The Study Of Extraction Technique For Analysis Of Organic Impurities In Fuel Gas By GC-MS

Determination and monitoring the concentrations of organic impurities in fuel gas are very improtant.However,due to the complicated compositions and low concentration levels,the selected impurities in fuel gas are difficult to gather. Up to now,few references are available for directly and accurately monitoring the concentration levels of them.Therefore,a new sample enrichment method or deviece with high efficient is essential before further analysis.In this work,SPE and SPME techniques are proposed to analyze the organic inpurities in fuel gas.Solid phase extraction (SPE) is a simple,convenient and cost-effective technique,which shows valuable ability for sample extraction and concentration.The study focused on choosing the right adsorbent to extract and preconcentrate the organic impurities in gas sample directly,followed by content determination.In this work,a graphitized carbon black-based dynamic SPE setup for sampling and preconcentration of aromatics in fuel gas was constructed.The target aromatics(benzene,toluene,xylene isomers,styrene,indene and naphthalene)were rapidly collected from fuel gas in flow-through mode and analyzed by gas chromatography-mass spectrometry (GC-MS). Several parameters,such as sampling duration,gas flow rate,elution condition,breakthrough efficiency and reproducibility,were optimized to obtain the best SPE preconcentration condition.Solid-phase microextraction (SPME) technique is a simple,fast and solvent-free sample preparation technique.The preparation of SPME coating palys an important part in the development of SPME technique.hi this paper,a novel route to prepare graphene based SPME coating on stainless steel wire was developed. Graphene was prepared and successfully immobilized on modified stainless steel wire by chemical-bonding. Then,a practical SPME device with a hollow polytetrafluoroethylene tube as interface was designed and the stainless steel fiber was fixed to the handle by the strong adhesion of epoxy resin.The new fiber showed a highly homogeneous and wrinkled structure,with about20μm in thickness.The extraction performance was investigated by the determination of aromatics in fuel gas followed by thermal desorption and GC-MS analysis.Experiment results showed that the graphene coated fiber showed high repeatability, together with low cost and simple to prepare. The home-made SPME fiber has the potential ability for analysis of organic impurities in fuel gas.