分子印迹固相萃取-超高效液相色谱法测定河水中的碱性橙Ⅱ
Separation and Determination of Basic Orange Ⅱ in River Water by Molecularly Imprinted Polymers Solid Phase Extraction Coupled with UHPLC
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摘要: 以碱性橙Ⅱ为模板分子,α-甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用沉淀聚合法合成分子印迹聚合物(BO-MIPs)和不添加模板的非印迹聚合物(MNIPs)。上述聚合物通过扫描电镜、傅里叶红外光谱、X射线衍射法进行结构表征及等温吸附和动力学吸附试验,结果表明:与MNIPs相比,BO-MIPs对模板分子具有明显的特异性吸附作用。在此基础上,利用分子印迹固相萃取结合超高效液相色谱法对等浓度混合的6种结构相似的偶氮色素溶液进行分子识别性研究,发现BO-MIPs对碱性橙Ⅱ具有专一识别性。碱性橙Ⅱ线性范围为4~48 μmol·L-1,检出限(3S/N)为0.20 μmol·L-1。BO-MIPs对碱性橙Ⅱ的选择吸收率和回收率分别在94.5%~100%和93.0%~99.4%之间,测定值的相对标准偏差(n=5)在3.2%~5.4%之间。Abstract: Basic Orange Ⅱ imprinted polymers (BO-MIPs) were prepared using Basic Orange Ⅱ as template molecule, α-methacrylic acid as the functional monomer and ethylene dimethacrylate (EDMA) as the cross-linker by precipitation polymerization. In addition, nonimprinted polymers (MNIPs) were synthesized in the absence of any template molecule. The polymers were fully characterized by scanning electron microscope, Fourier transform infrared spectrometry and X-ray powder diffraction analysis, the isothermal absorption and kinetics absorption. The results showed that the BO-MIPs possessed higher specific adsorptivity toward the template molecule compared with that of MNIPs. The selectivity recognition for six structurally similar analytes was determined by BO-MIPs with UHPLC. The results also showed that Basic Orange Ⅱ in mixture could be specifically recognized by BO-MIPs. Linearity range of Basic Orange Ⅱ found was 4-48 μmol·L-1 with detection limit (3S/N) of 0.20 μmol·L-1. Selectivity adsorption and recovery of Basic Orange Ⅱ on BO-MIPs were in the ranges of 94.5%-100% and 93.0%-99.4% respectively, with RSD (n=5) in the range of 3.2%-5.4%.