Hu Fengyang, Bian Kui, Liu Yahong, Su Yijuan, Zhou Tong, Song Xuqin, He Limin
National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong PC 510642, China.
National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong PC 510642, China.
J Chromatogr A. 2014 Nov 14;1368:52-63. doi: 10.1016/j.chroma.2014.09.074. Epub 2014 Oct 5.
A modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed for rapid determination of 26 veterinary antimicrobials in vegetables. Samples were extracted by single-phase extraction with acetonitrile-methanol (85:15, v/v) and citric buffer solution, followed by liquid-liquid partitioning with the addition of anhydrous magnesium sulfate and sodium chloride. A dispersive solid-phase extraction with primary secondary amine was applied for cleanup. Concentration and solvent exchange was performed prior to LC-MS/MS analysis. All matrix-matched calibration curves were linear with correlation coefficients (r) over 0.99. Recoveries for all the analytes spiked at 0.5 (1 or 1.5), 5 and 50 ng/mL were in the range of 60.0-98.0%, except for sulfaquinoxaline, sulfaclozine and doxycycline, with relative standard deviations below 25% for the low concentration level, 20% for the medium and 15% for the high. The decision limits and the detection capabilities of the analytes ranged from 0.005 to 0.5 μg/kg and from 0.02 to 1.5 μg/kg, respectively. The method was developed and validated in accordance with romaine lettuce matrix, and higher recovery rates were obtained from the other five kinds of vegetables including white radish, Chinese cabbage, cucumber, string bean and green pepper. Matrix effects of different vegetables were evaluated and signal suppression effect was observed for the majority of 26 analytes. Finally, the method was applied to the analysis of real samples collected from the agricultural areas in the vicinity of local pig farms, and the phenomenon of vegetables contaminated by antimicrobials residues is provoking.
建立了一种改进的快速、简便、廉价、高效、耐用且安全的（QuEChERS）方法，并结合液相色谱串联质谱法（LC-MS/MS）用于快速测定蔬菜中的26种兽用抗菌药物。样品先用乙腈 - 甲醇（85:15，v/v）和柠檬酸缓冲溶液进行单相萃取，然后加入无水硫酸镁和氯化钠进行液 - 液分配。采用伯仲胺进行分散固相萃取净化。在LC-MS/MS分析之前进行浓缩和溶剂交换。所有基质匹配校准曲线均呈线性，相关系数（r）大于0.99。除磺胺喹恶啉、磺胺氯吡嗪和多西环素外，所有在0.5（1或1.5）、5和50 ng/mL加标的分析物回收率在60.0 - 98.0%范围内，低浓度水平相对标准偏差低于25%，中浓度为20%，高浓度为15%。分析物的决策限和检测能力分别为0.005至0.5 μg/kg和0.02至1.5 μg/kg。该方法针对生菜基质进行开发和验证，从包括白萝卜、大白菜、黄瓜、四季豆和青椒在内的其他五种蔬菜中也获得了较高的回收率。评估了不同蔬菜的基质效应，观察到26种分析物中的大多数存在信号抑制效应。最后，该方法应用于从当地养猪场附近农业地区采集的实际样品分析，蔬菜受抗菌药物残留污染的现象令人担忧。
