Asare Shardrack O, Lynn Bert C
Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA.
J Mass Spectrom. 2019 Jun;54(6):540-548. doi: 10.1002/jms.4365.
Electrospray ionization mass spectrometry has recently become the technique of choice for rapid characterization of lignin degradation products. However, the fundamental question of the relationship between lignin structure and ionization efficiency has not been explored. In this work, we studied the electrospray ionization response of five structurally similar β-O-4' model lignin compounds using lithium cationization in the positive electrospray ionization mode. The studied compounds have the same β-O-4' backbone structure but differ at the α-position by increasing nonpolar side chains. Our results show a correlation between the ionization response and the length of the nonpolar side chain, with analytes having the longest side chain recording the highest ESI response in the full scan mode. Factors affecting the formation of analyte ions and analyte cluster ions were also studied. We have shown for the first time in this work that the introduction of a nonpolar group onto a β-O-4' lignin compound can increase the lithium cationization ESI response in the positive ion mode.
电喷雾电离质谱法最近已成为快速表征木质素降解产物的首选技术。然而，木质素结构与电离效率之间关系的基本问题尚未得到探讨。在这项工作中，我们在正电喷雾电离模式下使用锂阳离子化研究了五种结构相似的β-O-4'模型木质素化合物的电喷雾电离响应。所研究的化合物具有相同的β-O-4'主链结构，但在α位因非极性侧链增加而有所不同。我们的结果表明电离响应与非极性侧链长度之间存在相关性，在全扫描模式下，具有最长侧链化学物的ESI响应最高。还研究了影响分析物离子和分析物簇离子形成的因素。我们在这项工作中首次表明，在β-O-4'木质素化合物上引入非极性基团可以增加正离子模式下的锂阳离子化ESI响应。
