Influence of the Wavelength in High-Irradiance Ultraviolet Laser Desorption Mass Spectrometry of Organic Molecules by Michael Karas and others

Analytical Chemistry 57, 2935–2939 (1985). Original first-page byline Michael Karas, Doris Bachmann and Franz Hillenkamp. Page 2937, Figure5 and “Matrix-Assisted Laser Desorption”: alanine/tryptophan mixture at 266nm, alanine ion formation at about one tenth of the irradiance required for alanine alone. The paper discusses competing mechanistic interpretations rather than establishing one universal ionization pathway.