標題: | Solid-Phase Thermodynamic Interpretation of Ion Desorption in Matrix-Assisted Laser Desorption/Ionization |
作者: | Lai, Yin-Hung Wang, Chia-Chen Lin, Sheng-Hsian Lee, Yuan Tseh Wang, Yi-Sheng 交大名義發表 National Chiao Tung University |
公開日期: | 4-十一月-2010 |
摘要: | This work demonstrates a quantitative interpretation of ion desorption in matrix-assisted laser desorption/ionization (MALDI). The theoretical modeling incorporates transition state theory for the desorption of surface ions, assuming chemical and thermal equilibrium in the solid state prior to desorption. It is distinct from conventional models that assume chemical equilibrium in the gas phase. This solid-state thermodynamic interpretation was used to examine the desorption of pure 2,4,6-trihydroxyacetophenone (THAP) and of angiotensin I mixed with THAP. It successfully described the changes in ion yield with the effective temperature under various laser fluence and initial temperature conditions. The analysis also revealed the key role played by ion concentration in the modeling to provide the best fit of the model to observations. On the other hand, divergence of the ion beam with laser fluence was examined using an imaging detection method, and the signal saturation normally seen at high fluence was appropriately reduced by ion focusing. Simplified but deceptive theoretical interpretations were obtained when the analysis was conducted without adequate calibration of the instrument bias. |
URI: | http://dx.doi.org/10.1021/jp104250g http://hdl.handle.net/11536/31945 |
ISSN: | 1520-6106 |
DOI: | 10.1021/jp104250g |
期刊: | JOURNAL OF PHYSICAL CHEMISTRY B |
Volume: | 114 |
Issue: | 43 |
起始頁: | 13847 |
結束頁: | 13852 |
顯示於類別: | 期刊論文 |