Ion Trap and Hybrid Mass Spectrometry: Instrumentation and Applications

该项目属于分析和表面化学的一般领域，以及质谱学和表面科学的子领域。这一广泛实验的统一主题是开发新的质谱仪，并将其用于解决痕量分析和材料表征中的挑战性问题。该项目涉及两个相关的分领域。其中一个重点是研究低能离子与表面的相互作用。它试图详细说明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的电荷转移、解离和反应现象。为了进行这些研究，Cooks教授和他的学生正在建造一种新型的混合质谱仪，能够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。该仪器还可以研究低能离子沉积和高能离子撞击对表面的化学修饰。第二个分区集中于另外两个新的质谱仪的开发、表征和应用，即离子陷阱质谱计和磁电混合扇形机。在这两台仪器上，碰撞激活解离、光电离、光解和离子-分子反应技术将被用来研究远位碎裂现象、气相解离过程的热力学和动力学控制、双电荷离子作为化学电离剂的使用、激发电子态在小的全氟离子解离中的作用以及高能高价物种的形成和反应化学。这项研究将导致新的质谱学仪器的发展和改进的、灵敏的化学表征方法。此外，这项工作应该会促使美国技术在质谱学领域继续得到重申。这一点目前特别令人感兴趣，因为质谱学世界市场上的主要商业公司目前在英国和日本。预计从库克斯教授和其他NSF受赠者的实验室向美国制造商高效转移技术，可能会在未来几年内显著改变这一局面。

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.