Applications of mass spectrometry in C-C activation and analysis of hydrocarbons, process chemistry and ion-surface interactions
Abstract
Ions used to be generated in high vacuum only with a few methods such as electron impact (EI), chemical ionization (CI), and field ionization/field desorption (FI/FD). The emergence of atmospheric pressure ionization, especially electrospray ionization (ESI), not only greatly extends the range of analytes that can be analyzed by mass spectrometry (MS), but also greatly enhances the MS flexibility due to the separation of sample ionization from high vacuum mass analyzer and detector. More recently, ambient ionization, a special category of atmospheric pressure ionization, pioneered with desorption electrospray ionization (DESI) technique, minimizes sample pretreatment and makes sample analysis more convenient and quicker. The first part of the thesis focuses on developing new ionization methods for mass spectrometric analysis in atmospheric pressure. In this work, a new strategy for hydrocarbon functionalization by insertion of a nitrogen atom into C-C bonds was developed. In the second part of the thesis, several ambient ionization methods were used for optimization of chemical processes and reaction monitoring. A new water-based reaction system for reductive amination, was developed with overwhelming advantages over typical methanol-based system. Two reaction monitoring systems based on transmission-mode DESI and inductive electrospray ionization were successfully developed, the imine formation and the subsequent imine reduction were able to be monitored. In the third part of the thesis, ion/surface interactions were studied through ion soft landing (SL). In situ secondary ion mass spectrometry (SIMS) was used to monitor SL-modified surfaces; a new matrix-enhanced SIMS method was developed; the neutralization of cations deposited on various substrates under strictly controlled atmosphere was investigated.
Degree
Ph.D.
Advisors
Cooks, Purdue University.
Subject Area
Chemistry|Organic chemistry
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.