Ion Trap and Hybrid Mass Spectrometry: Instrumentation and Applications

点击翻译按钮获取中文摘要

This project is in the general area of analytical and surface chemistry and in the subfields of mass spectrometry and surface science. The unifying theme of this broad experimental thrust is the development of new mass spectrometry instrumentation and its exploitation in the solution of challenging problems in trace analysis and materials characterization. Two related subareas are being addressed in this project. One focusses on the study of the interactions of low energy ions with surfaces. It seeks to detail the charge transfer, dissociation, and reaction phenomena that occur when relatively low energy monatomic and polyatomic ions strike the surfaces of metals and molecular solids. In order to carry out these studies, Professor Cooks and his students are building a new hybrid mass spectrometer that enables mass, angle, and kinetic energy selection of both reactant and product ions involved in these surface processes. This instrument also permits investigation of the chemical modification of surfaces by low energy ion deposition and high energy ion impact. The second subarea focusses on the development, characterization, and application of two other new mass spectrometry instruments, an ion trap mass spectrometer and a hybrid magnet and electric sector machine. With these two instruments, collision-activated dissociation, photoionization, photodissociation, and ion-molecule reaction techniques will be used to study phenomena of remote site fragmentation, thermodynamic vs kinetic control of gas phase dissociation processes, the use of doubly charges ions as chemical ionization reagents, the role of excited electronic states in the dissociation of small perfluorinated ions, and the formation of and reaction chemistry of energetic hypervalent species. This research will lead to the development of new mass spectrometric instrumentation and to improved, sensitive methods of chemical characterization. Additionally, this work should give rise to the continued reassertion of U.S. technology in the area of mass spectrometry. This is of particular interest at present inasmuch as the leading commercial firms in the mass spectrometry world market are currently in the United Kingdom and in Japan. It is expected that the efficient transfer of technology from the laboratories of Professor Cooks and other NSF grantees to U.S. manufacturers could significantly alter this picture in the next few years.