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The Influence of Laser Energy of MALDI on the Molecular Mass Distribution of Synthetic Polymers

Published

Author(s)

S Wetzel, Charles M. Guttman, Kathleen M. Flynn

Abstract

The desorption/ionization process of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is not completely understood. Characterization of synthetic polymers by MALDI-TOF-MS is very sensitive to the instrument and sample preparation parameters that are needed to obtain a mass spectrum. The molecular mass distribution (MMD) that is obtained in polymer characterization may be biased by preferential desorption/ionization of low mass polymer molecules, preferential ion attachment to larger polymers, or degradation and fragmentation due to the desorption process. In this study we focus on the effect of the laser energy on the molecular mass distribution of three narrow synthetic polymers of varying thermal stabilities.The analysis of PS reveals that as laser power is increased, the moments and the high mass bins increase to a maximum. This may be due to more high mass polymer desorption at higher laser powers. As laser energy is increased, fragmentation begins to occur, causing a decrease in the polymer moment and the high mass bins. The analysis of the bins of PEG reveals that the polymer sample is fragmenting, and more fragmentation is seen as laser power is increased. The PMMA analysis shows that as laser power is increased, the high mass bins are increasing. This is due to increased desorption of the high mass polymer molecules as laser power is increased.
Proceedings Title
49th ASMS Conference on Mass Spectrometry and Allied Topics
Volume
42(2)
Conference Dates
May 27-31, 2001
Conference Location
Chicago, IL
Conference Title
Mass Spectrometry and Allied Topics Conference

Keywords

laser energy, MALDI-TOF-MS, mass spectrometry, snythetic polymers

Citation

Wetzel, S. , Guttman, C. and Flynn, K. (2001), The Influence of Laser Energy of MALDI on the Molecular Mass Distribution of Synthetic Polymers, 49th ASMS Conference on Mass Spectrometry and Allied Topics, Chicago, IL, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851893 (Accessed April 21, 2024)
Created April 30, 2001, Updated October 12, 2021