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Size Dependence of the Folding of Multiply Charged Sodium Cationized Polylactides Revealed by Ion Mobility Mass Spectrometry and Molecular Modelling
Author(s) -
De Winter Julien,
Lemaur Vincent,
Ballivian Renaud,
Chirot Fabien,
Coulembier Olivier,
Antoine Rodolphe,
Lemoine Jérôme,
Cornil Jérôme,
Dubois Philippe,
Dugourd Philippe,
Gerbaux Pascal
Publication year - 2011
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201100383
Subject(s) - chemistry , mass spectrometry , ion , ion mobility spectrometry , electrospray ionization , monomer , ionization , folding (dsp implementation) , polymer , sodium , electrospray , analytical chemistry (journal) , chemical physics , chromatography , organic chemistry , electrical engineering , engineering
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.