(Georgia Institute of Technology, 2021-08-19)
Mckenna, Kristin Ruth
The origin and prebiotic functions of carbohydrates are not well characterized. Limitations in analytical methodology to analyze the regio- and stereochemistry of carbohydrates in complex mixtures exacerbates this problem. Several ion mobility-tandem mass spectrometry techniques were developed to study model prebiotic carbohydrate reactions. Covalent derivatization with 3-carboxy-5-nitrophenylboronic acid (3C5NBA) was determined to improve these characterizations and allow for more complete structural analysis by tandem mass spectrometry. Cyclic ion mobility spectrometry improved the ability to distinguish four monosaccharide and eight disaccharide isomers as their 3C5NBA derivatives. Organic acids were also analyzed for their potential to improve carbohydrate separations as noncovalent modifiers. The optimal organic acid modifiers were determined to be L-malic acid and N-methyl-D-aspartic acid, which were further characterized through a more sensitive, Fourier transform-based ion mobility method.
(Georgia Institute of Technology, 2021-07-28)
Zambrzycki, Stephen C.
The development of new rapid screening tools and the assessment of current technologies helps explore new realms of chemistry and ensure the quality of chemical products. Mass spectrometry is a powerful analytical tool that measures the mass-to-charge ratio of ionized analytes. Two new ambient plasma ionization tools were developed to rapidly ionize samples for mass spectrometry. Portable and high-throughput mass spectrometry was also evaluated for its performance in pharmaceutical and cellular therapy quality screening.
In Part 1 of this thesis, new tools were developed for Vacuum-assisted Plasma Ionization (VaPI). First, VaPI was built for the Waters Synapt G2S, an ion mobility mass spectrometer. Then, an aerosolizer and a scanning mobility particle size analyzer was coupled to the VaPI source to create Aero-VaPI. Simultaneous acquisition of the aerosol diameter, ion mobility, and mass-to-charge with Aero-VaPI illustrates the breadth of information that can be acquired in real time for simulated pre-biotic aerosol chemistries. A pyrolysis device was also built for VaPI to rapidly screen and characterize pyrolyzed polymers such as nylons. The combination of measurements in pyrolysis temperature, ion mobility, and mass-to-charge show how new potential molecular structures of pyrolyzed nylons were discovered.
In Part 2 of this thesis, portable mass spectrometry was evaluated alongside 11 other portable tools for the rapid screening of small molecule pharmaceuticals. The pros and cons of each device were noted. The Waters QDa mass spectrometer had the highest sensitivities in the study, but it was not deemed suitable for field testing due to its resource requirements and mechanical complexity. Finally, a workflow was developed for matrix assisted laser desorption ionization (MALDI) mass spectrometry to rapidly assess the quality of cellular therapies. Preliminary data was acquired to demonstrate the speed and automation of the MALDI and data processing workflow for cellular therapy quality screening.
(Georgia Institute of Technology, 2021-01-19)
Huang, Danning
Mass Spectrometry (MS) is the most commonly used technology in metabolomics studies. The high sensitivity of MS enables the detection of low abundance metabolites that are below the detection threshold of other analytical platforms, and high resolution greatly reduces spectral overlaps. When coupled with separation techniques, such as ultra- performance liquid chromatography (UPLC), spectral complexity is greatly reduced and metabolic chemical properties can be revealed. Overall, MS-based non-targeted metabolomics allows the detection and identification of a wide range of metabolites with high sensitivity and high resolution.
In this thesis work, UPLC-MS based non-targeted metabolomics was used to investigate metabolic alterations and discover potential biomarkers for high-grade serous carcinoma (HGSC) and medulloblastoma (MB). The evaluation of two leading analytical platforms, Orbitrap ID-X and 12T solariX FT-ICR mass spectrometers, in mass accuracy and relative isotope abundance (RIA) measurements of 13C1 and 18O1, and how these affect the assignment of the correct elemental formulae was performed. In addition, a multi-omics approach was performed to discover candidate critical quality attributes (CQA) that are predictive of MSC immunomodulatory capacity.
Taken together, this thesis work has contributed meaningfully to the metabolomics field by discovering potential biomarkers for HGSC and MB diseases, providing the first comparison between high- resolution FT-ICR-MS and Orbitrap Tribrid MS platforms for elemental formulae annotation purposes. Furthermore, the thesis work also provides candidate CQAs that are predictive of MSC immunomodulatory capacity, bringing the potential to inform future manufacturing strategies. This multi-omics approach to CQA discovery can also be translated into other cell therapies.