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  • 學位論文

雷射脫附-質子轉移反應質譜儀之開發暨其對生物分子之偵測應用與相關研究

Development and Related Studies of Laser Desorption-Proton Transfer Reaction-Mass Spectrometry for Biomolecule Detection

指導教授 : 李遠哲
共同指導教授 : 陳仲瑄(Chung-Hsuan Chen)

摘要


本論文的工作內容是開發與研究「雷射脫附-質子轉移反應質譜儀」-結合雷射脫附技術和質子轉移反應質譜儀而得的新式質譜議。雷射脫附-質子轉移反應質譜儀可以偵測位於表面上的非揮發性物質,特別是生物分子,包括胜肽、蛋白質及醣類。分析樣品被雷射輻射脫附至氣相中,與試劑離子碰撞,再經由質子轉移反應而游離。為產生試劑離子,亦自行研製空心陰極放電裝置。我們發現對生物分子最佳的試劑離子為水合質子 (H+(H2O)n) 或氨合質子 (H+(NH3)m)。以雷射脫附-質子轉移反應質譜儀所觀測到的離子訊號,主要來自質子化分子型離子。因為使用水(氨)合質子當作試劑離子,其所造成的釋放能減小與蒸發冷卻效應,使得裂解效應降至最低。質量分析是以自製的線型飛行質譜議完成。 在此工作中,我們測試了一系列不同類型的試劑離子與雷射脫附方法,尋求最佳化條件以利雷射脫附-質子轉移反應的進行。這些被測試過的試劑離子包括H3+, H3O+, NH4+, H+(H2O)n, 和 H+(NH3)m。而用來做雷射脫附的方法則可以區分成石墨輔助、基質輔助、離子性液態基質輔助和冰狀基質輔助雷射脫附。 雷射脫附-質子轉移反應質譜儀具備下列特性:軟性游離生物分子;檢驗雷射脫附氣團內的中性分子並且揭示其中的機制;擴展了傳統「質子轉移反應質譜儀」的應用範疇,從揮發性有機化合物到非揮發性化合物;提供新式工具來研究生物分子在氣相中的質子轉移反應相關化學,這方面的文獻十分缺乏,尤其是醣類;提昇生物質譜技術中的游離效率;以效率最高的化學游離方式,也就是質子轉移反應,來進行生物分子的「雷射脫附後-游離」;支持「質子轉移反應在基質輔助-雷射脫附游離中扮演重要角色」的觀念。 這篇論文的部份工作已在「第四屆國際質子轉移反應質譜儀暨應用會議,奧地利,2009」中的新式儀器議程中以口頭報告的方式公開發表,亦在「第236屆美國化學學會國家會議與展覽,費城,2008」和「第238屆美國化學學會國家會議與展覽,華盛頓特區,2009」中公開報告。

並列摘要


Laser Desorption Proton Transfer Reaction Mass Spectrometry (LD-PTR-MS), a novel technique which combines Laser Desorption (LD) method with Proton Transfer Reaction-Mass Spectrometry (PTR-MS), had been developed and studied in this work. LD-PTR-MS can be utilized to detect nonvolatile compounds on surface, especially biomolecules including peptides, proteins and carbohydrates. The analytes are desorbed into the gas-phase by laser irradiance, collide with the reagent ions, and then are ionized via proton transfer reactions. A home-made hollow cathode discharge (HCD) device was employed to generate the reagent ions. The optimum reagent ions for biomolecules were found to be water or ammonia solvated protons, that is, H+(H2O)n or H+(NH3)m. Protnated-molecular ions were the most dominant features in LD-PTR-MS mass spectra while fragmentation was minimized by the reduction of reaction exoergicity and evaporative cooling effect when using solvated protons as the reagent ions. Mass analysis was done by a home-built linear time-of-flight mass spectrometry (TOF-MS). In this work, a various types of reagent ions and laser desorption schemes have been investigated to seek the optimum processing conditions for LD-PTR. The reagent ions tested include H3+, H3O+, NH4+, H+(H2O)n, and H+(NH3)m. And the laser desorption schemes employed can be classified into graphite assisted (GA), matrix assisted (MA), ionic liquid matrix assisted (ILMA) and icy matrix assisted (IMA) laser desorption. LD-PTR-MS has the following features: to softly ionize biomolecules; to examine the neutrals within LD plume and unravel the mechanisms involved; and to extend the application of PTR-MS from volatile organic compounds (VOCs) to nonvolatile compounds; to provide a new tool to study proton transfer reaction of biomolecules in the gas-phase, especially carbohydrates which are in lack of corresponding literature; to enhance the ionization efficiency of biological mass spectrometry; to post-ionize biomolecules by the most sensitive technology, PTR-MS; to support the idea of that “gas-phase proton transfer reaction played an important role in MALDI mechanism.” Part of the results was presented in oral in the Instruments & Technology session at the 4th International Conference on Proton Transfer Reaction-Mass Spectrometry and its Applications, in Obergurgl, Austria, February 16-21, 2009. It was also presented at the 236th American Chemical Society National Meeting& Exposition, in Philadelphia, PA, August 17-21, 2008; and at the 238th American Chemical Society National Meeting& Exposition, in Washington, D.C., August 16-20, 2009.

參考文獻


77. Jorgensen, T. J. D.; Bojesen, G.; Rahbek-Nielsen, H. European Mass Spectrometry 1998, 4, (1), 39-45.
40. Vanbreemen, R. B.; Snow, M.; Cotter, R. J. International Journal of Mass Spectrometry and Ion Processes 1983, 49, (1), 35-50.
70. Harrison, A. G.; Yalcin, T. International Journal of Mass Spectrometry 1997, 165, 339-347.
96. Armstrong, D. W.; Zhang, L. K.; He, L. F.; Gross, M. L. Analytical Chemistry 2001, 73, (15), 3679-3686.
10. Fenn, J. B.; Mann, M.; Meng, C. K.; Wong, S. F.; Whitehouse, C. M. Science 1989, 246, (4926), 64-71.

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