混合胶束浊点萃取结合磁分散固相微萃取测定苏丹橙G

Determination of Sudan orange G by mixed micelle cloud point extraction combined with magnetic dispersive μ-solid phase extraction

通过混合胶束浊点萃取（MM-CPE）结合磁分散固相微萃取（MD-μ-SPE）并使用高效液相色谱法（HPLC）测定苏丹橙G。混合胶束阴离子表面活性剂十二烷基硫酸钠和非离子表面活性剂聚氧乙烯（7.5）壬基苯基醚为萃取剂,Fe3O4@SiO2磁性纳米粒子为吸附剂。考察了表面活性剂种类、NaCl用量、溶液pH、温度、萃取时间、解吸剂、磁性材料用量对苏丹橙G萃取率的影响。实验结果表明,在较佳条件下,样品在5-800 ng/m L的范围内线性关系良好,线性回归系数为0.9995,检测限为0.64 ng/mL,番茄酱的加标回收率为98.5%,相对标准偏差为2.5%（n=5）。

Mixed micelle cloud point extraction （MM-CPE） combined with magnetic dispersive μ-solid phase extraction （MD-μ-SPE） has been developed for the extraction of Sudan orange G prior to high performance liquid chromatography （HPLC） analysis. A mixed micelle containing anionic surfactant sodium dodecyl sulfate and non-ionic polyoxyethylene （7.5） nonylphenylether was used as the extraction solvent in MM-CPE, and Fe3O4@SiO2 magnetic nanoparticles were used as the adsorbent in MD-μ-SPE. The method was based on the following principle： Sudan orange G was extracted into surfactant-rich phase through MM-CPE first; magnetic materials, which was easily separated from the aqueous phase under magnetic field, were used to retrieve the surfactant-rich phase. The effect of some influencing factors in this method, such as surfactant type, concentration of NaCX, pH, temperature and time of equilibration, desorption solvent and amounts of magnetic material, on the final results were investigated. Under the optimal conditions, the method presented good linearity （r2 = 0.999 5） in the range of 5-- 800 ng/mL （concentration of Suan orange G）. The detection limit was 0.64 ng/mL. The method was successfully applied to the determination of Sudan orange G in tomato sauce and good recovery rates （98.5%） with relative standard deviation of below 2.5% （n=5） were achieved.