将聚(甲基丙烯酸-乙二醇二甲基丙烯酸酯)(poly(MAA-co-EDMA))聚合物原位聚合于玻璃内插管外表面上,得到一种多孔聚合物涂层;将其作为搅拌棒吸附萃取的萃取介质,考察了其对磺胺类药物的萃取性能;最后将其与高效液相色谱-电喷雾质谱(HPLC-ESI-MS)联用,建立了一种牛奶中4种磺胺类药物的检测方法。在最佳条件下,牛奶中4种磺胺类药物的检出限(S/N=3)和定量限(S/N=10)分别为0.11~0.52μg/L和0.35~1.72μg/L。在1~500μg/L的范围内峰面积与质量浓度具有良好的线性关系,日内、日间测定的相对标准偏差不高于11.3%。结果表明,该方法简便、灵敏度高且成本低,适合于牛奶中磺胺类药物的检测。
A poly(methacrylic acid-co-ethylene dimethacrylate) polymer(poly(MAA-co-EDMA)) was prepared via in-situ polymerization on the outside surface of vial glass insert and used as stir rod sorptive extraction(SRSE) coating.The extraction performance of the polymer coating toward four sulfonamides(SAs) was investigated.The effects of several parameters to SRSE,such as the pH value,inorganic salt and organic phase concentrations of the sample matrix,were investigated.It demonstrated that the sulfonamides were captured on the poly(MAA-co-EDMA) coating mainly through cation-exchange and hydrophobic interactions.A novel approach is presented for the determination of four sulfonamide antibacterial residues in milk samples by coupling SRSE to liquid chromatography and electrospray ionization mass spectrometry(SRSE/LC-ESI-MS).In this method,the detection limits(S/N=3) of 0.11-0.52 μg/L and quantification limits(S/N=10) of 0.35-1.72 μg/L were obtained.The method showed good linearity in the range of 1-500 μg/L.Good method reproducibility was also found by intra-and inter-day precisions,yielding the relative standard deviations(RSDs) less than 11.3%.The results demonstrated that the proposed method is simple,sensitive,low cost and suitable for the determination of sulfonamides in milk samples.