噴灑沉積/基質輔助雷射脫附游離-飛行時間質譜法的發展及應用在氮芥子氣之水解產物的快速偵測

Development of Spray Deposition/MALDI-TOFMS and Its Application to the Rapid Screening of Hydrolysis Products Derived from Nitrogen Mustards

林鉅逢(Chu-Feng Lin)

指導教授 ： 林震煌

國立臺灣師範大學/理學院/化學系/碩士(2009年)

摘要

本研究使用基質輔助雷射脫附游離-飛行時間質譜儀結合新穎的樣品配製方法。以α-cyano-4-hydroxycinnamic acid (CHCA) 為基質，分析氮芥子氣之水解產物。使用毛細管噴霧器對樣品及基質進行真空噴灑沉積，使得分析物覆蓋且聚積一層膜在基質輔助雷射脫附游離的承載上。相較於基質輔助雷射脫附游離的傳統樣品配製法，此法減少表面的粗糙，使樣品被均勻摻雜於基質內，聚積在樣品承載上。此方法使偵測極限增加 1~2 個數量級。為了比較傳統方式及真空噴灑沉積方式在樣品承載上的構形，以掃描電子顯微鏡加以觀察，且詳細描述毛細管噴霧的儀器裝置及實驗條件。此方式成功應用於偵測土壤中七種芥子氣的水解產物，此裝置具有很大的潛力可以成為一種常規的偵測工具。
本研究也比較不同游離方式如：電子撞擊游離法、電噴灑游離法及基質輔助雷射脫附游離法對氮芥子氣之水解產物的質譜差異。發現電子撞擊游離法主要以 β-cleavage 斷裂模式為主。電噴灑游離法主要以 [MH+] 斷裂模式為主。而基質輔助雷射脫附游離法，在不同的基質或有無添加三氟醋酸幫助游離下有不同斷裂模式：只有基質CHCA時，離子模式為 [MH+]；7-(Diethylamino)coumarin-3-carboxylic acid (DCCA) 為基質時，斷裂模式為 β-cleavage；若以 CHCA 為基質並添加三氟醋酸幫助游離，則同時擁有各種不同的斷裂模式。

關鍵字

基質輔助雷射脫附游離-飛行時間質譜儀 ； 氮芥子氣之水解產物

並列摘要

A novel method for preparing samples for use in MALDI-TOFMS (matrix-assisted laser desorption ionization time-of-flight mass spectrometry) is described. Seven hydrolysis products derived from nitrogen mustards and CHCA (α-cyano-4-hydroxycinnamic acid) were selected as model compounds and the matrix, respectively. A capillary atomizer was used for evaporative and spray deposition of the sample/matrix solution, leading to the formation of a freestanding film that coated and accumulated on the MALDI substrate (i.e., sample plate). Compared to the traditional method for MALDI, which involves the production of dried droplets, the surface roughness was reduced, resulting in the accumulation of the sample-doped matrix on the sample plate. This resulted in an increase in the limit of detection of 1 - 2 orders of magnitude. In order to compare the structures of the sample-doped matrices obtained by the traditional dried droplet method versus the spray deposition method (developed in this study), the matrices were examined by SEM (scanning electron microscopy). The design of the capillary atomizer and details of the experimental conditions are reported. The application of this method to the above seven degradation products was successful, suggesting that it has great potential for use as a routine monitoring tool.
The research also compared with different dissociation way: electron impact (EI), electrospary ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) mass spectrum to of hydrolysis products derived from nitrogen mustards. In the case of EI, the fragment obtained from β-cleavage is the major process. In the case of ESI, the fragment obtained from [MH+] is the major process. In the case of MALDI, whether there is in the different matrix or does increase the trifluoroacetic acid help dissociation to have the different break pattern. When matrix CHCA, the ion pattern is [MH+]. When matrix DCCA (7-(Diethylamino)coumarin-3-carboxylic acid), the ion pattern is β-cleavage. And increases the trifluoroacetic acid help dissociation by matrix CHCA, then simultaneously has each kind of different break pattern.

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