Premium
A quantitative model of ultraviolet matrix‐assisted laser desorption/ionization
Author(s) -
Knochenmuss R.
Publication year - 2002
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.349
Subject(s) - chemistry , ionization , desorption , fluence , matrix assisted laser desorption electrospray ionization , plume , yield (engineering) , ion , photoionization , ultraviolet , laser , analytical chemistry (journal) , atomic physics , optics , electron ionization , thermodynamics , chromatography , physics , organic chemistry , adsorption
A quantitative model of primary ionization in ultraviolet matrix‐assisted laser desorption/ionization (UV‐MALDI) is presented. It includes not only photochemical processes such as exciton pooling, but also the effects of the desorption event. The interplay of these two is found to be a crucial aspect of the MALDI process. The desorbing plume is modeled as an adiabatic expansion with entrained clusters. The parameters in the model are defined as much as possible via experiment or by analogy with known effects. The model was applied to the matrix 2,5‐dihydroxybenzoic acid and found to reproduce the fluence dependence of the fluorescence yield and key features of the picosecond two‐pulse ion generation efficiency curves. In addition, the model correctly predicts a fluence rather than irradiance threshold, the magnitude of the threshold, the magnitude of the ion yield, laser wavelength effects, plume temperatures, plume expansion velocities and the spot size effect. Copyright © 2002 John Wiley & Sons, Ltd.