留的非定向筛查,检出样品含有磺胺二甲嘧啶以及标准数据库外的双氟沙星。该方法快速、准确、分析通量高,对于复杂基质中未知兽药残留鉴定具有重要意义。

Non-directional Screening of Veterinary Drug Residues in Deep processed Lamb Products Based on Mass Spectrometry Fragmention

An analytical method was developed for the non-directional screening of 34 residues in 7 categories of veterinary drugs by ultra-high performance liquid chromatography-hybrid quadrupole-orbitrap mass spectrometry(UHPLC-Q-Orbitrap MS)based on mass spectrometry fragmentation.The qualitative screening of the analytes was performed by MS in a data independent acquisition mode,based on retention time,accurate mass number,secondary fragmentation information of 34 veterinary drug standard substances.The characteristic fracture fragments of 7 categories of veterinary drugs were obtained by exploring the molecular ion mass spectrometry rupture process and cracking mechanism.A method for untargeted screening of target and non-target substances in deep-processed lamb products was established by combining the compound database with characteristic ion fragments in the data independent collection mode.Results showed that there were good linear relationships for 34 veterinary drugs in respective concentration ranges with their correlation coefficients(r^2)larger than 0.99.The limits of detection and quantitation were 0.04-4.76μg/kg and 0.07-8.24μg/kg,respectively.Average recoveries at three added levels ranged from 79.4%to 110%,with relative standard deviations(RSD)of 0.30%-7.5%.The method was applied in the non-directional screening of veterinary drug residues in commercially available deep-processed lamb samples,and difloxacin outside the standard library was also detected beside sulfamethazine.Hence,the proposed method is simple and efficient,and could be employed for accurate determination of veterinary drug residues in lamb products.