Ordered mesoporous carbon in solid-phase microextraction for analysis of volatile organic compounds in water samples

An ordered mesoporous carbon (OMC) film supported on graphite fiber was prepared by a dip-coating method combined with a solvent evaporation induced self-assembly (EISA) strategy. The supported OMC film served as a solid-phase microextraction coating. N-2 isothermal adsorption measurements, scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR spectroscopy, contact angle measurement and Raman spectra were used for characterization. The effects of the preparation conditions on the SPME performance of the OMC fibers were first studied by analyzing three kinds of compounds with different physical-chemical properties: BTEX, PAHs and CPs. The characterization results showed that all the OMC materials prepared under different conditions have a well-ordered two-dimensional hexagonal mesostructure. The effects of the preparation conditions on the SPME performance of the OMC coating were evaluated. The results show that the OMC700 fiber has high sensitivity for nonpolar BTEX and PAHs and the OMC350 fiber is favourable for extracting polar CPs. The extraction efficiency of BTEX obtained with the OMC700 fiber is 2.0-5.5 times higher than that of commercial PDMS (100 mu m) fiber and the extraction efficiency of PAHs obtained with the OMC700 fiber is 2.6-3.8 times higher than that of commercial PDMS/DVB (65 mu m) fiber.