A Surface Molecularly Imprinted Polymer for Selective Extraction and Liquid Chromatographic Determination of 4-Methylimidazole in Environmental Samples

摘要

A newly designed surface molecularly imprinted polymer (MIP) was developed using 4-methylimidazole as the template and ethylenediamine-poly (styrene-divinylbenzene) particles as the support material. The resulting MIP material was characterized with scanning electron microscopy, infrared spectrum, surface area, pore-size and thermal property measurements. Static adsorption, solid-phase extraction (SPE) and high-performance liquid chromatography were combined to study the adsorption characteristics and selective recognition performance of the polymer for 4-methylimidazole and its structural analogues. It was shown that the maximum binding capacities of 4-methylimidazole on the MIP and the non-imprinted polymer (NIP) were 416 and 227 μmol g~(-1), respectively. The binding process could be described by pseudo-second-order kinetics, and the adsorption equilibrium was achieved in 40 minutes. Compared with the corresponding NIP, the MIP exhibited much higher adsorption performance and selectivity for the template. After the separation of a mixture of 4-methylimidazole, benzimidazole and nitrophenol on the MIP-SPE and the NIP-SPE columns, the recoveries of 4-methylimidazole on the MIP-SPE and NIP-SPE columns were 96-102% and 34-39%, respectively, whereas those of benzimidazole and nitrophenol were below 19% on the two columns. In addition, more than 99% of 4-methylimidazole could be obtained on the MIP-SPE column from water and soil samples.