Molecularly imprinted layer-coated silica nanoparticles for selective solid-phase extraction of bisphenol A from chemical cleansing and cosmetics samples.

Highly selective molecularly imprinted layer-coated silica nanoparticles for bisphenol A (BPA) were synthesized by molecular imprinting technique with a sol-gel process on the supporter of silica nanoparticles. The BPA-imprinted silica nanoparticles were characterized by fourier transform infrared spectrometer, transmission electron microscope, dynamic adsorption and static adsorption tests. The equilibrium association constant, K(a), and the apparent maximum number of binding sites, Q(max), were estimated to be 1.25 x 10(5) mL micromol(-1) and 16.4 micromol g(-1), respectively. The BPA-imprinted silica nanoparticles solid-phase extraction (SPE) column had higher selectivity for BPA than the commercial C18-SPE column. The results of the study indicated that the prepared BPA-imprinted silica nanoparticles exhibited high adsorption capacity and selectivity, and offered a fast kinetics for the rebinding of BPA. The BPA-imprinted silica nanoparticles were successfully used in SPE to selectively enrich and determine BPA from shampoo, bath lotion and cosmetic cream samples. Copyright 2009 Elsevier B.V. All rights reserved.