在线净化-液质联用法测定鸡肉中8种喹诺酮类兽药残留

Determination of Eight Quinolones Residues in Chicken by Online Clean-up-liquid Chromatography- tandem Mass Spectrometry

关键词:  在线净化  液相色谱-串联质谱  喹诺酮类  鸡肉

Key words:  online clean-up  LC-MS/MS  quinolones  chicken

摘要:

目的 建立三柱二维在线净化-液相色谱-串联质谱测定鸡肉中诺氟沙星、依诺沙星、环丙沙星、洛美沙星、氧氟沙星、马波沙星、沙氟沙星和奥比沙星8种喹诺酮类兽药残留的检测方法。方法 利用凝胶色谱的体积排阻原理，使大分子的基质干扰物质不经保留直接洗脱，小分子的目标化合物在色谱柱上保留时间较长，实现目标化合物与基质的分离，去除基质干扰后，在二维色谱系统进行切换，将目标化合物保留在富集柱上，当目标物完全转移到富集柱后，二维色谱再次切换至初始状态，同时目标物在第二维色谱柱上进行分离分析。鸡肉样品经乙腈提取和浓缩后，用二维液相色谱质谱联用技术在多反应监测模式下测定其中8种喹诺酮类兽药残留。结果 8种喹诺酮类兽药的检出限为0.2 μg·kg^–1。8种喹诺酮类兽药在4.0~100.0 ng·mL^–1内具有较好的线性关系，相关系数均>；0.991。回收率为92.5%~109.5%，相对标准偏差为1.1%~9.2%。对67批市售鸡肉进行检测，氧氟沙星检出2批次，与国家标准检测方法检测结果一致，偏差均<5%。结论 本方法简便、快速、准确，适用于鸡肉样品中8种喹诺酮类兽药残留的检测。

Abstract:

OBJECTIVE To establish a method based on two-dimensional online cleanup mode with three columns coupled to liquid chromatography-tandem mass spectrometry for the determination of eight quinolones residues(norfloxacin, enoxacin, ciprofloxacin, lomefloxacin, ofloxacin, mapofloxacin, shafofloxacin and obifloxacin) in chicken.METHODS Used the principle of size exclusion chromatography to make the matrix interfering substances directly being eluted without reservation.The target compounds of small molecules were retained for longer time on the chromatographic column.So the separation of target compounds and matrix was realized in this method.After excluding the interference of matrix, the target compounds were retained on the enriched column by the switching the valve.After the column collection, the two-dimensional chromatography wash switched to the initial state, and the target substances were separated and analyzed on the second two-dimensional column.After extracted with acetonitrile and an automated sample cleanup procedure with aqueous gel column, the eight quinolones residues in chicken samples were precisely determined in multiple reaction monitoring(MRM) mode by two-dimensional liquid chromatography-tandem mass spectrometry(LC-MS/MS).RESULTS The limit of quantification for the eight quinolones was 0.2 μg·kg^–1, the method produced linear results for eight guinolones from 4.0 to 100.0 ng∙mL^–1 with a linearity >0.991.The recoveries was in the range of 92.5%-109.5% with the relative standard deviations between 1.1% and 9.2%.Ofloxacin was detected in two batches of chicken among 67 batches, which were consistent with the results of the national standard test method, and the deviations were <5%.CONCLUSION This method is simple, rapid, accurate, and suitable for the simultaneous determination of the eight quinolones in chicken.