Preparation And Adsorption Property Of Magnetic Molecularly Imprinted Polymers For Selective Recognizing Estradiol

Estradiol?E2?is one of the most potent endocrine disruptors known to have estrogenic activity.As one of natural estrogens,estradiol is widely present in the natural environment.Many papers have reported that trace concentrations of estradiol can have serious effects on the ecological environment and human health.Therefore,in order to detect trace concentrations of estradiol in complex environmental samples,it is necessary to establish a convenient,rapid,and simple method of sample pretreatment,which is used in combination with modern detection techniques to analyze estradiol in complex samples.In this paper,estradiol was used as a template molecule,and magnetic Fe₃O₄ nanoparticles were used as the loaded materials.The magnetic molecularly imprinted polymers?MMIPs?was prepared on the surface of modified Fe₃O₄ by surface molecularly imprinted technique.MMIPs is used as a solid phase extraction material to enrich and recycle the estradiol,and the magnetic separation is completed at the time of adsorption,and the pretreatment operation is simplified.The pretreatment method of estradiol in the natural water body was established,and the method was used to analyze the water samples such as deionized water,tap water and reservoir water by using this method and liquid chromatography,and the selective adsorption of estradiol magnetic molecularly imprinted polymer s was researched.Surface molecular imprinting techniques were used to synthesize estradiol magnetic molecularly imprinted polymers?MMIPs?on the surface of modified Fe₃O₄.The optimum reaction conditions were determined by optimizing the ratio of synthetic raw materials and the synthesis conditions.Scanning electron microscopy?SEM?,Fourier transform infrared spectroscopy?FTIR?and X-ray diffractometer analysis?XRD?were used to characterize the surface morphology and structure of the polymer.The synthesis and adsorption mechanism were analyzed.The adsorption and desorption conditions of the estradiol magnetic molecularly imprinted polymer were optimized to determine the optimal enrichment and concentration conditions.The kinetics and thermodynamics of magnetic molecularly imprinted polymers were also studied.The adsorption mechanism was analyzed by using kinetic fitting and isotherm fitting.The results showed that the maximum adsorption capacity of MMIPs for estradiol was 27.35 mg/g,and the adsorption equilibrium time was 40 min.At the same time,three kinds of actual water bodies were tested for spiked recovery.The spiked recover y was 80%⁹3%,and the relative standard deviation?RSD?was 4.5%⁸.2%.Selective adsorption of magnetic molecularly imprinted polymers of estradiol was studied.Endocrine disruptors such as estrone,estriol,bisphenol A,phenol,and sulfamethoxazole were selected as interfering substances in the unit,binary,and multivariate.The competitive adsorption capacity of estradiol was investigated in the system.Also the interference effects of estradiol on the adsorption of estradiol by natural substances such as natural organic matter and anions and cations were also studied.The results showed that the interfering substances in water only reduced the saturated adsorption capacity of estradiol adsorbed by MMIPs,and did not affect the selective adsorption of MMIPs,thus the MMIPs had a good selective adsorption to estradiol.