凝胶渗透色谱/液相色谱串联质谱法测定畜禽及水产品组织中头孢喹肟的残留量

建立了牛肉、猪肉、鸡肉、鱼肉、泥鳅肉等动物组织中头孢喹肟残留的高效液相色谱串联质谱检测方法。样品经乙腈-水(体积比4∶1)提取、Sephadex LH-20凝胶柱(16 mm i.d.×320 mm)净化;采用CAP-CELL PAK MG C18(100 mm×2.0 mm,3μm)色谱柱,以0.1%甲酸-甲醇为流动相,0.2 mL/min梯度洗脱,电喷雾正离子模式电离,选择反应监测(SRM)模式测定。检测离子对为m/z 529.1/134.2、529.1/396.1、529.1/125.1,其中m/z 529.1/134.2为定量离子对。在优化实验条件下,头孢喹肟在5.0～200μg/L范围内线性良好,相关系数(r)为0.999 1,检出限(LOD)为1.0μg/kg,定量下限(LOQ)为3.0μg/kg;在3.0、10、50、100μg/kg 4个加标水平下的平均回收率为75%～105%,相对标准偏差(RSD)为2.4%～11.9%。该方法净化效果理想、重复性好、灵敏度高,可满足动物组织中头孢喹肟药物残留的检测要求。

Determination of Cefquinome Residues in Tissues of Livestock and Aquatic Products by High Performance Liquid Chromatography Tandem Mass Spectrometry with Gel Permeation Chromatography

A high performance liquid chromatography-tandem mass spectrometric(HPLC-MS/MS) method was developed for the determination of cefquinome residues in animal tissues,such as beef,pork,chicken,fish and loach.The sample was extracted with acetonitrile-water(4∶1) and cleaned up with Sephadex LH-20 gel column(16 mm i.d.×320 mm).The separation of cefquinome was performed on a CAPCELL PAK MG C18(100 mm ×2.0 mm,3 μm) column using a mobile phase of 0.1% formic acid-methanol by gradient elution at a flow rate of 0.2 mL/min.The electrospray was operated in the positive ionization mode and cefquinome was identified under selective reaction monitoring(SRM) mode.The ion pairs,m/z 529.1/134.2,529.1/396.1 and 529.1/125.1 were selected as the qualitative ion pairs,and m/z 529.1/134.2 was used as the quantitative ion pair.Under the optimal conditions,the calibration curve showed a good linearity in the range of 5.0-200 μg/L for cefquinome with a correlation coefficient of 0.999 1.The limit of detection(LOD,S/N≥3) for cefquinome was 1.0 μg/kg and the limit of quantitation(LOQ,S/N≥10) was 3.0 μg/kg.The recoveries of cefquinome at four spiked concentration levles of 3.0,10,50 and 100 μg/kg ranged from 75% to 105%,with relative standard deviations(RSDs,n=6) of 2.4%-11.9%.With the advantages of high cleanup effectiveness,good reproducibility and high sensitivity,the method could meet the requirements for the determination of cefquinome residues in animal tissues.