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FOURIER TRANSFORM AND SECTOR MASS SPECTROMETRY FOR ACCURATE MASS MEASUREMENTS, PULSED SAMPLE HANDLING, MULTIPHOTON IONIZATION, AND THE STUDY OF CYCLOPROPANE RADICAL CATIONS (DISTONIC IONS, FTMS, CAD)
Abstract
In Part 1, a generalized procedure for the statistical evaluation of accurate mass measurement quality is presented. A statistically sig- nificant number of mass spectra of a test compound are acquired, and the mass measurement errors for these spectra are rigorously evaluated using statistical techniques to provide a quantitative assessment of mass spectrometer performance. Application of this method to the determination of the effects of various oper- ating parameters on mass measurement quality is demonstrated. In Part 2, the role of the Fourier transform mass spectrometer (FTMS) in analytical chemistry is explored by the development of new methods and the evaluation of its performance. We describe the use of pulse valves in FTMS to introduce reagent gases for chemical ionization or ion-molecule reactions and as a GC/FTMS interface. The pulse valve inlet is demonstrated to yield resolution and sensi- tivity enhancements over the corresponding static pressure experi- ments as well as temporally resolving experimental events in FTMS. Multiphoton ionization (MPI) is explored as a selective ionization technique for GC/FTMS. The selectivity, sensitivity, resolution, and mass measurement accuracy afforded by such a combination are all shown to be either competitive with or superior to those exhibited by the previously demonstrated GC/MPI-time-of-flight system. Finally, the performance of FTMS is compared to a conventional double-focussing mass spectrometer with respect to the quality of their high resolution mass spectra. This comparison serves to establish the performance characteristics of the FTMS at the present time. Part 3 includes a description of experimental excursions into the chemistry of the cyclopropane radical cation. By using collision activated dissociation (CAD) and specific ion-molecule reaction chemistry, it is shown that the cyclopropane radical cation ring- opens to form the trimethylene radical cation. The reaction of cyclopropane radical cations with ammonia is also explored in this Part, and is shown by CAD spectrometry to yield the distonic product ions, CH(,2)NH(,3)('+) and CH(,2)CH(,2)CH(,2)NH(,3)('+).
Subject Area
Analytical chemistry
Recommended Citation
SACK, THOMAS MICHAEL, "FOURIER TRANSFORM AND SECTOR MASS SPECTROMETRY FOR ACCURATE MASS MEASUREMENTS, PULSED SAMPLE HANDLING, MULTIPHOTON IONIZATION, AND THE STUDY OF CYCLOPROPANE RADICAL CATIONS (DISTONIC IONS, FTMS, CAD)" (1985). ETD collection for University of Nebraska-Lincoln. AAI8516881.
https://digitalcommons.unl.edu/dissertations/AAI8516881