| Pharmaceuticals and personal care products(PPCPs)are emerging environmental pollutants.Most of these compounds have chiral centers.Molecularly imprinted polymer(MIP)is a kind of polymer that has specific recognition ability and matches the template molecule in its spatial structure and binding sites.Stir bar sorptive extraction(SBSE)is widely used in sample pretreatment.Combining molecular imprinting technology and SBSE,chiral molecularly imprinted polymeric(CMIP)coatings were prepared for the naproxen enantiomers analysis in PPCPs.In this paper,the distribution of chiral PPCPs in the environment and its harm to environmental organisms were introduced.The detection methods of naproxen enantiomers were reviewed.The development and application of stir bar sorptive extraction in recent 20 years were mainly introduced.In this study,a chiral molecularly imprinted polymer was prepared using a chiral template molecule and a chiral functional monomer.The chiral molecularly imprinted polymer was used for stir bar sorptive extraction and applied for the analysis of chiral enantiomers in actual samples.The main contents are as follows:A chiral molecularly imprinted stir bar sorptive extraction coating was prepared.The template molecule and functional monomer are both chiral compounds.S-naproxen is a chiral template molecule.R-cysteine,S-cysteine and N-acetyl-R-cysteine are used as chiral functional monomers,respectively.The preparation process was optimized,including the molar ratio and polymerization solvents.A variety of CMIPs coatings and corresponding CNIPs and 4-VP-MIP coatings were prepared.The CMIP coating was synthesized under the mixing ratio of 1:4:30 for template,functional monomer and crosslinker.The chiral functional monomer R-cysteine and the solvent DMSO-method(1:1)were used to prepared heterochiral MIP coating,which the best CMIP coating was selected for subsequent research by the results of extracting S-naproxen.The extraction conditions of CMIP coating were optimized.The result showed that the best conditions were 180 min of extraction time,10 min of desorption time,methanol of desorption solvent,23 % Na Cl and 4.0 of p H value.Under the optimal extraction conditions,the extraction capacity of the CMIP,CNIP and 4-VP-MIP coatings were evaluated.The extraction capacity of the CMIP coating was greater than the other two kinds of coatings.S-naproxen,R-naproxen,S-ibuprofen and phenol were simultaneously evaluated for the selective study by the CMIP coating.The results showed that the CMIP coating had better extraction capacity of S-naproxen than the other compounds,and the extraction rate was higher than that of the other compounds.The extraction recovery of CMIP coating for S-naproxen extraction was 44 % and the IF was 1.32.The CMIP coating was used to enrich the enantiomers of naproxen in chiral drugs and environmental water samples.The recovery of S-naproxen was 84.93%-116.18%.The recovery of R-naproxen was 83.98%-118.88%.And the relative standard deviation was 3.49%-13.08%.Various characterization methods were further used to characterize the coatings structure,such as SEM,AFM,FT-IR,and XRD.The results showed that the functional groups of CMIP and CNIP coatings were similar.CMIP coating had more obvious cavity,rough surface morphology and higher three-dimensional framework,which was conducive to the adsorption of S-Naproxen.The main pores of CMIP coating were 2-5 nm,and ordered mesopores were formed in self-assembly.UV-vis spectroscopy was used to study the intermolecular forces between chiral template molecules and chiral functional monomers.Furthermore,computer theoretical calculations were also employed to calculate the interaction between different chiral functional monomers and template molecules.The result showed that the heterochiral mixture of S-naproxen and R-cysteine had the strongest intermolecular force. |
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