高分辨质谱定性筛查牛奶和奶粉中兽药残留

目的 建立高分辨质谱定性筛查牛奶和奶粉中兽药残留的高通量方法。方法 样品经乙腈、QuEChERS盐包提取, 采取改良的3种不同方式QuChERS、高分辨质谱(high resolution mass spectrometry, EMR)、固相萃取(solid phase extraction, SPE)]净化提取液, 用液相色谱联用高分辨质谱(liquid chromatography-high resolution mass spectrometry, LC-HRMS)筛查了牛奶和奶粉中138种兽药残留, 建立兽药信息数据库, 并用截断值(Vcut-off, 判断阳性和阴性样品的临界值)作为评估筛查方法的指标。结果 改良的QuChERS可以获得更高的回收率, 当截断值(Vcut-off)设定为0.2时, 在2种加标水平下, 有109种兽药通过了筛查方法验证的要求, 假阳性和假阴性概率均低于5%。结论 此方法适用于牛奶和奶粉中多兽药残留的定性筛查, 一针进样可以得到109种兽药残留的筛查信息, 方法假阳性和假阴性概率在规定的目标物浓度下都低于5%。

Qualitative screening of veterinary drug residues in milk and milk powder by high resolution mass spectrometry

Objective To establish a high throughput method of qualitative screening of veterinary drug residues in milk and milk powder by high resolution mass spectrometry. Methods The samples were extracted with acetonitrile and QuEChERS salt packs, and the extraction solution was purified by 3 different methods QuChERS, high resolution mass spectrometry (EMR), and solid phase extraction (SPE)]. Total of 138 veterinary drug residues in milk and milk powder were screened by liquid chromatography-high resolution mass spectrometry (LC-HRMS), and a database of veterinary drug information was established, with cutoff values (Vcut-off)(Critical value of negative samples) as an indicator to evaluate screening methods. Results Improved QuChERS could achieve higher recoveries. When the cut-off value (Vcut-off) was set to 0.2, there were 109 veterinary drugs those passed the verification requirements of the screening method at 2 levels of spiking, the probability of false positives and false positives was less than 5%. Conclusion This method is suitable for the qualitative screening of multiple veterinary drug residues in milk and milk powder. A single injection can obtain screening information for 109 veterinary drug residues. This method has a false positive and false negative probability of less than 5% at the specified target concentration.