Fabrication Of Novel Solid Phase Microextraction Fiber Based On Ordered Mesoporous Carbon And Study On Its Extraction Properties

Solid phase microextraction(SPME)is a kind of analytical technique for sample pretreatment.It integrates extraction,enrichment and injection into one single step.The technique is based on the absorption or adsorption process between the sample and the coating of fiber.Therefore the solid phase microextraction fiber plays an important role in SPME technique.So far,a variety of fibers are commercially available.However,these commercials fibers exhibit several shortcomings,such as short lifetime,instability in organic solvent and low operating temperature.Thus it is necessary to develop a novel SPME fiber to overcome these disadvantages.Carbon materials are always considered as promising candidates for SPME coating materials.Among them,ordered mesoporous carbon(OMC)is a novel porous carbon material with excellent adsorption capability and stability in harsh environment.Herein,an OMC coating supported on the stainless wire introduced as SPME fiber was fabricated to overcome above shortcomings.This paper mainly focuses on the following three parts:First,the OMC fiber was prepared by physical coating.The results show that the OMC powder possessed a surface area of 701.413 m~2/g and a pore volume of 0.353 cm~3/g with a narrow peak centering at 3.4 nm.The thickness of OMC coating is about 100?m.The coating is tightly affixed to the surface of stainless wire.Secondly,the stability of OMC fiber and its extraction selectivity were also studied.The fiber could be used at temperatures up to 350~oC and has excellent solvent resistance.What's more,the fiber enabled to extract for more than 150 cycles.Extraction selectivity of OMC fiber was evaluated based on the peak area for a series of environmental prior compounds.The result illustrated that OMC fiber had the higher affinity to aromatic low-polar compounds.And OMC fiber was seemed to be easier to“catch”compounds with substituents,such as methyl or chlorine atom.Furthermore,OMC fiber was expected to follow the same discipline under the mix system.Thirdly,the OMC fiber was applied into analysis of benzene series in aqueous media.The SPME extraction conditions were optimized:via headspace extraction method;extraction temperature:30 ~oC;extraction time:40 min;stirring rate:1200 r/min;ion strength:0%;desorption temperature:250 ~oC;desorption time:3 min.The linear rage of developed method based on above optimized conditions was in the range of 1-1000?g/L;the limit of detection was in the range of 0.086-0.088?g/L;the RSD values fluctuated from 2.0%to 5.5%with one fiber and 2.5%to10.6%with three different fiber;the recoveries fluctuated from of 81.0%to 112.8%in spiked water samples.Compared with commercial fibers,OMC fiber has higher affinity to benzene series.In summary,the SPME fiber in this paper have good extraction capability,excellent physical and chemical stability,wide detection rang and good repeatability.The results satisfied requirements of analysis and demonstrated the applicability of OMC fiber into the analysis of benzene series and other environmental prior pollutants in aqueous media.