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Matrix‐assisted laser desorption with ultra‐short laser pulses
Author(s) -
Demirev P.,
Westman A.,
Reimann C. T.,
Håkansson P.,
Barofsky D.,
Sundqvist B. U. R.,
Cheng Y. D.,
Seibt W.,
Siegbahn K.
Publication year - 1992
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.1290060307
Subject(s) - laser , full width at half maximum , nitrogen laser , chemistry , excimer laser , laser power scaling , ultraviolet , ultrafast laser spectroscopy , ion , dye laser , matrix assisted laser desorption electrospray ionization , optics , power density , analytical chemistry (journal) , power (physics) , ion source , physics , organic chemistry , chromatography , quantum mechanics , thermal ionization mass spectrometry
An excimer pumped dye laser generating ultra‐short (560 fs full width at half maximum, FWHM) pulses in the ultraviolet (UV, 248 nm) and visible (496 nm) spectral ranges is used to desorb protein ions from different matrices. The effects of laser‐light energy and power density on secondary‐ion yields from insulin are reported. These data are compared to data obtained by employing a nitrogen laser (337 nm, 3 ns FWHM). The existence of a threshold energy density for the matrix‐asisted laser desorbtion (MALD) of insulin ions by the ultra‐short pulses is established. This threshold energy is of the same order of magnitude for the two laser systems employed and does not depend on the laser pulse length (the energy deposition time). Thus we demonstrate that the amount of laser energy deposited into the sample, rather than the laser power, is the important parameter in the MALD process.