Sk. Zhao et al., STUDIES OF SOME CHARACTERS OF MATRIX INFLUENCING DESORPTION IONIZATION PROCESSES IN MATRIX-ASSISTED LASER-DESORPTION IONIZATION MASS-SPECTROMETRY, Analytical sciences, 13, 1997, pp. 45-48
Some results are introduced in studying characters of matrices influen
cing the desorption ionization processes in MALDI-MS, which have not b
een reported. By the use of low angle laser scattering photometer the
association state of four matrices with lysozyme are measured. The res
ults demonstrated that 3-amino-4-hydroxybenzoic acid (3A4HA) is the be
st one which call be calculated 224 molecules to associate with one mo
lecule of lysozyme. The other three matrices, nicotinic acid (NA), 2,5
dihydroxybenzoic acid (DHB) and caffeic acid (CA) are in the order of
several tens of matrix molecules associated with one protein molecule
. It is interesting to point out that 3-amino-4-hydroxybenzoic acid is
the only one that cannot perform MALDI-MS spectrum and the reason is
discussed. The results of the investigation in negative MALDI mass spe
ctra of different matrices demonstrated that the desorption ionization
processes are different with that of positive ions, and their mechani
sms were proposed.