Ultraviolet Laser Induced Hydrogen Transfer Reaction: Study of the First Step of MALDI In-Source Decay Mass Spectrometry

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• 作者：Daiki Asakawa ; David Calligaris ; Nicolas Smargiasso ; Edwin De Pauw
• 刊名：The Journal of Physical Chemistry B
• 出版年：2013
• 出版时间：February 28, 2013
• 年：2013
• 卷：117
• 期：8
• 页码：2321-2327
• 全文大小：401K
• 年卷期：v.117,no.8(February 28, 2013)
• ISSN：1520-5207

文摘

The early mechanisms of matrix-assisted laser desorption/ionization in-source decay (MALDI-ISD) are described herein. MALDI-ISD is initiated by the hydrogen transfer from excited matrix molecules to the carbonyl oxygen of the peptide backbone, which is followed by a radical-induced cleavage, producing the c鈥?z鈥?fragment pair. As expected, the use of 2,5-DHB or 1,5-DAN was efficient to induce MALDI-ISD, and the strongest intensity of MALDI-ISD fragments was observed when laser shots were performed on matrix crystals. In contrast, the hydrogen radical transfer reaction was suppressed by using ionic liquid and amorphous structure of 2,5-DHB and 1,5-DAN mixture as a matrix. Our results suggest that the hydrogen transfer occurs on the matrix crystal during the dissipation of the laser energy and before desorption, following ISD fragments formed in the MALDI plume.