Dissertations and Theses @ UNI
Availability
Open Access Thesis
Keywords
Ionization; Time-of-flight mass spectrometry; Academic theses;
Abstract
Laser desorption has been an important tool in mass spectrometry. It has been known that an order of magnitude more neutrals than ions are produced during laser desorption. A Time-Of-Flight Mass Spectrometer with an infinitely adjustable acceleration region was constructed to map the population distribution of neutral ion precursors and metastable ions in the flight tube. Desorption was performed by using a nitrogen UV laser at 337 nm. Experiments conclude that the majority of post-source ionization of neutrals occurs approximately 2.5 cm from the sample-laser interface. The intensity of ions tapers rapidly out to 6.0 cm, however ions were detected as far as 17.0 cm from the sample interface. The calculated field free drift rate of sodium and cesium neutral precursors is consistent with prior research, and kinetic energy screening of the ions show that cesium ions have a lower kinetic energy than cesium iodide clusters. This gives evidence to the meta-stable decay of cesium iodide neutral precursors after ionization. These studies provide additional insight into the kinetics of ion formation and fragmentation during laser desorption. Additional research could yield evidence of the rate of formation of ions from neutral precursors.
Year of Submission
2012
Degree Name
Master of Science
Department
Department of Chemistry and Biochemistry
First Advisor
Curtiss D. Hanson
Second Advisor
R. Martin Chin
Third Advisor
Jeffrey Elbert
Date Original
2012
Object Description
1 PDF file (108 leaves)
Copyright
©2012 David S. Ames
Language
en
File Format
application/pdf
Recommended Citation
Ames, David S., "A Novel Method of Studying Ion Formation and Fragmentation Using a Modified Time-of-Flight Mass Spectrometer" (2012). Dissertations and Theses @ UNI. 1930.
https://scholarworks.uni.edu/etd/1930
Comments
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