Article

Synthesis of molecularly imprinted polymers via ring-opening metathesis polymerization for solid-phase extraction of bisphenol A

College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
Analytical and Bioanalytical Chemistry (Impact Factor: 3.66). 07/2011; 401(4):1423-32. DOI: 10.1007/s00216-011-5178-x
Source: PubMed

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.

0 Bookmarks
 · 
94 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Photoresponsive surface molecular imprinting polymer (SMIP) microspheres were synthesized on silica microspheres by surface polymerization using a water-soluble azobenzene-containing 4-[(4-methacryloyloxy)phenylazo]benzenesulfonic acid as the functional monomer. The SMIP microspheres displayed good photoresponsive properties and specific affinity towards bisphenol A (BPA) with high recognition ability (maximal adsorption capacity: 6.96 μmol g−1) and fast binding kinetics (binding constant: 2.47 × 104 M−1) in aqueous media. Upon alternate irradiation at 365 and 440 nm, the SMIP microspheres could quantitatively bind and release BPA. Analytical application of the SMIP microspheres for the detection of trace BPA concentration in mineral water and tap water has been carried out successfully, and therefore a simple and quick detection method for trace BPA in the environment was established.
    New Journal of Chemistry 03/2014; 38(4). DOI:10.1039/C3NJ01598J · 3.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Thermosensitive molecularly imprinted polymers (T-MIPs) on porous carriers were prepared via the synergy of dual functional monomers of 4-vinylpyridine (VP) and N-isopropylacrylamide (NIPAM), for selective recognition and controlled adsorption and release of bisphenol A (BPA) by the temperature regulation. The porous polymer supporter was synthesized by multistep swelling of polystyrene and then both the NIPAM with temperature responsiveness and the basic monomers of VP were grafted on them in a simple way. The resultant T-MIPs showed high binding capacity, fast kinetics, and the adsorption processes were found to follow Langmuir-Freundlich isotherm and pseudo-second-order kinetic models. The adsorption capacity increased slightly along with the rise of temperature (such as 20°C) under lower critical solution temperature (LCST, 33°C) and decreased fast above LCST (such as 50°C). Subsequently, the T-MIPs were employed as novel adsorbents for selective solid-phase extraction (SPE) of BPA from seawater and yogurt samples. Satisfying recoveries in the range of 94.83-98.47% were obtained with the precision of 3.21% at ambient temperature (20°C). Through 6 adsorption-desorption cycles, the reusable T-MIPs exhibited a good recoverability with the relative standard error within 9.8%. The smart T-MIPs provided great potentials for selective identification, adsorption/release and removal of BPA by simple stimuli responsive regulation.
    Talanta 12/2014; 130:182–191. DOI:10.1016/j.talanta.2014.06.055 · 3.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A new absorbent (polymer) for solid-phase extraction of ractopamine (RAC) was synthesized on the multi-walled carbon nanotubes (MWCTs) using grafting technique and surface imprinting methods. The superficial characteristics of the polymer were studied by scanning electron microscopy (SEM) and UN spectrometry was applied to investigate the static and kinetic adsorption capacity of the new absorbent. After the experimental conditions for the solid-phase extraction of RAC were optimized, a sensing system for the determination of RAC was established by connecting the solid-phase extraction column with a portable amperometric sensing system. The SEM study showed that numbers of imprinted micro-pores were exhibited on the surface of the imprinted polymers, and the absorption experiments indicated that the molecularly imprinted absorbent possessed satisfactory kinetics for the adsorption of ractopamine. The current response of the amperometric sensor demonstrated a linear correlation to the concentration of RAC over the range of 50 to 450 nM (r = 0.998) and the detection limit was 15 nM. Satisfactory sensitivity and stability was also presented under the optimized experimental conditions. The recoveries of RAC samples reached 87.3–94.8% in urine sample.
    Analytical Letters 08/2012; 45(12):1736-1748. DOI:10.1080/00032719.2012.677781 · 0.98 Impact Factor