新型固相微萃取-高效液相色谱测定牛奶中4种磺胺类药物残留

A Novel Solid-phase Microextraction Method Coupled with HPLC for Determination of Four Sulfonamides in Milk Samples

采用原位聚合法在经修饰的不锈钢丝表面键合聚(甲基丙烯酸-乙二醇二甲基丙烯酸酯)材料,并以之作为固相微萃取纤维涂层,调节样品基质至pH 5,在30℃萃取50 min,在乙腈和0.1%甲酸(20∶80,V/V)中解吸12 min,同时与高效液相色谱联用,建立了牛奶中4种典型磺胺类药物残留的分析方法。实验结果表明,本方法的日内(n=3)和日间(n=5)精密度(RSD)分别小于6.1%和2.8%,平均加标回收率在68.2%～100.3%之间;涂层的制备重现性和实验重现性较好(RSD<5.82%,n=4),4种磺胺类化合物的线性范围为10～500μg/L,线性相关系数r>0.99,检出限在2～10μg/L之间。

An in-situ polymerization method was used in the preparation of a noval solid-phase microextraction（SPME） coating,where poly（methacrylic acid-ethylene glycol dimethacrylate（poly（MAA-EGDMA）） was directly bonded to the surface of polydopamine-modified stainless steel wire.Coupled to high performance liquid chromatography,the prepared coating was applied in the extraction and determination of four typical sulfonamides in milk samples.The effects of several impacting parameters such as pH,temperature,extraction time and desorption time on the extraction process were investigated.With sample pH value at 5,several types of sulfonamides were extracted from milk samples at 30 ℃ for 50 min by the as-prepared fiber and then eluted with acetonitrile-0.1% formic acid（20 ∶ 80,V/V） for 12 min before analyzed by high performance liquid chromatography.As a result,the intra-day（n=3） and inter-day（n=5） relative standard deviations of this method were lower than 6.1% and 2.8%,respectively;and the recoveries of four sulfonamides were ranged from 68.2% to 100.3%;the repeatabilities（n=4） of fiber preparation and experiments were below 5.8%;linear relationships for four sulfonamides were obtained with r〉0.99（10-500 μg/L）;limits of detection ranged from 2 to 10 μg/L after optimization of all extraction steps.