分子印迹固相萃取/高效液相色谱法检测黄瓜中灭蝇胺

摘要

以灭蝇胺为模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,甲苯和异辛烷为二元致孔剂,采用低温光引发、本体聚合法制备了灭蝇胺的分子印迹聚合物.通过平衡吸附实验、扫描电镜、红外光谱以及压汞仪等多种手段对制备的印迹和非印迹聚合物进行了测定与表征,结果表明所制备的印迹聚合物对模板分子具有明显的特异性吸附作用.Scatchard分析证明灭蝇胺分子印迹聚合物对灭蝇胺分子的吸附存在两类不同结合位点,最大表观结合量(Qmax)和平衡解离常数(Kd)分别为Qmax1=1.19μmol/g,Kd1=1.31 μmol/L；Qmax2 =2.46 μmol/g,Kd2=4.84 μmol/L.用该聚合物制备的灭蝇胺分子印迹固相萃取柱处理样品,结合高效液相色谱法可快速有效地检测黄瓜样品中的灭蝇胺,线性范围为0.1～10 mg/L(r =0.9991),检出限(S/N=3)为0.05 mg/L.该方法快速简便,效果优于商品化的固相萃取柱.%Cyromazine moleeularly imprinted polymers ( MIPs) were synthesized by UV photo -initiation and bulk polymerization method at low temperature, using cyromazine as template molecule, methacrylic acid(MAA) as functional monomer, ethylene dimethacrylate(EDMA) as cross-linker, toluene and isooctane as binary porogen. Comparative determination and characterization of the prepared M1P and NIP were carried out by equilibrium adsorption experiment, scanning electron microscope (SEM) , infrared absorption (IR) and mercury analyzer (MA). The results showed that the MIPs possessed the specific adsorptivity toward the template molecule. Scatchard plot's analysis revealed that the apparent maximum binding capacity and the dissociation contents were as the follows; Qmax1 =1. 19 μmol/g, Kdl =1.31 μmol/L; Qmax2=2.46 μmol/g, Kd2=4.84 imol/L. It was demonstrated that the proposed MI - SPE/HPLC method could be successfully applied in the determination of cyromazine in cucumber sample. A linear calibration curve was obtained in the concentration range of 0. 1 - 10 mg/L(r =0. 999 1) with a detection limit of 0. 05 mg/L. The established method was simple and rapid , and had a better effect than commercial SPE column.