高效液相色谱荧光检测法测定牛奶中3种氟喹诺酮残留研究

Determination of 3 fluoroquinolone residues in milk by HPLC-FLD

目的：建立牛奶中环丙沙星、双氟沙星和沙拉沙星3种氟喹诺酮残留的高效液相色谱荧光检测方法。方法：样品经磷酸盐缓冲液稀释、提取后,用Waters Oasis HLB固相萃取小柱进行浓缩、净化,Extend-C18柱（250 mm×4.6 mm×5μm）分离;流速：0.8 ml/min;柱温：35℃;流动相：甲醇＋乙腈＋0.2%甲酸（15＋15＋70）;荧光检测波长：λex为275 nm;λem为445 nm。结果：在0.1-5.0 mg/L范围内三种被测化合物均呈良好线性关系,方法回收率在90.0%-102.0%之间,相对标准偏差为4.1%-10.0%,最低检出限环丙沙星、双氟沙星和沙拉沙星分别为0.02、0.015和0.02 mg/L。结论：所建方法简便、灵敏、重现性好、干扰少、特异性好,能满足牛奶中三种目标化合物的检测要求。

Objective：To establish a HPLC-FLD method for simultaneous determination of 3 fluoroquinolones in milk.Methods：After fluoroquinolones in milk were diluted and extracted by phosphate buffer,the sample was concentrated and cleaned by solid phase extraction using Oasis HLB cartridges and the sample was separated on a Extend-C18 column（250 mm×4.6 mm×5 μm）with FLD at λex 275 nm,λem 445 nm by using the mobile phase consisting of CH3OH＋CH3CN＋0.2% HCOOH（15＋15＋70）.The flow rate was 0.8 ml/min and the column temperature was controlled at 35℃.Results：Calibration curves were linear within the range of 0.1～5.0 mg/L and the limits of quantification were 0.02,0.015 and 0.02 mg/L for ciprofloxacin,difloxacin and sarafcoxacin.The extraction recoveries were between 90.0%～102.0%,the RSD 4.1%-10.0%.Conclusion：This method is simple,sensitive,accurate and of good specificity for the determination of 3 trace fluoroquinolones in milk.