標題: Analysis of Initial Reactions of MALDI Based on Chemical Properties of Matrixes and Excitation Condition
作者: Lai, Yin-Hung
Wang, Chia-Chen
Chen, Chiu Wen
Liu, Bo-Hong
Lin, Sheng Hsien
Lee, Yuan Tseh
Wang, Yi-Sheng
應用化學系
Department of Applied Chemistry
公開日期: 1-一月-1970
摘要: "This investigation concerns the initial chemical reactions that affect the ionization of matrixes in matrix-assisted laser desorption/ionization (MALDI). The study focuses on the relaxations of photon energy that occur on a comparable time scale to that of ionization, in which the available laser energy is shared and the ionization condition is changed. The relaxations include fluorescence, fragmentation, and nonradiative relaxation from the excited state to the ground state. With high absorption cross section and long excited-state lifetime, photoionization of matrix plays an important role if sufficient laser energy is used. Under other conditions, thermal ionization of the molecule in the ground state is predicted to be one of the important reactions. Evidence of change in the branching ratio of initial reactions with the matrix and the excitation wavelength was obtained with alpha-cyano-4-hydroxycinnamic acid, sinapinic acid, 2,5-dihydroxybenzoic acid, and 2,4,6-trihydroxyacetophenone. These matrixes are studied by obtaining their mixed crystal absorption spectra, fluorescence properties, laser-induced infrared emission, and product ions. The exact ionization pathway depends on the chemical properties of matrixes and the excitation conditions. This concept may explain the diversity of experimental results observed in MALDI experiments, which provides an insight into the ensemble of chemical reactions that govern the generation of ions."
URI: http://hdl.handle.net/11536/16730
ISSN: 1520-6106
期刊: JOURNAL OF PHYSICAL CHEMISTRY B
Volume: 116
Issue: 32
結束頁: 9635
顯示於類別:期刊論文


文件中的檔案:

  1. 000307494500009.pdf