吡啶离子液体双水相-高效液相色谱法同时测定牛奶中3种喹诺酮药物残留

Simultaneous Determination of Three Quionlones Residues in Milk by Pyridinium Ionic Liquid-based Aqueous Two-phase Systems Coupled with High Performance Liquid Chromatography

建立了吡啶离子液体双水相-高效液相色谱同时测定牛奶中嗯喹酸、萘啶酸及氟甲喹3种喹诺酮药物残留的方法．牛奶样品经氯化钠和磷酸混合溶液提取后，采用吡啶离子液体N-乙基-2-甲基吡啶溴化盐（[EMPy]Br）和K2HPO4形成的双水相体系萃取富集，以0．1％磷酸水溶液-乙腈为流动相，梯度洗脱，紫外检测．该方法对嗯喹酸、萘啶酸和氟甲喹测定的线性范围分别为0．3—15，0．5～20和0．5～25μg/mL，相关系数（r）均大于0．9997，3种药物的检出限在8～10μg/kg之间．对不同加标浓度的牛奶样品测定，绝对回收率均在86．4％．94．8％范围内，相对标准偏差为3．6％-8．3％．该方法对牛奶中喹诺酮药物残留的检测具有简单、快速、环保和灵敏度高等优点．

A method was developed for the analysis of three quinolones （ oxolinic acid, nalidix acid and flumequine） in milk by pyridinium ionic liquid-based aqueous two-phase systems coupled with high performance liquid chromatography. Milk samples were extracted with the mixed solutions consisting of sodium chloride and phosphoric acid. Then extracts were enriched by aqueous two-phase systems composed of the ionic liquid pyri- dine N-ethyl -2-methyl-pyridine bromide salt（ [ EMPy] Br） and K2HPO4. The separation of the analytes was achieved via 0. 1% phosphoric acid and acetonitrile with gradient elution under UV detection. The linear ranges are 0. 3-15μg/mL for oxolinic acid, 0. 5-20 μg/mL for nalidixic acid and 0. 5-25 μg/mL for flumequine. The correlation coefficient（r） is more than 0. 9997. The limits of detection are 8-10 μg/kg. Based on detecting spiked quinolones concentrations in milk samples, the absolute recoveries ranged from 86.4% to 94. 8% with relative standard deviation from 3.6% to 8.3%. The proposed method of determinating quinolones residues in milk is simple, rapid, friendly to environment and high sensitive.