基于涡流色谱技术的在线固相萃取/高效液相色谱-荧光检测法结合在线稀释快速测定牛奶中5种氟喹诺酮抗生素残留

Rapid Determination of Five Fluoroquinolones Antibiotic Residues in Milk by Turboflow Chromatography-based Online SPE /HPLC- Fluorescence Detection Combined with Online-dilution

建立了牛奶中环丙沙星、达氟沙星、恩诺沙星、沙拉沙星和二氟沙星残留量的快速测定方法。牛奶样品经0.2％三氯乙酸-乙腈（90：10）沉淀蛋白后，直接进样分析，采用涡流色谱柱作为在线固相萃取柱，通过双梯度液相色谱的左泵结合大体积进样方式对目标分析物进行富集和净化，利用在线100μL定量环中的强洗脱溶剂快速转移目标分析物，并以右泵作为在线稀释泵和分析泵，通过柱头浓集作用改善分离效果。通过荧光检测，方法检出限为0.01-0.13μg/L，远低于欧盟规定限量，且在一定浓度范围内，方法的线性较好，加标回收率为75.9％-95.7％。该方法简便、快速、灵敏度较高，适用于牛奶样品中环丙沙星等5种兽药残留的快速检测。

A rapid method was established for determination of five fluoroquinolones antibiotic resi-dues in milk. Sample solution was injected after protein precipitating with 0. 2% trichloroacetic acid-acetonitrile（90 ： 10）. Turboflow column was used as SPE column to enrich sample through large volume injection and cleanup with left pump of dual gradient LC. Strong solvent stored in 100 micro-liter loop was used to transfer the analyte which was diluted with right pump of DGLC in online mode. Then peak shape and resolution were improved by peak refocusing effect. The limits of detection （ LODs）were between 0. 01 μg/L and 0. 13 μg/L by fluorescence detection,which were far below the maximum residue levels for milk set by the EU regulations. The linearity of this method was good in the certain concentration range. The mean recoveries were in the range of 75. 9% - 95. 7% . The results indicated that this method is simple,rapid and sensitive,and is suitable for the determination of five fluoroquinolones antibiotic residues in milk.