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Mechanistic Studies on Cationization in MALDI-MS Employing a Split Sample Plate Set-up
Jonas B Metternich1, Martin F Czar1, Mario F Mirabelli1
1Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093, Zurich, Switzerland.
Journal of the American Society for Mass Spectrometry
|August 9, 2019
Summary
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis of polymers shows cation-adduct formation is common. This study provides evidence for gas-phase ionization occurring within the plume during MALDI-MS analysis.
Area of Science:
- Analytical Chemistry
- Polymer Science
- Mass Spectrometry
Background:
- Polymer analysis via MALDI-MS often involves cation-adduct formation due to limited inherent ionizability.
- The precise mechanism, particularly gas-phase cation attachment, requires further elucidation.
Purpose of the Study:
- To investigate the generalizability of gas-phase ionization in MALDI-MS for polymers.
- To provide evidence for in-plume ionization mechanisms.
Main Methods:
- Utilized a split sample plate setup for simultaneous laser irradiation of polymer and salt components.
- Analyzed model polymers poly(methyl methacrylate) and polystyrene using this setup.
Main Results:
- Presented clear evidence supporting in-plume ionization for poly(methyl methacrylate) and polystyrene.
- Quantified the contribution of in-plume processes to overall cationization.
Conclusions:
- The study confirms gas-phase ionization as a significant pathway in polymer MALDI-MS.
- This research offers a foundational estimate for the importance of in-plume ion formation in cationization.
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