Fabrication Of Carbon Baesd Solid-phase Microextraction Coatings And Their Application In The Analysis

In recent years,with the accelerated process of industrialization in China,the existence of aromatic compounds,such as benzene series and phenyl anilines result in the threat of environmental water quality and the safety of drinking water.To ensure the safety of water quality is a major event related to the national economy and the people's livelihood,the detection of aromatic compounds in water is becoming more and more important.However,since the matrix of water becomes more and more complex,the use of analytical instruments for the direct determination is very difficult.Therefore,the development of simple miniaturized sample pretreatment technology is the inevitable trend of the development of contemporary environmental analysis.Based on the fast,effective and sensitive characteristics of solid phase microextraction?SPME?and gas chromatography?GC?,this paper focuses on the method in utilizing two carbon based coatings to analyze the benzene and aniline aromatic pollutants in water coupled with SPME-GC.1.Biochars were prepared by carbonizing pomelo peels using programmed heating carbonization method.The effects of carbonizing conditions on biochars'structure were studied simultaneously.The specific surface area and the pore volume of the biochars which were prepared at different temperatures are analyzed by N₂ adsorption desorption experiments.And Fourier Transform Infrared Spectroscopy and Scanning Electron Microscope were used to observe the organic functional groups and the structure.Compared with commercial activated carbon,biochar has stronger adsorption capacity for naphthalene and phenol,which may be due to their high surface area and?-?conjugation effect.The biochar is immobilized on the surface of stainless steel wire as a SPME coating by sol-gel method and applied to extract benzene from environmental water samples.The results show that the extraction efficiency of the biochar SPME coating is 2.9-18.3 times higher than that commercialization of PDMS?7?m?.In addition,the preparation method combines the sol-gel with good thermal and chemical stability and stainless steel wire with excellent mechanical strength together.So the coating can be used repeatedly for more than 100 times and the extraction efficiency barely decreased.Finally,a SPME-GC analytical method was developed for the analysis of benzene aromatic compounds in river water samples.2.We parpered the AuNPs/OMC coating.OMC was synthesized by template method and AuNPs were in situ grown on the OMC surface to form AuNPs/OMC composites.To study the feasibility of crystal seed method for preparation of composite materials,the N₂adsorption desorption experiment and X-ray ray diffraction?XRD?were used.The AuNPs/OMC combines the merit of?-?electronic configuration and hydrophobic surface of carbon materials,and the strong interaction between AuNPs and amino group.We fabricated OMC coating with a certain thickness by sol-gel method.After that,the seeding method is adopted to synthesize AuNPs/OMC composite coating.And the composite coating was applied to extract anilines from environmental water sample.The results showed that the enrichment factor of Au NPs/OMC coating is 3.7-32 times as much as that of OMC coating and the extraction efficiency of the AuNPs/OMC coating is 2.6-10.8 times higher than the commercial coatings.Finally,under the optimized operation conditions,we developed a SPME-GC method for analyzing anilines in water sample.The linear range,detection limit,precision of the method can meet the requirements of the analysis of anilines aromatic pollutants in water.