液相色谱-四极杆/静电场轨道阱高分辨质谱快速分析动物源性食品中多肽类药物残留

建立了液相色谱-四极杆/静电场轨道阱高分辨质谱(Q/Exactive)分析鸡肉、鸡肝、鸡肾、猪肉、猪肝、猪肾、牛奶和鸡蛋中粘杆菌素A、粘杆菌素B、多粘菌素B、杆菌肽A和维吉尼霉素M的方法。动物源性食品采用1%(体积分数)乙酸乙腈-水(体积比为8∶2)超声提取,提取液直接经C18液相色谱柱分离。在电喷雾正离子模式下,四极杆质谱在m/z 1.2隔离窗口下过滤一级带电离子,高分辨静电场轨道阱质谱在35 000分辨率下进行目标物子离子全扫描(targeted-MS2)。根据5种多肽类药物的高分辨分子离子峰、同位素分布、特征子离子信息建立数据库,采用Trace Finder 3.0软件实现定性检索。为解决多肽类药物残留测定结果重复性差的难题,系统地评价了5种多肽类药物的关键操作技术条件,发现导致该类药物降解的主要因素包括:提取时间、玻璃器皿、存放时间。该方法测定5种多肽类药物时,测定结果的质量精度均小于5×10-6,维吉尼霉素M的定量限(LOQ)为0.5μg/kg,另外4种多肽类药物的LOQ均为10μg/kg。在0.25~500μg/kg范围内,5种多肽类药物的峰面积与质量浓度呈良好的线性关系,相关系数R2≥0.993 1,方法回收率为67.4%~108.9%,相对标准偏差为4.5%~17.2%。该方法操作简单,测定结果准确,可用于动物源性食品中多肽类药物残留的高通量测定。

Quick determination of polypeptide drug residues in animal-origin foods by high performance liquid chromatography-quadrupole/orbitrap high resolution mass spectrometry

An analytical method was developed to determine colistin A (CLA), colistin B (CLB), polymyxin B (PLB), bacitracin A (BTA), virginiamycin M (VGM) by combined quadrupole/orbitrap high resolution mass spectrometry (Q/Exactive) in meat, liver, kidney, milk and egg. Animal-origin foods were extracted with acetonitrile containing 1% (v/v) acetic acid and water under the ultrasonic assisted condition. The samples were analyzed directly on a C₁₈ column. The charged ion in positive electrospray ionization (ESI⁺) mode entered quadrupole mass limited to isolation window m/z 1.2. Product ion scan was performed on 35000 resolution of orbitrap mass. According to some parameters of molecular ion, isotopic ion ratios, characteristic product ion, the searched database was built with the Trace Finder 3.0 software. To solve the problem of poor reproducibility of the detected results, this method evaluated systematically some critical operation procedures. Finally, contributory factors of degradation were discovered including extraction time, adsorption of glass vessels, storing period. Under the experimental conditions, accuracy errors of the five analytes were all less than 5×10^-6. The limits of quantification (LOQs) were 0.5 μg/kg for virginiamycin M and 10 μg/kg for the other four analysts. The good linear relationship was obtained in the range of 0.25-500 μg/kg (correlation coefficient (R²)≥0.9931). The method recoveries were 67.4%-108.9% and the relative standard deviations (RSDs) were 4.5%-17.2%. This method showed that it was simple, accurate and reliable. It will be applicable for high throughput determination of polypeptide antibiotic residues in animal-origin foods.