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研究生: 丁素梅
Ting, Su May
論文名稱: 以熱脫附/雙冷凍聚集法及氣相層析質譜儀測定大氣中二十三種微量揮發
The Determination of Twenty-three Trace Volatile Compounds in
指導教授: 吳家誠
Wu, Jia-Cheng
學位類別: 碩士
Master
系所名稱: 化學系
Department of Chemistry
畢業學年度: 84
語文別: 中文
論文頁數: 3
中文關鍵詞: 熱脫附雙冷凍聚集法氣相層析質譜儀揮發性化合物
英文關鍵詞: Thermal Desorption, Two-stage-cryogenic Focusing, GC-MS, Volatile Compounds
論文種類: 學術論文
相關次數: 點閱:321下載:0
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  • 揮發性有機化合物(Volatic Organic Compounds,
    VOCs.)是造成健康影響的重要空氣毒性污染物,長期暴露在VOCs.的環境
    下會導致人體細胞中DNA 改變所產生的致癌性,以及對呼吸道、眼睛等黏
    膜組織所引起的刺激性反應。此外,許多VOCs.對中樞神經也可能產生麻醉
    作用。

    為評估VOCs 在光化學作用及生理毒性作用的影響,近年來有關VOCs 之分
    析方法研究已著重在發展一套可偵測較多種類的化合物和較低偵測濃度的
    採樣分析技術。本研究針對文獻中已有之VOCs 測定法加以研究測試並進
    一步改良,以建立一套適用於國內的氣態微量有機化合物的採樣、貯存及
    分析技術,此技術利用Tenax TA 為吸附劑進行採樣,經熱脫附後以 GC-FID
    及 GC-MS 來進行定性定量上的分析,在分析過程中並使用含同位素及不
    含同位素之內標準品,以增加定性及定量之準確性。

    空氣樣本的採集是利用低流量幫浦帶動空氣通過填充 Tenax TA 吸附
    劑(500 mg)的採樣管將VOCs 吸附捕集。分析程序首先是以180℃的高溫將
    採樣管中的VOCs 脫附出來,用液態氮將分析樣品冷凝濃縮於冷凝管,再
    以氦氣為載送氣體將脫附出來的VOCs 載送到氣相層析儀中,經毛細管層
    析管柱分離後以質譜儀進行定性、定量的分析。分析測定結果發現熱脫附
    裝置的脫附效率可達90 %以上,23 種主要分析目標污染物的方法回收率
    測試範圍在78.3 %~109.0 %,方法偵測極限範圍在0.69 ng~6.32 ng
    ,停滯時間的再現性相對標準偏差範圍介於0.25 %~1.26 %之間,此方
    法廣泛地進行現場實地採樣,以證實其應用於真實樣品的可行性。

    The volatile organic compounds (VOCs) are important
    toxic pollutants in the ambient air which can affect human
    health. If one is exposed in the environment with high level of
    VOCs will cause physiological changes including DNA damages that
    may lead to cancer. Exposure to VOCs will also bring stimulation
    of mucous membrane of the breathway and eyes. Besides, VOCs can
    anesthetize the centeral nerve system.

    In order to estimate the effects of VOCs on our environment and
    toxic damagesto human physiology, analytical techniques for VOCs
    have been recently emphasized on developing procedures detect
    much more compounds and at lower concentrations. The instruments
    used in this work. Including thermal desorption system, GC-FID
    and GC-MS. In the process of analysis, internal standards with
    or without istopes are used to enhance the accuracy of
    determination. Low-volume-flow pumps are used
    to drive the air sample through the column packed with Tenax TA
    as adsorbent to collect VOCs. At first, VOCs in the sampling
    column are analytes desorbed at temperature of 180℃. Then are
    condensed in the cryo-trap by liquid nitrogen. Helium acts as
    carrier gas to drive the desorbed VOCs to GC. Finally, the
    analytes separated by a capillary column goes on for quilitative
    and quantitative analysis in MS. In this study, the overall
    recoveries range from 78.3% to 109.8%. The rae of detection
    limits is 0.69 ngqsymbol 126 "Symbol" s 12 ~ 6.32 ng. The
    relative standard deviations of relention times the range of
    0.26% symbol 126 "Symbol" s 12 ~ 1.26%. The feasibility of
    this method is tested by real sample analyses from different
    sources.
    The volatile organic compounds (VOCs) are important

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