Size Dependence of the Folding of Multiply Charged Sodium Cationized Polylactides Revealed by Ion Mobility Mass Spectrometry and Molecular Modelling
✍ Scribed by Dr. Julien De Winter; Dr. Vincent Lemaur; Dr. Renaud Ballivian; Dr. Fabien Chirot; Dr. Olivier Coulembier; Dr. Rodolphe Antoine; Dr. Jérôme Lemoine; Dr. Jérôme Cornil; Prof. Philippe Dubois; Dr. Philippe Dugourd; Dr. Pascal Gerbaux
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 936 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0947-6539
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✦ Synopsis
Abstract
Ion mobility spectrometry coupled with mass spectrometry was used to experimentally determine the three‐dimensional structure of multiply charged sodium cationized polylactides (PLA). In particular, the experiments were conducted to evaluate the influence of the charge state and the size on the gas‐phase conformation of cationized PLA. The measured collision cross sections were then compared to calculated values obtained by computational chemistry methods. The most striking feature was the experimental and theoretical observation of a breaking point in the quasilinear relationship between the average collision cross sections and the number of monomer units for the triply charged cations. This breaking point was theoretically demonstrated, for the doubly and triply charged cations, to be associated with a significant folding of the polymer chains around the cationizing agents. The occurrence of such breaking points could be exploited to correlate the charge state of the most intense ion series observed upon electrospray ionization with the number‐average molecular mass of a polymer.