Preparation Of Porous Organic Polymers And Their Applications In The Determination Of Some Pollutants Residues

Porous organic polymers?POPs?constructed by organic structural units have attracted increasing attention from researchers due to their high specific surface area,light composition elements,highly ordered porosity,easy functionalization,adjustable pore structure and good physical and chemical stability.POPs have been used in gas storage,adsorption,separation and catalysis,energy,and sensors with good performance.In this study,three kinds of POPs were prepared and used as adsorbents for magnetic solid phase extraction?MSPE?and solid phase extraction?SPE?of some pesticide residues in environmental and food samples,followed by high performance liquid chromatography?HPLC?analysis.Thus,new and sensitive analytical methods with POPs as adsorbent were developed for the determination of pesticide residues in real samples.The main research contents are as follows:1.A magnetic mesoporous poly?melamine-formaldehyde?composite?Fe3O4-mPMF? was prepared via grafting poly?melamine-formaldehyde?onto the surface of amino-functionalized magnetite?Fe3O4?nanoparticles.The material was characterized by scanning electron micrography,transmission electron microscopy,X-ray diffraction,FT-IR,nitrogen adsorption-desorption isotherms,and thermo gravimetric analysis.It has a large surface area,the typical mesoporous structure,and a high thermal stability.It was employed as a magnetic sorbent for the solid phase extraction of endocrine disrupting chemicals?EDCs?including bisphenol A,4-tert-butylphenol,4-tert-octylphenol and nonylphenol,followed by quantification with HPLC.Under the optimized conditions,the response to EDCs is linear in the range of 0.5-100.0 ng/mL,and the limits of detection are0.02-0.1 ng/mL.The high adsorption capability of the Fe₃O₄-mPMF is mainly attributed to multiple interactions including?-stacking,hydrogen bonding,and hydrophobic interactions.The method was applied to analyze EDCs in river water and bottled juice samples.The results demonstrated that the Fe3O4-mPMF is an efficient adsorbent for the extraction of organic compounds with large conjugated?-system,plenty of hydrogen-bonding sites,and strong hydrophobicity.2.A simple and eco-friendly synthetic approach was used to fabricate a novel o-hydroxyazobenzene porous organic polymer?HAzo-POP?by diazo-coupling of2,6-diaminoanthraquinone with m-trihydroxybenzene in aqueous solution.The HAzo-POP possesses good stability and high adsorption capability towards aromatic organic pollutants due to its porous nature,highly conjugated structure and strong hydrogen bonding ability.The HAzo-POP was successfully used for the solid-phase extraction of phenylurea herbicides from six real samples prior to high performance liquid chromatography with ultraviolet detection.The analytical method showed good linearity in the range of0.5-160.0 ng/g for celery,lettuce and tomato samples,and 0.4-160.0 ng/mL for milk,soybean milk and juice samples,with low limits of detection in the range from 0.05 to 0.30ng/g?or/mL?.The HAzo-POP has a promising application potential for the adsorption of more aromatic organic compounds.3.A covalent organic framework?named as DAAQ-TFP?was prepared via a fast,environmentally-friendly,and easy-to-perform grinding method with2,6-diaminoanthraquinone?DAAQ?and 1,3,5-triformylphloroglucinol?TFP?as building blocks.The DAAQ-TFP possesses large surface area,high porosity,good thermochemical stability,abundant O atoms and N-H groups,which render it great potential as sorbent for some compounds.It was employed as adsorbent to extract benzoylurea insecticides?BUs?from environmental water,juice,fruit and vegetables samples,followed by their determination with high-performance liquid chromatography?HPLC?.The DAAQ-TFP showed a high adsorption capacity for BUs,and the developed method provided a low limit of detection and high method recoveries.To explore its application potential and also to clarify the possible adsorption mechanisms of the DAAQ-TFP toward BUs,it was tested to extract different types of compounds,proving that the DAAQ-TFP can serve as a superior adsorbent,and adsorption mechanism is mainly based on the?-?stacking and H bonding.