Synthesis of molecularly imprinted polymers via ring-opening metathesis polymerization for solid-phase extraction of bisphenol A.
ABSTRACT The use of molecularly imprinted polymers (MIPs) prepared by ring-opening metathesis polymerization (ROMP) for bisphenol A (BPA) was reported in this article. The resulting MIPs have high imprinting and adsorption capacities, and can be used for separation and determination of BPA in environmental water samples. The successful application of ROMP in the molecular imprinting field is described here. For the first time, two cross-linkers (dicyclopentadiene and 2,5-norbornadiene) and two Grubbs catalysts (first and second generation) were investigated to compare their effects on the binding performance of MIPs. The ROMP technique is able to create the imprinted polymers within 1 h under mild conditions. Furthermore, it can provide MIPs with obvious imprinting effects towards the template, very fast template rebinding kinetics, high binding capacity and appreciable selectivity over structurally related compounds. The adsorption process for MIPs in this study can be completed within 45 min, which is much faster than that of bulk MIPs synthesized by traditional free-radical polymerization. The resulting imprinting polymer was evaluated for its use as a sorbent support in an off-line solid-phase extraction approach to recover BPA from diluted aqueous samples. The optimized extraction protocol resulted in a reliable MISPE method suitable for selective extraction and preconcentration of BPA from tap water, human urine and liquid milk samples. This article demonstrates the practical feasibility of the MIPs prepared via ROMP as solid-phase extraction materials.
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ABSTRACT: A new dummy template molecule, N,N’-bis(3-vinylbenzylidene)-4,4′-diaminodiphenylmethane (VB-DADPM) was designed to synthesize dummy template imprinted polymer (DIP) for Bisphenol A (BPA). Since the Schiff-base part of VB-DADPM is easily cleaved by a weak acid treatment, the DADPM moiety can be removed after the co-polymerization with crosslinkers. After the post-imprinting oxidation□was carried out to transform the residual aldehyde to carboxylic acid, binding sites toward BPA were generated only inside the binding cavity, which had an estimated binding constant of 1.3 × 10 M, and could recognize the difference between similar molecules BPA and BPB, the latter of which has an ethyl group instead of a methyl group at the central part of BPA.Analytical Letters - ANAL LETT. 01/2012;