Ion Trap and Hybrid Mass Spectrometry: Instrumentation and Applications

本项目属于分析化学和表面化学的一般领域以及质谱和表面科学的子领域。这个广泛的实验推力的统一主题是开发新的质谱仪器及其在解决痕量分析和材料表征中的挑战性问题中的利用。本项目正在处理两个相关的分领域。一种侧重于研究低能离子与表面的相互作用。它试图详细描述电荷转移、解离和反应现象，当相对低能量的单原子和多原子离子撞击金属和分子固体表面时发生。为了进行这些研究，Cooks教授和他的学生正在建造一种新的混合质谱仪，可以对这些表面过程中涉及的反应物和产物离子进行质量、角度和动能选择。该仪器还允许通过低能离子沉积和高能离子冲击来研究表面的化学改性。第二个子领域侧重于另外两种新型质谱仪器的开发、表征和应用，一种离子阱质谱仪和一种磁电混合质谱仪。通过这两种仪器，碰撞激活解离、光电离、光解离和离子-分子反应技术将用于研究远程位点断裂现象、气相解离过程的热力学与动力学控制、双电荷离子作为化学电离试剂的使用、激发态在小全氟离子解离中的作用，以及高能高价物质的形成和反应化学。这项研究将导致新的质谱仪器的发展和改进，灵敏的化学表征方法。此外，这项工作应引起美国技术在质谱领域的持续重申。这是目前特别感兴趣的，因为质谱世界市场上的主要商业公司目前在英国和日本。预计在未来几年内，库克斯教授和其他NSF受助者实验室的技术将有效转移到美国制造商，这将显著改变这一局面。

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.