Selective Solid-phase Extraction of Bisphenol A Using a Novel Stir Bar Based on Molecularly Imprinted Monolithic Material

In this paper, a novel monolithic stir bar based on molecularly imprinted polymer (MIP) was firstly developed by filling modified neodymium magnet (Nd2Fe14B) powders into a glass tube (60 x 4 mm), followed by the imprinted grafting with bisphenol A (BPA) as the template molecule by thermal polymerization. It has been successfully used for the stir bar sorptive extraction (SBSE) and its extraction performance illustrated that the MIP-encapsulated stir bar had stronger affinity to the template molecule, compared with the stir bar based on the non-imprinted molecularly polymer (NIP). Under the optimal extraction conditions, a simple method based on the coupling of MIP-SBSE with high performance liquid chromatography (HPLC) was used for the selective determination of the model mixtures of BPA, 4-phenylphenol (PP) and phenol (P) in bottled water. The recoveries of BPA, PP and P were in the range of 88.5-96.1%, 78.2-89.7%, 81.3-89.5% at three spiked levels, respectively, demonstrating that higher extraction and the specific absorption occurred between the template molecule and the prepared MIP stir bar.