Sajad Pirsa - Department of Chemistry, Factually of Science, Tarbiat Modares University, P.O.Box ۱۴۱۱۵-۱۷۵, Tehran, Iran
Naader Alizadeh - Department of Chemistry, Factually of Science, Tarbiat Modares University, P.O.Box ۱۴۱۱۵-۱۷۵, Tehran, Iran

A new analytical method using gas chromatography combined with conducting polypyrrole gas sensor has been developed for the detection of DMSO in water [1]. The morphology of the polypyrrole (PPy) conducting film on the surface of the fibers was examined by scanning electron microscope (SEM). The sensing behavior of PPy-coated fiber sensor (PPy-CFS) was investigated in the presence of different VOCs. GC/ PPy-CFS could detect and quantify various VOCs, enabling to provide pattern analysis results [2]. The PPy-CFS as GC detector exhibited linear responses to DMSO, amines, hexane, heptanes, DMF and so. The resistive responses of the PPy-CFS to VOCs were in the order of DMSO> (ROH)> Ketone > Acetonitril > Chloroform > Benzene, Toluen, m-Xylen > RH. The effects of flow rate and Temperature on the response of the detector were also investigated and discussed. The mass effects examined for DMSO indicated that the conductive polymer detector was quite sensitive to the DMSO with good reproducibility and good detection limits. Limits of detection (LODs) for DMSO calculated as ten times the baseline noise under optimum conditions. The LOD for the DMSO was 50 ng. The sensor shows a short response time (<1 s) in the whole mass flow rate range