z-logo
Premium
Evaluation of mass discrimination effects in the quantitative analysis of polydisperse polymers by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry using uniform oligostyrenes
Author(s) -
Shimada Kayori,
Lusenkova Marina A.,
Sato Keisuke,
Saito Takeshi,
Matsuyama Shigetomo,
Nakahara Hisae,
Kinugasa Shinichi
Publication year - 2001
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/rcm.224
Subject(s) - chemistry , dispersity , mass spectrometry , analytical chemistry (journal) , mass spectrum , molecular mass , polystyrene , molar mass distribution , time of flight mass spectrometry , desorption , ionization , matrix assisted laser desorption/ionization , polymer , matrix (chemical analysis) , chromatography , adsorption , ion , polymer chemistry , organic chemistry , enzyme
Mass discrimination effects in matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) were quantitatively investigated using equiweight and equimolar mixtures of uniform polystyrene (PS) oligomers. Uniform PS oligomers were separated by preparative super‐critical fluid chromatography (SFC) from commercial standard PS samples. The separated PS oligomers, with degrees of polymerization n  = 2–25, have absolutely no molecular weight distributions. Equiweight and equimolar mixtures of uniform PS oligomers were accurately prepared by weighing by microbalance, and their spectra were recorded using a MALDI‐TOF mass spectrometer. In the lower molecular weight region (less than about 10 3 ) the oligomers with lower molecular weights give lower mass spectral intensities, with no correlation with laser power. In contrast, higher laser powers yield a decrease of mass spectral intensities in the higher molecular weight region. These results clearly show that mass discrimination effects occur at lower and higher molecular weights depending on the laser power, and provide quantitative information about the discrimination. Using the data on equiweight and equimolar mixtures of PS oligomers, it was possible to calibrate the MALDI‐TOF mass spectral data for an analysis of molecular weight distribution of a standard monodisperse PS sample with number‐averaged molecular weight of 10 3 , and to compare it with the molecular weight distribution measured by analytical SFC. The result from the calibrated MALDI‐TOF mass spectrum, however, does not agree perfectly with that from the SFC results, because undetectable peaks in MALDI‐TOF mass spectra at lower and higher molecular weights could not be included in the calibration of peak intensities. Copyright © 2001 John Wiley & Sons, Ltd.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here