自動氣相層析質譜儀於揮發性有機化合物之分析技術與應用

Development and Applications of Automated Gas Chromatography-Mass Spectrometry for the Analysis of Volatile Organic Compounds

蘇源昌(Yuan-chang Su)

指導教授 ： 王家麟

國立中央大學/理學院/化學系/博士(2011年)

摘要

本研究的重點在於開發與改進自動化氣相層析質譜儀系統，用於監測大氣中的揮發性有機污染物，並將已開發完成之技術應用於野地實測，以表現氣相層析質譜儀於自動即時監測系統之應用性與價值。本研究主要分為兩大部分，前半部主要探討實驗系統硬體的開發與改進，後半部則將開發完成的系統應用於工業區中進行實測。
在系統硬體開發與改進方面主要可分為三個主題：(1)在此將分流機制引入層析系統中進行研究，研究結果發現分流機制可使額外管柱效應中的Vtub2與Vinj2降低，用以提高層析圖譜之解析度，進而提升處理數據的效率以及數據品質；(2)將二維層析技術應用於氣相層析質譜儀，在研究過程中我們開發了兩種中心切割技術方法，分別為「滯留法」以及「逆吹法」，並找出了最佳化條件，使用質譜儀作為偵測器並應用中心切割技術達到量測全範圍(C3~C12)揮發性有機污染物之目的；(3)以中孔徑吸附劑MCM-48作為吸附材料進行研究，並建構新型的冷凍前濃縮系統以降低吸附溫度，檢視中孔徑材料的吸脫附特性以及應用性，於實驗結果發現中孔洞材料具有低脫附溫度的特性，相較於商業化碳吸附劑具有較低的記憶效應以及較好的淨化效率。
在實測工作中，本研究以桃園縣觀音工業區、高雄縣大發工業區、以及雲林縣的六輕工業區作為探討的廠址，將其所得的數據分別與人工採樣分析、各類商業化之快速質譜儀進行比對，檢視自動化氣相層析質譜儀系統的穩定度以及效能，研究結果發現人工採樣以及自動化氣相層析質譜儀系統兩者皆具有良好的定性凾能，可利用監測結果建立工業區可能的污染物質排放清單；而快速質譜儀與自動化氣相層析質譜儀所量測的結果具有良好的一致性，驗證該系統的可信度以及量測效能；最終即時量測數據與風場模式的模擬結果結合，將所發展的量測技術與現有的科學模式相互映證。由以上結果，可確立自動化氣相層析質譜儀用於污染源評鑑之應用價值，並根據各種量測系統以及模式模擬結果，建立監測工業區空氣污染物之標準流程。

關鍵字

氣相層析質譜儀 ； 揮發性有機污染物

並列摘要

The objective of this research is to develop an automated gas chromatographic mass spectrometry (GC-MS) system for monitoring volatile organic compounds (VOCs). The content divides into two parts. The first part describes the technical improvement of the automated GC-MS system. The second part is to apply the developed system to measure VOCs in the field.
There are three subjects comprised in the first part of technical improvements. (1) The split mechanism of injection was introduced into chromatographic system. The mechanism reduces two main factors of extra column effect, Vtub2 and Vinj2, to enhance resolution of chromatogram resulted in improving processing data efficiency and data quality. (2)Two-dimensional chromatographic (heart-cutting) technique was applied to GC-MS system. We have developed two operational modes naming “hold-up method” and “backflush & trap method”. The parameters and resolutions of the two modes were tuned and compared with each other. The optimized condition of the system was capable to measure the full range of VOCs from C3 to C12. (3) In this research, we have investigated the sorption/desorption properties and applicability of MCM-48 as a sorbent for on-line gas chromatographic analysis of ambient VOCs. Two trapping temperatures of 30°C versus -20°C were tested by trapping a full range of VOCs from C2 to C12. The required desorption temperatures of MCM-48 (100-180°C) were much lower than carbon sorbents(＞200°C). As a result, the large pores of MCM-48 with low memory effect can desorb VOCs more efficient.
In field campaigns, the air qualities of three industrial parks (Kuangin of Taoyuan County, Dafa of Gaoxiong County, and Sixth Naphtha Cracking of Yunlin County) were investigated. The data of in-situ monitoring site acquired by GC-MS were compared with analysis of off-line sampling and commercial mass spectrometry in order to examine their reliability and efficacy. The analysis of off-line sampling as well as GC-MS has the capability of establishing the list of VOC in industrial park and data measured by commercial mass spectrometry and GC-MS are in agreement on trend of VOC. In the end, the data provided by in-situ GC-MS system and Wind Model can verify and compromise each other. The results have confirmed the utility and applicability of GC-MS in a standard operation procedure of monitoring VOC.

並列關鍵字

GC-MS ； volatile organic compounds

參考文獻

2. Fenger, J., Urban air quality. Atmospheric Environment 1999, 33, (29), 4877-4900.

3. Wang, Q. g.; Han, Z.; Wang, T.; Zhang, R., Impacts of biogenic emissions of VOC and NOx on tropospheric ozone during summertime in eastern China. Science of The Total Environment 2008, 395, (1), 41-49.

4. Wei, X. L.; Li, Y. S.; Lam, K. S.; Wang, A. Y.; Wang, T. J., Impact of biogenic VOC emissions on a tropical cyclone-related ozone episode in the Pearl River Delta region, China. Atmospheric Environment 2007, 41, (36), 7851-7864.

7. Carter , W., Development of ozone reactivity scales for volatile organic compounds. J.Air waste manage. Assoc. 1994, 44, 881-899.

8. Seinfeld, J. H. P., ATMOSPHERIC CHEMISTRY AND PHYSICS. John Wiley & Sons,: 1998.