| With the rapid development of science and technology,China has made remarkable achievements,but at the same time,it is facing serious environmental pollutions.The removal of environmental pollutants and the pretreatment of complex environmental samples has become an urgent problem to be solved.In this paper,the traditional adsorbents with low adsorption efficiency and poor specificity were eliminated,and the molecularly imprinted polymers with specific recognition ability were synthesized by molecular imprinting technique.The adsorption performance,selectivity and reusability of the imprinted polymer were studied by the batch mode operations.Moreover,the molecularly imprinted solid phase extraction column was prepared,and the polymer was used as adsorbent.The solid phase extraction performance of MISPE column was investigateed.The main points showed as follows:(1)A 4,4’-BPF molecularly imprinted polymer was prepared by bulk polymerization method using 4,4’-BPF as template molecule,α-methacrylic acid as functional monomer and diethanol dimethacrylate as crosslinking agent.The optimal preparation conditions of 4,4’-BPF molecularly imprinted polymer were determined: acetonitrile was the porogen,the optimum molar ratio of the template molecule to the functional monomer was 1:4,and the suitable molar ratio of the functional monomer to the crosslinking agent was 1:5.The structure and morphology of the polymer were characterized by Fourier transform infrared spectroscopy,scanning electron microscopy,specific surface analysis and thermogravimetric analysis.The results showed that under the experimental conditions,4,4’-BPF molecularly imprinted polymer is a kind of cross-linked polymer with spherical,homogeneous morphology,porous and complex pore structure with excellent specific surface area and pore size of 75.67 m2/g and 1.69 nm respectively,and has good thermal stability.(2)The adsorption behavior and identification of 4,4’-BPF on BPF-MIPS were investigated by static adsorption experiments.The results showed that the adsorption amount of BPF-MIPS to 4,4’-BPF was higher than that of NIPS,and the adsorption equilibrium was obtained for about 200 min.The adsorption equilibrium and kinetic data were fitted well with Freundlich model and pseudo-second-order kinetic equation,respectively.Thermodynamics experiments show that the adsorption process is exothermic,spontaneous,and low temperature is favorable for adsorption.Scatchard equation analysis show that BPF-MIPS has a strong adsorption capacity for 4,4’-BPF in the aqueous phase,and there are two different types of binding sites.The maximum apparent adsorption capacity of the high affinity binding site reached 37.1 mg/g,and the equilibrium dissociation constant was 2.03×10-5 mol/ L.Selective experiments show that BPF-MIPS have a good selectivity for 4,4’-BPF,and the selectivity factors for bisphenol A and phenol were 2.07 and 11.7,respectively.The amount of 4,4’-BPF adsorbed after repeated 8 times of the polymer was still 94.9% when used for the first time,and showed good regeneration performance.(3)Moleculary imprinted solid phase extraction column(MISPE)was filled with BPF-MIPS.Methanol-water(7/3,v/v)was used as washing solution,methanol-acetic acid(9/1,v/v)as eluting solution;The breakthrough volume of MISPE column was 60 mL,the penetrating capacity was 5.98 mg/g,the total mass transfer coefficient was 0.0339 s-1,the mass transfer zone length was 20.44 mm,and the MISPE column exhibits specific adsorption to 4,4’-BPF,and the 4,4’-BPF in water environment can be separated and enriched. |
