氘代同位素内标液相色谱-串联质谱法测定蜂蜜中环丙沙星残留

Determination of ciprofloxacin in honey by liquid chromatography coupled with mass spectrometry using deuterated isotope internal standard

目的：建立蜂蜜中环丙沙星的氘代同位素内标液相色谱-串联质谱测定方法。方法：蜂蜜样品经磷酸盐缓冲液溶解和稀释后,加入适量环丙沙星-d8同位素内标溶液,采用Waters Oasis MAX小柱进行净化,在Cloversil-C18柱上,采用乙腈＋0.05%三氟醋酸（25＋75）为流动相,应用高效液相色谱/电喷雾质谱多离子反应监测模式（MRM）测定,内标法定量。结果：蜂蜜中环丙沙星浓度在0.1～50.0μg/kg范围内呈良好线性关系,方法回收率在95.0%～102.0%之间,平均回收率为98.3%,RSD小于4.1%,定量检出限为0.1μg/kg。结论：本方法简便、灵敏、重现性好、干扰少、特异性好,能满足蜂蜜中环丙沙星痕量残留的检测要求。

Objective：To establish a sensitive method for the determination of ciprofloxacin in honey by liquid chromatography tandem mass spectrometry（LC-MS/MS） using deuterated isotope internal standard.Methods：After honey sample was dissolved and diluted by phosphate buffer solution,and spiked with deuterated isotope internal standard（ciprofloxacin-d8）,a solid-phase extraction（SPE） cleaning pretreatment was performed using OasisMAX cartridges.The sample was separated on a Cloversil-C18 column（150 mm × 4.6 mm i.d.,5 μm） by using the mobile phase consisting of CH3CN＋0.05%CF3COOH（25＋75）.Detection was carried out by LC-MS/MS using an electrospray ionization interface in the multiple reaction monitoring mode（MRM）.Results：Calibration curve was linear within the range of 0.1～50.0 μg/kg and the limit of quantification was 0.1 μg/kg.The extraction recovery was between 95.0%～102.0% and the average recovery was 98.3%,the RSD was less than 4.1%.Conclusion：This method is simple,sensitive,accurate,of little interference and good specificity for the satisfactory determination of trace ciprofloxacin residue in honey.