Matrix-assisted ultraviolet laser-desorption ionization time-of-flight mass spectrometry of sulfated mannans from the red seaweed Nothogenia fastigiata
R. Erra-basells et al., Matrix-assisted ultraviolet laser-desorption ionization time-of-flight mass spectrometry of sulfated mannans from the red seaweed Nothogenia fastigiata, CARBOHY RES, 329(1), 2000, pp. 157-167
Matrix-assisted ultraviolet laser-desorption ionization time-of-flight mass
spectrometry (UV-MALDI-TOF-MS) was applied to sulfated xylo-mannan fractio
ns from Nothogenia fastigiata in order to determine their molecular weights
and distribution profiles. The number-average molecular weight calculated
from the spectra was similar to that determined by chemical end-group analy
sis for the lower molecular weight fractions. For the other fractions, the
number-average molecular weight was lower than that chemically determined;
the increased difference may be attributed to higher desorption difficultie
s and, consequently, mass-dependent discrimination. A reconstructed spectru
m, using the peaks obtained from all the fractions, suggested an unimodal d
istribution. The best results were obtained by using 2,5-dihydroxybenzoic a
cid as matrix doped with 1-hydroxyisoquinoline and with harmane and nor-har
mane. (C) 2000 Elsevier Science Ltd. All rights reserved.