%0 Journal Article %T A novel solid-phase microextraction using coated fiber based sol–gel technique using poly(ethylene glycol) grafted multi-walled carbon nanotubes for determination of benzene, toluene, ethylbenzene and o-xylene in water samples with gas chromatography-flam ionization detector %A Sarafraz Yazdi, Ali %A Amiri, Amir Hassan %A Ronaghi, Gholam Hossein %A Eshtiagh Hosseini, Hossein %J Journal of Chromatography A %@ 0021-9673 %D 2011