聚合物整体柱微萃取-高效液相色谱法检测鸡蛋中的磺胺嘧啶和磺胺二甲嘧啶残留

建立了鸡蛋中磺胺嘧啶和磺胺二甲嘧啶残留量的聚合物整体柱微萃取和高效液相色谱检测方法。以聚(甲基丙烯酸-乙二醇二甲基丙烯酸酯)毛细管整体柱作为萃取装置。为了得到较高的萃取效率,优化了影响萃取效率的参数(萃取流速、萃取体积、样品基质pH值)。样品经过匀浆、乙醇提取、磷酸盐缓冲溶液稀释、离心等步骤后直接进行萃取。鸡蛋中磺胺嘧啶和磺胺二甲嘧啶的检出限分别为11.2 ng/g和8.8 ng/g,在50～5000 ng/g的浓度范围内具有良好的线性关系。加标回收率大于65%,日内、日间测定的相对标准偏差不高于8.2%。结果表明,方法简单、快速、灵敏度高,适用于鸡蛋中磺胺嘧啶和磺胺二甲嘧啶的常规分析。

Monitoring Sulfadiazine and Sulfamethazine Residues in Eggs Using Polymer Monolith Microextraction Coupled with High Performance Liquid Chromatography

The method for the quantitative monitoring of sulfadiazine and sulfamethazine residues in eggs was established by coupling polymer monolith microextraction (PMME) with high performance liquid chromatography and ultra-violet detection (HPLC/UV). The PMME is an effective sample preparation technique, which has been developed on the basis of in-tube solid-phase microextraction. A poly (methacrylic acid-ethylene glycol dimethacrylate) monolithic capillary column was selected as an extraction device. To obtain the optimum extraction efficiency, several parameters related to PMME, including extraction flow-rate, extraction volume, and pH value of the sample matrix were investigated. The sample solution can be directly injected into the device for extraction after simple extraction with ethanol, dilution with phosphate buffer solution, and centrifugation. Because of the high extraction capacity of the monolith column, low detection limits (S/N=3) (8.8 ng/g for sulfamethazine and 11.2 ng/g for sulfadiazine) and quantification limits (S/N=10) (29.3 ng/g for sulfamethazine and 37.5 ng/g for sulfadiazine) were obtained. The method showed good linearity ranging from 50 to 5000 ng/g. Excellent reproducibility of the method was found by intraday and interday precisions, yielding the relative standard deviations of < or = 7.6% and < or = 8.2%, respectively. Recoveries for them were higher than 65%. Compared with the standard methods used in China, improved results were obtained using this method. The proposed method was proved to be simple, rapid, sensitive, and competent in monitoring sulfadiazine and sulfamethazine residues in eggs.