Nemulenzi Olga, Mhaka Byron, Cukrowska Ewa, Ramström Olof, Tutu Hlanganani, Chimuka Luke
School of Chemistry, University of the Witwatersrand, WITS, Johannesburg, South Africa.
J Sep Sci. 2009 Jun;32(11):1941-8. doi: 10.1002/jssc.200800659.
The potential of combination of liquid membranes (microporous membrane liquid-liquid extraction) and molecularly imprinted polymers (MIPs) was performed using 17beta-estradiol (E2) as model compound. The model compound was extracted from aqueous sample through a hydrophobic porous membrane that was impregnated with hexane/ethyl acetate (3:2), which also formed part of the acceptor phase. In the acceptor phase, the compound was bound onto MIP particles that were also part of the organic phase. The potential of such combination was optimised for the type and amount of MIP particles in the organic acceptor phase, the extraction time, and the type of organic acceptor solvent. Ultrasound assisted binding of E2 onto MIP particles was also investigated. MIPs prepared by precipitation polymerization were found to be superior to those prepared by bulk polymerization. Increase in the extraction time and the amount of MIP particles in the acceptor phase led to more E2 binding onto the MIP particles. Hexane/ethyl acetate (3:2) as an organic acceptor was found to give higher E2 binding onto MIP particles compared to toluene, diethyl ether, and hexane. Ultrasound was furthermore found to increase the binding of E2 onto MIP particles. The selectivity of the technique was demonstrated by extracting wastewater and where clean chromatograms were obtained compared to liquid membrane extractions (SLMs) alone.
以17β-雌二醇（E2）为模型化合物，研究了液膜（微孔膜液-液萃取）与分子印迹聚合物（MIPs）结合的潜力。模型化合物通过浸渍有己烷/乙酸乙酯（3:2）的疏水多孔膜从水样中萃取，该混合物也是接受相的一部分。在接受相中，化合物与同样作为有机相一部分的MIP颗粒结合。针对有机接受相中MIP颗粒的类型和数量、萃取时间以及有机接受溶剂的类型，对这种结合的潜力进行了优化。还研究了超声辅助E2与MIP颗粒的结合。发现沉淀聚合法制备的MIPs优于本体聚合法制备的MIPs。萃取时间的增加和接受相中MIP颗粒数量的增加导致更多的E2与MIP颗粒结合。与甲苯、二乙醚和己烷相比，发现己烷/乙酸乙酯（3:2）作为有机接受体时，E2与MIP颗粒的结合更高。此外，发现超声可增加E2与MIP颗粒的结合。通过萃取废水证明了该技术的选择性，与单独的液膜萃取（支撑液膜）相比，获得了干净的色谱图。
