利用基質輔助雷射脫附游離技術氣化Phe-Gly分子以探討其NEXAFS光譜與斷鍵機制

NEXAFS Spectra and Dissociation of Core Excited Phe-Gly from Matrix-Assisted Laser Desorption/Ionization

江昱儒(Yu-Ju Chiang) ； 林宜學(Yi-Shiue Lin) ； 劉振霖(Chen-Lin Liu)

《真空科技》 30卷4期 (2017/12) Pp. 48-57

摘要

基質輔助雷射脫附游離法(Matrix-assisted Laser Desorption/Ionization, MALDI)是一種能有效分析各類型非揮發性生物分子的分析方法，並具有高靈敏度與準確性之優點。於MALDI技術中，待測樣品由分析物與基質以適當比例混合而成，基質吸收脈衝雷射光子能量而氣化，並同時將分析物帶入氣相環境。於本研究中，我們選用2,5-dihydroxybenzoic acid (2,5-DHB)作為基質，利用MALDI技術將分析物Phenylalanyl-glycine (Phe-Gly)分子氣化，再藉由不同能量之軟X光(Soft X-ray)將其游離、分解，結合飛行時間質譜儀測量質譜與X光吸收近邊緣結構(Near-Edge X-ray Absorption Fine Structure, NEXAFS)光譜，探討Phe-Gly分子的解離 途徑與原子化學環境之關聯。

關鍵字

基質輔助雷射脫附游離法 ； 飛行時間質譜儀 ； X光吸收近邊緣結構圖譜 ； 軟X光 ； 同步輻射

並列摘要

Matrix-assisted laser desorption/ionization (MALDI) is a powerful method for analyzing various types of non-volatile biomolecules due to its high accuracy and sensitivity. In the MALDI mechanism, sample is composed of a mixture of analyte and matrix with suitable ratios. When pulsed laser beam irradiates the sample surface, the matrix molecules absorb photons that convert to heat energy. A part of matrix molecules can be vaporized and simultaneously carry analyte molecules into gaseous phase. In this work, we mixed phenylalanylglycine (Phe-Gly) with a conventional matrix of 2,5-dihydroxybenzoic acid (2,5-DHB). The desorbed neutral molecules were ionized and fragmented following absorbing a soft X-ray photon. Near-edge X-ray absorption fine structure (NEXAFS) spectra and ionized neutral molecules were analyzed by using MALDI-TOF-MS system.

並列關鍵字

MALDI ； TOF-MS ； NEXAFS ； Soft X-ray ； Synchrotron radiation