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

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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.