Da. Allwood et al., OPTICAL-ABSORPTION OF MATRIX COMPOUNDS FOR LASER-INDUCED DESORPTION AND IONIZATION (MALDI), Applied surface science, 110, 1997, pp. 154-157
Citations number
5
Categorie Soggetti
Physics, Condensed Matter","Chemistry Physical","Materials Science, Coatings & Films
Values of the optical absorption coefficient have been determined for
chemically similar (C7H6O4,5 - ring structure) matrix-assisted laser d
esorption/ionization (MALDI) matrices, prepared as solid-phase sublima
ted thin films (100 nm-1 mu m thickness). Sublimated films were found
to have multi-peaked absorption spectra with an absorption coefficient
at 337 nm of between 1.66 x 10(4) cm(-1) ('poor' matrix) and 7.95 x 1
0(4) cm(-1) ('excellent' matrix [H. Ehring, M. Karas and F. Hillenkamp
, Org. Mass Spectrom. 27 (1992) 472]). These measurements have allowed
an investigation of the effect that the solid-phase absorption coeffi
cient has on the MALDI process. A direct correlation exists between a
molecule's optical absorptivity and its suitability as a matrix at tha
t wavelength, i.e. efficiency in producing ions. This is exemplified b
y mass spectrometric analysis which shows a dramatic improvement in th
e performance of the most poorly rated 337 nm matrix when desorbed usi
ng the XeCl (308 nm) laser, the molecule displaying a higher absorptio
n coefficient at this wavelength.