Polymeromics : structural elucidation of macromolecules via tandem mass spectrometry utilizing various ionization techniques
The main objective of the presented thesis was to investigate the applicability of mass spectrometry (MS)-based techniques for the analysis of polymers. A variety of MS and tandem MS (MS/MS) techniques were utilized to gain accurate structural information from intricate macromolecular structures and to achieve the fragmentation behavior of several synthetic polymer classes such as various poly(2-oxazoline)s (POx), poly(ethylene imine)s (PEI), and poly(methyl acrylate)s (PMA). MS techniques was used to gain information about their molar mass distributions, PDI values, monomer units, macromolecular architectures, side chain substituents and end-group functionalities. ESI, APCI and MALDI MS were utilized in order to comprehensively analyze synthetic polymers in systematic comparison studies. Additional information about the fragmentation behavior and the stabilities of macromolecules were gained from energy-dependent CID experiments. Survival yield (SY) method was applied to several polymers for the first time and SY curves were shown as a useful tool to correlate the macromolecular structure of polymers to their fragmentation behavior. Moreover, energy dependent CID experiments were also performed successfully to analyze the gas-phase stabilities of various metal complexes. The relative complex stabilities were estimated depending on the nature of the coordinated ligands used in the synthesis of investigated metal complexes. The hyphenation of LC and MS techniques for comprehensive polymer characterization was shown for the case of poly(2-ethyl-2-oxazoline)s (PEtOx). The characterization of PEtOx copolymers were accomplished by the coupling of a two dimensional chromatography (2D) technique (LCCC x SEC) to MS and MS/MS techniques. An important approach for the evaluation of the MSn data by a special interpretation software was described and the field of “Polymeromics” was introduced in detail with a number of examples.