| Solid phase microextraction(SPME)is widely concerned in the analytical field as a kind of green and solvent free sample pretreatment technology.Fiber coating is the core of the SPME technology.Although some of the coating has been commercialized,the stability and selectivity of these coatings are still flawed,so many scholars are still committed to the study of coating.In this dissertation,three different adsorption materials were prepared.They were coated on the treated stainless steel wires via a simple physical dip method or chemical grafting method to prepare three different solid phase micro-extraction(SPME)fibers.In order to evaluate the extraction capacity of the self-made fibers,the qualitative and quantitative analysis of the model analysis(polychlorinated biphenyls,PCBs)in the Yangtze River water samples was carried out.The main conclusions of this research are as follows:(1)A biochar coated fiber was prepared by a facile physical dip method.The uniform biochar were produced by thermal decomposition of pine needles under limited or absence of oxygen condition.The robust adhesion of biochar to the etched stainless steel support was ensured by the viscosity of epoxy resin.The obtained fiber was utilized for headspace SPME(HS-SPME)of polychlorinated biphenyls(PCBs)from aqueous solution.T Under the optimized conditions,the developed method showed good linearity between 40-320 ng L-1 with R in the range of 0.9817-0.9936.The limits of detection ranged from 12.3 to 24.3 ng L-1.The reproducibility for fiber-to-fiber obtained on two fibers was in the range of 9.5-20.4%.The precisions for intraday were less than 27.8%.The precisions for interday were less than 22.4%.The recovery of fiber to the Yangtze River water sample was between 82.5 and 118%.(2)The fibrous,granular with cavity of polyaniline(PANI)was prepared by interfacial polymerization method.The PANI was adhered to the etched stainless steel wire by dip method using epoxy resin to prepare a SPME fiber.The obtained fiber was utilized for HS-SPME of PCBs from aqueous solution.Experimental results were shown that the developed method has a good linearity between 20 and 200 ng L-1 with R in the range of 0.9701-0.9765.The limits of detection ranged from 10.1 to 19.9 ng L-1.The reproducibility for fiber-to-fiber obtained on two fibers was in the range of 10.2-19.3%.The precisions for intraday were less than 13.0%.The precisions for interday were less than 15.5%.The recoveries were between 78.5-104%.(3)A kind of polymeric ionic liquid(poly-IL)SPME fiber was prepared using the stainless steel wire as a substrate.The oxidation in the H2O2 solution and subsequent silylation in the 3-(trimethoxysilyl)propyl methacrylate-water-methanol mixture of stainless steel wire allowed for methoxyl moieties to be appended to the surface of it.Free-radical initiated polymerization of ionic liquid monomers on the silylated stainless steel wire produced a poly-IL with sheet-like structure.The poly-IL SPME fiber was evaluated with respect to the extraction of PCBs in water samples.Operation parameters,including aging temperature of fiber,extraction time,extraction temperature and ionic strength of water sample,were optimized.Under the optimized conditions,the developed poly-IL SPME fiber showed good linearity between 10 and 200 ng L-1 with R in the range of 0.9918-0.9998 for 12 kinds of PCBs.The limits of detection ranged from 0.9 to 5.8 ng L-1.The reproducibility for fiber-to-fiber obtained on two fibers was in the range of 11.6-20.1%.The precisions for intraday were less than 10.7%.The precisions for interday were less than 12.7%.The recoveries were between 86.6-108%.Experimental results show that three kinds of coating materials have a good adsorption for the selected analytes,and can be used in solid phase microextraction. |
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