Abstract:
With the advent of soft ionization techniques such as electrospray (ESI) and matrix-assisted laser desorption/ionization (MALDI) to produce intact gas-phase ions from nonvolatile macromolecules, mass spectrometry has become an essential technique in the field of polymeric materials. However, (co)polymers of very high molecular weight or with reticulated architectures still escape ESI or MALDI, mainly due to solubility issues. Strategies developed to tackle such an analytical challenge all rely on sample degradation to produce low-mass species amenable to existing ionization methods. Yet, chain degradation needs to be partial and controlled to generate sufficiently large species that still contain topological or architectural information. The present article reviews the different analytical degradation strategies implemented to perform mass spectrometry of these challenging synthetic polymers, covering thermal degradation approaches in sources developed in the 2000s, off-line sample pre-treatments for controlled chemical degradation of polymeric substrates, and most recent achievements employing reactive ionization modes to perform chemolysis on-line with MS.
摘要:
随着软电离技术的出现,例如电喷雾(ESI)和基质辅助激光解吸/电离(MALDI),可从非挥发性大分子中产生完整的气相离子,质谱技术已成为聚合物材料领域的一项重要技术。然而,具有非常高分子量或具有网状结构的(共)聚合物仍然可以逃脱ESI或MALDI,主要是由于溶解度问题。为应对这种分析挑战而开发的策略都依赖于样品降解来产生适合现有电离方法的低质量物质。然而,链退化需要是部分的和控制的,以产生足够大的物种,仍然包含拓扑或架构信息。本文回顾了为对这些具有挑战性的合成聚合物进行质谱分析而实施的不同分析降解策略,涵盖了2000年代开发的源中的热降解方法,离线样品预处理,用于控制聚合物基材的化学降解,以及采用反应电离模式与MS在线进行化学分解的最新成就。