液相色谱-质谱联用检测牛奶中氟喹诺酮类药物残留的确证方法

 【目的】建立牛奶中诺氟沙星、氧氟沙星、麻保沙星、培氟沙星、环丙沙星、洛美沙星、达氟沙星、恩诺沙星、沙拉沙星、二氟沙星等10种氟喹诺酮类药物残留检测的液相色谱-大气压化学电离-离子阱质谱确证方法。【方法】牛奶经三氯乙酸和乙腈沉淀蛋白、聚合物反相Strata-X固相萃取柱净化、ODS2 分离后，用大气压化学电离-离子阱质谱测定。【结果】对诺氟沙星、培氟沙星、环丙沙星、恩诺沙星和沙拉沙星等5种药物进行了定量方法学验证：在1.0～100.0 ng?ml-1范围内线性良好（r>0.99）；以1.0、10.0、100.0 ng?ml-1浓度水平的添加回收率为60.6%～101.0%，日内变异系数≤17.5%，日间变异系数≤22.1%；检测限为0.2～0.8 ng?ml-1，定量限为0.8～2.8 ng?ml-1。【结论】此方法为一种检测氟喹诺酮类药物在牛奶中残留的高通量确证分析方法。

Confirmation of Fluoroquinolone Residues in Milk by Liquid Chromatography-tandem Mass Spectrometry

A confirmation method is developed for determination of 10 fluoroquinolones (FQs), marbofloxacin(MAR), norfloxacin (NOR), ofloxacin (OFL), pefloxacin (PEF), ciprofloxacin (CIP), lomefloxacin (LOM), danofloxacin (DAN), enrofloxacin (ENR), sarafloxacin (SAR) and difloxacin (DIF) in milk using ion-trap-APCI liquid chromatography-tandem mass spectrometry. Milk was precipitated by trichloroacetic acid and acetonitrile and then the extracts were purified onto reverse phase polymer Strata-X cartridges. The determination was achieved by liquid chromatography using an ODS2 analytical column with ion-trap-APCI tandem mass spectrometry. The procedure was validated by spiking 5 FQs (NOR, CIP, PEF, ENR, and SAR) into a blank milk at seven different levels (5.0、10.0、20.0、50.0、100.0、200.0、500.0 ng/mL) and linearity (r2>0.99), accuracy (recovery=48.8%～110.0%), precision (RSD≤18.5%) and sensitivity (LOD=0.2～0.8 ng/mL, LOQ= 1.0～5.0 ng/mL) were checked. The results showed that this method was a high throughputing procedure for confirmation of the FQs residues in milk.