Monodisperse restricted access material with molecularly imprinted surface for selective solid-phase extraction of 17β-estradiol from milk.

In this study, novel monodisperse restricted access media-molecularly imprinted polymers were successfully prepared by surface initiated reversible addition-fragmentation chain transfer polymerization using monodisperse crosslinked poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres as the carrier and acryloyl chloride-modified beta-cyclodextrin as the hydrophilic functional monomer. The surface morphology, protein exclusion, and adsorption properties of the molecularly imprinted polymers were investigated. The results show that the material has excellent monodispersity and hydrophilicity, and simultaneously exhibit high adsorption capacity, fast binding kinetics, high selectivity, and significant thermal stability. The molecularly imprinted polymers as dispersive solid-phase extraction adsorbent combined with reversed-phase high-performance liquid chromatography was used to selectively enrich, separate, and analyze trace 17 beta-estradiol in milk samples. The recovery of 17 beta-estradiol is 88-95% with relative standard deviation of <4%, and the limits of detection and quantification of this method are 2.08 and 9.29 mu g/L, respectively. The novel restricted access media-molecularly imprinted polymer adsorbents provide an effective method for the selective extraction and detection of 17 beta-estradiol directly from complex samples.