头孢噻呋及去呋喃甲酰基头孢噻呋的四极杆轨道阱串联质谱分析及其在肉鸡体内的残留规律研究

建立了头孢噻呋及其主要代谢物去呋喃甲酰基头孢噻呋残留的超高效液相色谱-四极杆轨道阱串联质谱（UHPLC-Q-Orbitrap MS）分析方法。选用Kinetex F5 100A色谱柱（50 mm×3.0 mm×2.6 μm）分离，在Q-Exactive高分辨质谱Full MS/dd-MS²扫描模式下采集数据进行定性定量分析。两种目标物在3种基质中相应浓度范围内的线性关系良好，相关系数r²均大于0.990，回收率为83.2%~129.7%，RSD均小于15%。通过对鸡体内头孢噻呋及其代谢物残留规律的分析表明，给药后，鸡胸肉中头孢噻呋和去呋喃甲酰基头孢噻呋均可检出，且消除时间均为12~24 h；鸡肝、鸡肾中头孢噻呋可在0.5 h内迅速代谢为去呋喃甲酰基头孢噻呋，鸡肝和鸡肾中去呋喃甲酰基头孢噻呋的消除时间分别为48~72 h和72~120 h。本研究可为保障动物源性食品安全以及鸡体内头孢噻呋最大残留限量标准和休药期的制订提供理论和实践依据。

Determination of Ceftiofur & Desfuroyl Ceftiofur Residue and the Elimination Analysis in Chicken Using Liquid Chromatography Quadrupole-Orbitrap Hybrid Mass Spectrometry

A method of liquid chromatography quadrupole-Orbitrap hybrid mass spectrometry was developed and validated for the determination of ceftiofur and desfuroylceftiofur in chicken. The Kinetex F5 100A column (50 mm×3.0 mm×2.6 μm) was used during the separation of ceftiofur and desfuroylceftiofur. Full MS/dd-MS² mode was chosen for data acquisition, which showed good form in sample qualitative and quantitative analysis. The fragmentation pathways of ceftiofur and desfuroylceftiofur were clarified based on the results of high-accuracy mass spectrometry. During analysis of three types of matrixes (chicken, liver and kidney), correlation coefficients of linear calibration curves of ceftiofur and desfuroylceftiofur are over 0.990 at the corresponding concentration ranges of 2-200 μg/kg. The average recoveries of ceftiofur and desfuroylceftiofur range from 83.2% to 129.7% with the inter-day relative standard deviation (RSD) less than 15% in spiked samples at three levels. Besides, the elimination of ceftiofur in hens was studied. Ceftiofur was injected in hens’ muscle once a day for three consecutive days. The residue can not be detected in chicken breast after 12 h, while ceftiofur and desfuroylceftiofur can be detected in chicken breast simultaneously during 12 h. The metabolism of ceftiofur in hens’ liver and kidney is fast. It can totally metabolize to desfuroylceftiofur during less than 0.5 h. The residue of desfuroylceftiofur in hens’ liver can not be detected after 48 h, while the residue in kidney can not be detected after 72 h. This research can provide a basis for reference for the future development of long plagued quality and safety issues.