What do Matrix-Assisted Laser Desorption/Ionization Mass Spectra Reveal about Ionization Mechanisms?
- VISITORS
- ASSOC WESTERN UNIVERSITY
- BATTELLE (PACIFIC NW LAB)
- Vanderbilt University
We describe the results of experiments designed to test several of the most widely discussed mechanistic models for matrix-assisted laser desorption and ionization. By comparing ion mass spectra from the same matrix-analyte systems across various wavelengths from ultraviolet to mid-infrared and pulse durations from nanosecond to femtosecond, we have evaluated the plausibility of such ion-formation mechanisms as multiphoton ionization, excited state ionization, and photothermal ionization. We conclude that some of these models are not plausible for the matrix-analyte systems we studied. However, the fundamental principles of the laser-materials interaction also suggest that inspection of the mass spectra alone can only serve to exclude certain mechanisms, not to establish which of several competing mechanisms is actually occurring. This is particularly true with respect to variations in pulse duration and wavelength.
- Research Organization:
- Pacific Northwest National Lab., Richland, WA (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 15001585
- Report Number(s):
- PNNL-SA-35070; KP1301020; TRN: US200323%%465
- Journal Information:
- Journal of Mass Spectrometry, Vol. 37; Other Information: PBD: 1 Jun 2002
- Country of Publication:
- United States
- Language:
- English
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