Ere. Vanderhage et al., STRUCTURAL-ANALYSIS OF POLYOXYALKYLENEAMINES BY MATRIX-ASSISTED LASERDESORPTION IONIZATION ON AN EXTERNAL ION-SOURCE FT-ICR-MS AND NMR/, Macromolecules, 30(15), 1997, pp. 4302-4309
Matrix-assisted laser desorption:ionization (MALDI) and Fourier-transf
orm ion cyclotron mass spectrometry (ET-ICR-R IS) are combined for the
characterization of polyoxyalkleneamines. H-1 and C-13 NMR data are u
sed to confirm and quantify structural assignments. Characterization o
f the molecular weight distribution, chemical composition distribution
, and end group distribution of amine-terminated (co-)polymers of ethy
lene oxide and propylene oxide is rather complex because the convoluti
on of these three entities yields an ensemble of structurally related
molecules which is hard to characterize by conventional analytical tec
hniques. In this study MALDI FT-ICR-MS is used to resolve intact, Nacationized, oligomer ions in the mass range From m/2 500 to 3500. This
revealed the presence of various compositional distributions in the p
olyoxyalkyleneamines. The individual compound masses in the molecular
weight distributions were measured with a mass accuracy of <20 millima
ss units, allowing end group and repeat unit determination with an acc
uracy of better than 50 millimass units. NMR is used to measure the av
erage end group distribution to provide insight in conformational diff
erences. Zn this respect, FT-ICR-MS data and NMR data are complementar
y. The combined results yield detailed information about chemical comp
osition distributions of polyoxyalkyleneamines that hitherto it was no
t possible to obtain with either technique separately.