Novel sponge-like molecularly imprinted mesoporous silica material for selective isolation of bisphenol A and its...

Bisphenol A (BPA) imprinted sponge mesoporous silica was synthesized using a combination of semi-covalent molecular imprinting and simple self-assembly process. The molecularly imprinted sponge mesoporous silica (MISMS) material obtained was characterized by FT-IR, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption measurements. The results show that the MISMS possessed a large specific surface area (850.55 m(2) g(-1)) and a highly interconnected 3-D porous network. As a result, the MISMS demonstrated a superior specific adsorption capacity of 169.22 μmol g(-1) and fast adsorption kinetics (reaching equilibrium within 3 min) for BPA. Good class selectivity for BPA and its analogues (bisphenol F, bisphenol B, bisphenol E and bisphenol AF) was also demonstrated by the sorption experiment. The MISMS as solid-phase extraction (SPE) material was then evaluated for isolation and clean-up of these bisphenols (BPs) from sediment samples. An accurate and sensitive analytical method based on the MISMS-SPE coupled with HPLC-DAD has been successfully established for simultaneous determination of five BPs in river sediments with detection limits of 0.43-0.71 ng g(-1) dry weight (dw). The recoveries of BPs for lyophilizated sediment samples at two spiking levels (50 and 500 ng g(-1) dw for each BP) were in the range of 75.5-105.5% with RSD values below 7.5%.