Preparation And Application Of Functional Materials Modified Organic Polymer Monolithic Columns

Polymer monolithic microextraction(PMME)is a branch of solid-phase microextraction(SPME),which has the advantages of simple preparation,wide range of modification,good biocompatibility and less consumption of samples and solvents.These advantages make it widely used in the analysis of many types of real samples.However,due to the complexity and diversity of sample matrice and low efficiency of traditional polymer monolithic columns for the preconcentration of small molecules,the research on the modification and functionalization of polymer monolithic column has become an hot topic.Porous materials consist of inorganic porous materials and organic porous materials.Inorganic porous materials mainly include activated carbon and zeolite,while organic porous materials can be devided into a variety of types.Porous materials usually have low relative density,light weight,high strength,good permeability,and high specific surface area.In view of these advantages,porous materials are very suitable for the modification of polymer monolithic columns to improve the swelling effect and enhance the extraction ability.Supramolecular materials are a kind of complicated materials with host and guest interactions,which are formed by intermolecular forces between more than two molecules.The active groups on supramolecular material surface benefit to the modification of polymer monolithic column.Moreover,many active sites on the surface can be used to enhance the enrichment efficiency of polymer monolith toward a variety of small molecules.In this work,porous materials and supramolecular materials were used to improve the permeability and stability of polymer monolithic column,and provide active sites to enhance the interactions between the monolithic materials and various small molecules.By coupling with high performance liquid chromatography(HPLC),the enrichment and detection of organic small molecules in cosmetics and biological samples were carried out.The main contents are as follows:1.A novel zeolite-modified poly(methacrylic acid-ethylenedimethacrylate)monolithic column was prepared with the in situ polymerization method and employed in PMME for enrichment and detection of synthetic colorants combined with HPLC.The polymer monolithic material was characterized by scanning electronmicroscopy,Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,and thermo-gravimetric analysis.Various parameters affecting the extraction efficiency were investigated and optimized.Under the optimum experimental conditions,we obtained acceptable linearities,low limits of detection,and satisfactory intra-day/inter-day relative standard deviations.The method was applied to the determination of synthetic colorants in lipsticks with recoveries ranged from 70.7% to 109.7%.Compared with conventional methacrylic acid-based monoliths,the developed monolith exhibited high enrichment capacity because of the introduction of zeolites into the preparation process.2.Covalent organic framework(COF)was introduced into a poly(glycidyl methacrylate-ethylene dimethacrylate)monolith inside a capillary via photo-induced thiol-epoxy click polymerization.The COF modified monolithic material was characterized using scanning electron microscopy,Fourier-transformed infrared spectroscopy,X-ray photoelectron spectroscopy,and thermal gravimetric analysis.The novel polymer monolithic material was employed in PMME for preconcentration of benzophenones.Under the optimum conditions,acceptable linearities,low limits of detection,and good intra-day/inter-day relative standard deviations were obtained.The developed PMME-HPLC method was applied to the determination of benzophenones in human urine and serum samples.3.A novel polymer monolithic material was copolymerized by the in-situ synthesis by polymer monomers and melamine-based covalent organic polymer/ionic liquid hybrid composite.The polymer monolithic material was employed in PMME for preconcentration of synthetic phenolic antioxidants.The obtained polymer monolithic material was confirmed by scanning electron microscopy,Fourier-transformed infrared spectroscopy,X-ray photoelectron spectroscopy,and thermal gravimetric analysis.The polymer monolithic column exhibited good stability and repeatability.The intra-day and inter-day relative standard deviations were both less than 10%.The developed PMME-HPLC method was applied for the preconcentration and determination of synthetic phenolic antioxidants in cosmetic samples and assessed through recovery studies.The results demonstrated that the synthesized polymer monolithic material had potential as a candidate in the preconcentration field for PMME.4.A calix[4]arene derivative was introduced into the poly(butyl methacrylate-ethylene dimethacrylate)monolith inside a capillary to prepare a polymer monolithic material employed in PMME.Various techniques including scanning electron microscopy,Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,and thermo-gravimetric analysis were employed to characterize the synthesized polymer monolithic material.A new method was developed for the preconcentration and analysis of bisphenols using PMME coupled with HPLC.Under the optimized conditions,the monolithic column afforded acceptable linearities,low limits of detection,and good intra-day/inter-day relative standard deviations.The PMME-HPLC method was applied to the determination of bisphenols in human serum samples with recoveries ranged from 77.6% to 109.7%.5.A novel monolithic capillary column modified with layered double hydroxide(LDH)was developed and employed in PMME for the preconcentration of fluorescent whitening agents combined with HPLC.LDH was embedded in the poly(dimethyl diallyl ammonium chloride-ethylene dimethacrylate)monolith via in situ polymerization.The characteristic properties of LDH and modified monolith were characterized using X-ray diffraction,scanning electron microscope,Fourier-transformed infrared spectra,and thermal gravimetric analysis.After optimizing various experimental parameters,the developed method was validated and applied to the determination of fluorescent whitening agents in mask essence samples.