ArticleJournal of the American Society for Mass Spectrometry2012
Degree of ionization in MALDI of peptides: thermal explanation for the gas-phase ion formation.
Article in Journal of the American Society for Mass Spectrometry, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers.
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Who cites it
13 citing papers in PubMed, 44 citations in OpenAlex.
- Subtle concentration changes in zinc hold the key to fibrillation of α-synuclein: an updated insight on the micronutrient's role in prevention of neurodegenerative disorders.Frontiers in molecular biosciences · 2025Review
- The Influence of MS Imaging Parameters on UV-MALDI Desorption and Ion Yield.Journal of the American Society for Mass Spectrometry · 2019Article
- Observing Proton Transfer Reactions Inside the MALDI Plume: Experimental and Theoretical Insight into MALDI Gas-Phase Reactions.Journal of the American Society for Mass Spectrometry · 2017Article
- Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry: Mechanistic Studies and Methods for Improving the Structural Identification of Carbohydrates.Mass spectrometry (Tokyo, Japan) · 2017Article
- Critical factors determining the quantification capability of matrix-assisted laser desorption/ionization- time-of-flight mass spectrometry.Philosophical transactions. Series A, Mathematical, physical, and engineering sciences · 2016Review
- Ghost peaks observed after atmospheric pressure matrix-assisted laser desorption/ionization experiments may disclose new ionization mechanism of matrix-assisted hypersonic velocity impact ionization.Rapid communications in mass spectrometry : RCM · 2015Article
- Ion-to-Neutral Ratios and Thermal Proton Transfer in Matrix-Assisted Laser Desorption/Ionization.Journal of the American Society for Mass Spectrometry · 2015Article
- Energetics and kinetics of thermal ionization models of MALDI.Journal of the American Society for Mass Spectrometry · 2014Article
- Spectral reproducibility and quantification of peptides in MALDI of samples prepared by micro-spotting.Journal of the American Society for Mass Spectrometry · 2014Article
- Thermal proton transfer reactions in ultraviolet matrix-assisted laser desorption/ionization.Journal of the American Society for Mass Spectrometry · 2014Article
- Why do the abundances of ions generated by MALDI look thermally determined?Journal of the American Society for Mass Spectrometry · 2013Article
- Efficient methods to generate reproducible mass spectra in matrix-assisted laser desorption ionization of peptides.Journal of the American Society for Mass Spectrometry · 2013Article
- MALDI and Related Methods: A Solved Problem or Still a Mystery?Mass spectrometry (Tokyo, Japan) · 2013Article
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Authors and funding
4 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Degree of ionization (DI) in matrix-assisted laser desorption ionization (MALDI) was measured for five peptides using α-cyano-4-hydroxycinnanmic acid (CHCA) as the matrix. DIs were low 10(-4) for peptides and 10(-7) for CHCA. Total number of ions (i.e., peptide plus matrix) was the same regardless of peptides and their concentration, setting the number of gas-phase ions generated from a pure matrix as the upper limit to that of peptide ions. Positively charged cluster ions were too weak to support the ion formation via such ions. The total number of gas-phase ions generated by MALDI, and that from pure CHCA, was unaffected by the laser pulse energy, invalidating laser-induced ionization of matrix molecules as the mechanism for the primary ion formation. Instead, the excitation of matrix by laser is simply a way of supplying thermal energy to the sample. Accepting strong Coulomb attraction felt by cations in a solid sample, we propose three hypotheses for gas-phase peptide ion formation. In Hypothesis 1, they originate from the dielectrically screened peptide ions in the sample. In Hypothesis 2, the preformed peptide ions are released as part of neutral ion pairs, which generate gas-phase peptide ions via reaction with matrix-derived cations. In Hypothesis 3, neutral peptides released by ablation get protonated via reaction with matrix-derived cations.
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