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Effect of sample preparation methods on the analysis of dispersed polysaccharides by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Author(s) -
Chan P. K.,
Dominic Chan T.W.
Publication year - 2000
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/1097-0231(20001015)14:19<1841::aid-rcm104>3.0.co;2-q
Subject(s) - chemistry , chromatography , mass spectrometry , analytical chemistry (journal) , sample preparation , desorption , matrix (chemical analysis) , sample preparation in mass spectrometry , matrix assisted laser desorption/ionization , dispersity , mass fraction , gel permeation chromatography , polymer , electrospray ionization , adsorption , polymer chemistry , organic chemistry
Effect of sample preparation methods on the matrix‐assisted laser desorption/ionization (MALDI) analysis of dispersed polysaccharides is reported. By using the conventional drop‐drying method, the measured number‐averaged molecular weights were found to differ significantly from the values obtained from gel‐permeation chromatography (GPC). These discrepancies were found to increase as the average masses of the polysaccharides increased. To understand the impact of the sample preparation method on the MALDI measurement, a dispersed dextran sample was separated into ten narrow‐distribution fractions. Mixtures of different mass fractions were prepared and analyzed by using different mixing and preparation methods. By using the ratio of the signal intensity for the low‐mass fraction to that of the high‐mass fraction as an indicator, the impact of sample preparation conditions on the enhancement of low‐mass components (or suppression of high‐mass components) was determined. From the results obtained, it is postulated that the difference in solubilities between the low‐mass and high‐mass components for dispersed polymers might be large enough to induce an enhancement of low‐mass components (or suppression of high‐mass components) at the surface of the crystals during sample crystallization in the drop‐drying method. Copyright © 2000 John Wiley & Sons, Ltd.