表面辅助激光解吸电离-飞行时间质谱中多聚体离子产生规律的研究

发布时间：2018-05-06 17:06

  本文选题：表面辅助激光解吸电离飞行时间质谱 + 稠环芳烃　； 参考：《分析化学》2017年06期

【摘要】：表面辅助激光解吸电离质谱(SALDI-MS)已经成为固态、液态样品分析的重要手段,并且分析对象逐渐由生物大分子扩展到小分子。然而,对小分子电离微观反应机理的研究仍处于起步阶段。本研究选择3种分子结构相似的稠环芳烃化合物芘、六苯并苯、红荧烯作为研究对象,考察了这3种化合物激光电离产物的差异,并研究了激光能量对六苯并苯产物离子分布的影响。结果表明,观察到芘、六苯并苯多聚体离子产物,还观测到了六苯并苯失去C_2H_2的碎片离子峰;而没有观测到明显的红荧烯聚合物离子产物,只观测到了大量失去C6H5的碎片离子峰。最后,对3种不同化合物的激光电离微观机理进行了分析。由于芘、六苯并苯具有平面大π键,分子间的π-π键相互作用是产生多聚体离子的主要原因;而红荧烯的空间位阻削弱了分子间相互作用,从而阻碍了多聚体离子的形成。
[Abstract]:Surface assisted laser desorption ionization mass spectrometry (SALDI-MSMS) has become an important method for the analysis of solid and liquid samples, and the object of analysis is gradually extended from biological macromolecules to small molecules. However, the mechanism of ionization reaction of small molecules is still in its infancy. In this study, three structurally similar polycyclic aromatic compounds, pyrene, hexabenzobenzene and red fluorene, were selected to investigate the differences of laser ionization products of these three compounds. The effect of laser energy on the ion distribution of hexabenzobenzene products was studied. The results showed that pyrene, hexabenzobenzene polymer ion product, hexabenzobenzene loss fragment ion peak of C_2H_2 were observed, but no obvious red fluorene polymer ion product was observed. Only a large number of fragment ion peaks of C6H5 have been observed. Finally, the microscopic mechanism of laser ionization of three different compounds is analyzed. Due to pyrene, hexobenzobenzene has a large 蟺 bond, the 蟺-蟺 bond interaction between molecules is the main reason for the formation of polymer ions, while the steric hindrance of red fluorene weakens the intermolecular interaction, thus hindering the formation of polymer ions.
【作者单位】： 湖北工业大学材料与化学工程学院;中国科学院大连化学物理研究所分离分析化学重点实验室;
【基金】：国家自然科学基金项目(No.51572074)资助~~
【分类号】：O657.63;TQ241.5
，

本文编号：1853140