Graduation Year
2020
Document Type
Dissertation
Degree
Ph.D.
Degree Name
Doctor of Philosophy (Ph.D.)
Degree Granting Department
Chemistry
Major Professor
Theresa Evans-Nguyen, Ph.D.
Committee Member
Andreas Muller, Ph.D.
Committee Member
Abdul Malik, Ph.D.
Committee Member
Xiaopeng Li, Ph.D.
Keywords
Quadrupole Ion Trap, Digital Ion Trap, Static Buffer Gas Introduction, Pulsed Buffer Gas Introduction, Isotope Ratio Mass Spectrometry, Selective Isotope Enrichment, Electron Impact Ionization, Chemical Ionization, Mass Selective Instability, Resonance Ejection
Abstract
Ion trap mass spectrometers present a powerful analytical tool which not only enables mass spectrometric determination of analyte species but also has the added feature of being able to act as an ion storage device. As a mass spectrometer, ion traps can achieve a reasonable mass range with flexible mass resolution while boasting a considerably smaller footprint when compared to conventional time-of-flight or magnetic sector instruments. Due to their smaller geometries, high-pressure tolerance, and ability to perform tandem mass spectrometry, ion trap mass spectrometers are ideal candidates for portable applications such as deployment to another planetary body. While ideal candidates for portable applications, ion traps are limited in the number of ions they can store due to space charge effects that arise from ion-ion repulsions thereby limiting the utility of these instruments. Additionally, effects of size, weight and power must also be considered when developing a portable instrument. For the following chapters, the focus will be on the optimization of an ion trap mass spectrometer for the targeted application of isotope ratio mass spectrometric measurements of xenon. Initially, a novel means of improving resolution and total ion signal through precision control of the buffer gas introduction was developed. We then explored how the data acquisition system can be modified to improve accuracy and precision in our isotope ratio measurements. Finally, a method of selective enrichment and chemical ionization was studied to determine if xenon could be selectively extracted over other atmospheric gases and chemically ionized using argon as a reagent gas.
Scholar Commons Citation
Vazquez, Timothy, "Optimization of a Digital Ion Trap to Perform Isotope Ratio Analysis of Xenon for Planetary Studies" (2020). USF Tampa Graduate Theses and Dissertations.
https://digitalcommons.usf.edu/etd/9005
