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Investigation of Two Broad Features Often Observed in MALDI Mass SPectra of Synthetic Polymers



R J. Goldschmidt, Charles M. Guttman


The origins of two broad, unresolved features often observed in MALDI mass spectra of synthetic polymers are investigated. One occurs in the lower mass regions of mass spectra and is due to matrix cluster species. A wide variety of such clusters are apparently formed, and they are observed to have a strong tendency to decay. The other feature appears under the polymer peak envelope. Although various effects could contribute to such a feature, the primary cause is found to be a variety of polymer-matrix adducts. These also exhibit a tendency to decay. Since this feature distorts the representation of the polymer distribution, it should be removed during baseline correction prior to determination of molecular mass. Certain instrumental and sample preparation factors can affect the intensity of the broad features, but clusters, adducts and their decay appear to be inherent characteristics of MALDI. The observations here are consistent with the view that numerous small, charged clusters are released upon desorption in MALDI, and then proceed to decay to the ions observed in mass spectra. This does not rule out that some clusters, adducts, and cationized analyte molecules form as a result of combination during expansion.
ASMS Conference on Mass Spectrometry and Allied Topics


adducts, baseline correction, MALDI, poly(ethylene glycol), poly(methylmethacrylate), polystyrene


Goldschmidt, R. and Guttman, C. (2001), Investigation of Two Broad Features Often Observed in MALDI Mass SPectra of Synthetic Polymers, ASMS Conference on Mass Spectrometry and Allied Topics, [online], (Accessed July 21, 2024)


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Created January 1, 2001, Updated February 17, 2017