Study On The Preparation And Extraction Performance Of Novel Solid Phase Microextraction Multiple Fibers

Solid phase microextraction(SPME)is one of the most important methods in sample pretreatment,which integrate extraction,purification,and enrichment.Multiple monolithic fibers SPME(MMF-SPME),designed and developed by our group,inherits the advantages of SPME and monolithic materials,such as simple operation,abundant raw materials,high extraction capacity and easy chemical modification.Therefore,MMF-SPME can enrich the target analytes rapidly and efficiently.In this study,three new types of monolithic materials were prepared and used as the extraction media of MMF-SPME,then coupled with high performance liquid chromatography/diode array detector(HPLC-DAD),established a series of sensitive analysis methods to detect trace organic pollutants in environmental,food and biological samples.The main research contents are as follows:(1)Poly(1-trimethyl-(4-vinylbenzyl)aminium chloride-co-divinylbenzene/ethylene glycol dimethacrylate)monolithic fiber was prepared and used to extract the phenolic endocrine disrupting chemicals in environmental water and biological samples.The effect of the ratios of monomer to cross-linker and monomer mixture to porogenic solvent were studied thoroughly.The synthesized material was characterized by fourier transform infrared spectrometer(FTIR),scanning electronic microscopy(SEM),element analysis and other characterization techniques.Under the optimum extraction conditions,the method of MMF-SPME-HPLC-DAD was successfully applied to determine trace phenolic endocrine disrupting chemicals in environmental water and human urine samples.The linear range of the proposed method was 0.1-200.0 ?g/L.The limit of determination(LOD)and limit of quantification(LOQ)were in the ranges of 0.011?0.065 ?g/L and 0.036?0.21 ?g/L,respectively.At the same time,the recovery of the sample and the repeatability of the experiment were satisfactory.(2)Acrylamidophenyl-boronic acid and 1-vinylimidazole were used as mixed functional monomers to synthesize a new monolithic adsorbent.This material was employed as the extraction phase of MMF-SPME.Results well show that the prepared adsorbent could extract sulfonylurea herbicides(SUHs)in environmental water and soil samples effectively through multiply interactions such as boronate affinity,?-? and dipole-dipole interactions.The concentration of monomer,cross-linker and porogenic solvent in polymerization solution were investigated,and finally obtained the adsorbent with expected mechanical strength and extraction performance.The surface and internal structure of material were characterized by some techniques.After optimization of extraction parameters,a method of MMF-SPME coupled with HPLC-DAD was conducted to detect trace SUHs in environmental water and soil samples.All linear dynamic ranges possess good linearity(R2>0.99).The LODs for target objects in environmental water and soil samples were 0.018?0.17 ?g/L and 0.14?1.23 ?g/kg,respectively,the LOQs were 0.061?0.44 ?g/L and 0.45?4.06 ?g/kg,respectively.The relative standard deviations(RSD)of intra-and inter-day assay were 1.3?9.9%.In addition,this method was applied to monitor trace SUHs in environmental water and soil samples with a satisfactory recovery and reproducibility results.(3)In order to enlarge specific surface area of the adsorbent,a novel monolithic material incorporated with graphene(VEGN/MMF)was prepared.Selecting phenoxyalkanoic acid herbicides(PAs)as the target objects,optimizing the ratio of graphene in the polymerization solution,and then established a method of VEGN/MMF-SPME-HPLC-DAD to determine trace PAs in environmental water and rice samples.The LOD and LOQ values were in the range of 0.093?0.12 ?g/L and 0.31?0.41 ?g/L,respectively,for water sample.The corresponding values in rice samples were 0.36?0.66 ?g/kg and 1.18?2.27 ?g/kg,respectively.The recoveries of real samples were varied from 70.7%to 118%,which can meet the determination requirements of trace phenoxy carboxylic herbicides in the environmental and food samples.