| Summary: | 碩士 === 輔仁大學 === 化學系 === 98 === The objective of this study is to design, fabricate and characterize a micro preconcentrator that directly synthesize carbon based adsorbent film inside an pre-sealed, anodic bonded micro channel. Parameters for the synthesis of carbon film adsorbent such as starting hydrocarbon materials, temperature program and reducing atmosphere were investigated. It is found that carbon film synthesized using cellulose as starting material and slowly heated at a rate of 10℃/min to 600℃ and maintained for two hours under high purity nitrogen shows best sorption/ desorption properties. The porous structure was inspected by FE-SEM. Good durability, fabrication reproducibility and sufficiently narrow for chromatographic injection of preconcentrated mixtures were validated in this study. The μ-preconcentrator containing 1.2 mg of carbon membrane can sample 200ppb of toluene, benzene up to 1.6L and acetone up to 0.89L before breakthrough. Preconcentration factor of 13637 for toluene was empirically determined. The desorption peak width under 2 seconds were obtained under optimized desorption temperature of 320℃and desorption flow rate of 3 mL/min. Finally, we applied Wheeler model to assess the thermodynamic capacity of our synthesized adsorbent and found the mean value is 0.752±0.02 mg/g.
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