UV Optical Absorption of Matrices Used for Matrix-assisted Laser Desorption/Ionization

✍ Scribed by D. A. Allwood; R. W. Dreyfus; I. K. Perera; P. E. Dyer

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 473 KB
• Volume: 10
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(199610)10:13<1575::aid-rcm658>3.0.co;2-c

✦ Synopsis

Previous modelling of the matrix-assisted laser desorptiodionization (MALDI) process has had to rely on matrix solution optical absorptivities whereas the value for the solid phase is more appropriate. Absorption bands are usually broader for solids than for solutions due to the higher concentration in the former, hence solution values generally overestimate the solid absorptivity. In order to rectify this shortcoming, the present work reports values of the optical absorption coefficient (a) of sublimed MALDI matrix films with measured thicknesses of 50 to 6OOnm. The matrix compounds studied were ferulic acid, sinapinic acid, a-cyano4hydroxycinnamic acid, 2,5-dihydroxybenzoic acid, (2,5-DHB), nicotinic acid and c o d 124). I0 general the films showed integrated cross-sections (oscillator strengths) similar to those determined by measurements on the respective solutions. Scanning electron microscopy of 2,5-DHB and coumarin 120 films showed them to consist of a uniform layer of sub-micron (-300 nm) crystallites.