Infrared and Ultraviolet Matrix-Assisted Laser Desorption in a Quadrupole Ion Trap

该项目由分析和表面化学项目支持，研究四极离子阱中的离子分子化学。这项研究的目标是发展对离子分子化学的理解，因为它适用于大型有机分子的质谱分析，最终是含碳水化合物的抗生素。最初的工作将集中在激光解吸相关分子进入四极离子阱。取代基对离子阱中随后的双分子离子-分子反应的影响将被探索，以期利用这些反应来识别大型复杂有机分子的结构。碳水化合物是生物系统中极其重要的分子，但确定它们的结构是非常困难的，特别是因为它们通常不能结晶以进行x射线结构研究。质谱法测定结构也很困难，因为许多有趣的碳水化合物很难蒸发，而且质谱法是一种气相技术。本课题将采用激光解吸法将碳水化合物等大分子有机分子置于气相中，并根据结构分析的需要，采用可控离子-分子反应化学将大分子用质谱法切割成碎片。

This project, supported by the Analytical and Surface Chemistry Program, examines ion-molecule chemistry in the quadrupole ion trap. The goal of the research is to develop an understanding of ion-molecule chemistry as it applies to the mass spectrometric analysis of large organic molecules, eventually carbohydrate-containing antibiotics. Initial work will concentrate on the laser desorption of relevant molecules into the quadrupole ion trap. Substituent effects on the subsequent bimolecular ion-molecule reactions in the ion trap will be explored, with a view to exploiting these reactions for structural identification of large, complex organic molecules. %%% Carbohydrates are extremely important molecules in biological systems, but the determination of their structures is very difficult, especially because they usually cannot be crystallized for X-ray structural studies. Determination of structures by mass spectrometry is also difficult, since many interesting carbohydrates are very difficult to vaporize, and mass spectrometry is a gas phase technique. In this research project laser desorption methods will be used to place carbohydrates and other large organic molecules in the gas phase, and controlled ion-molecule reaction chemistry will be used to cut the large molecules into fragments by mass spectrometry, as required for structural analysis.