Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA.
Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA.
Anal Chim Acta. 2019 Jan 24;1047:104-114. doi: 10.1016/j.aca.2018.09.068. Epub 2018 Oct 3.
The prospect of developing new bio-based products from lignin partially depends on the development of effective analytical techniques to characterize the end products from lignin degradation experiments. To date, the most utilized mass spectrometric technique for characterizing lignin oligomers has been negative ion mass spectrometry. Positive ion mass spectrometry remains a relatively unexplored approach for lignin sequencing. Here we report on the sequencing of lignin oligomers using lithium cationization positive ion electrospray followed by higher-energy collisional dissociation (HCD) tandem mass spectrometry on a high-resolution accurate-mass Orbitrap mass spectrometer. Thirteen synthetic lignin model oligomers containing β-O-4 and 4-O-α linkages were analyzed and sequenced based on their HCD tandem mass spectrometry fragmentation patterns. Proposed sequence-specific fragmentation pathways are provided. The method presented in this study provides a potential application of lithium cationization tandem mass spectrometry for the analysis of lignin degradation products.
从木质素中开发新的生物基产品的前景在一定程度上取决于开发有效的分析技术来对木质素降解实验的最终产物进行特征描述。迄今为止，用于木质素低聚物特征描述的最常用的质谱技术一直是负离子质谱。对于木质素测序，正离子质谱仍然是一种相对未被探索的方法。在此，我们报告了使用锂离子化正离子电喷雾，然后在高分辨率精确质量轨道阱质谱仪上进行更高能量碰撞解离（HCD）串联质谱，对木质素低聚物进行测序的方法。分析了十三种含有β-O-4 和 4-O-α 键的合成木质素模型低聚物，并根据它们的 HCD 串联质谱碎裂模式进行了测序。提供了建议的序列特异性碎裂途径。本研究中提出的方法为木质素降解产物的锂离子化串联质谱分析提供了一种潜在的应用。
