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

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4~48μmol·L-1,检出限(3S/N)为0.20μmol·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。

Basic OrangeⅡ imprinted polymers(BO-MIPs)were prepared using Basic OrangeⅡ 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 OrangeⅡ in mixture could be specifically recognized by BO-MIPs.Linearity range of Basic OrangeⅡ found was 4-48μmol·L-1 with detection limit(3S/N)of 0.20μmol·L-1.Selectivity adsorption and recovery of Basic Orange Ⅱ on BO-MIPs were in the ranges of 94.5%-100% and93.0%-99.4%respectively,with RSD(n=5)in the range of 3.2%-5.4%.