Date of Award
2023
Document Type
Open Access Dissertation
Degree Name
Doctor of Philosophy in Chemistry (PhD)
Administrative Home Department
Department of Chemistry
Advisor 1
Lynn R. Mazzoleni
Advisor 2
Sarah A. Green
Committee Member 1
Patricia A. Heiden
Committee Member 2
Laura E. Brown
Abstract
Biomass combustion contributes a large amount of aerosol particles to the atmosphere impacting the climate system and human health. Identifying the molecular composition of biomass burning organic aerosol (BBOA) is challenging because of its complex nature. Liquid chromatography mass spectrometric non-targeted screening (NTS) methods provide a comprehensive analysis. However, the instrumentation and data analysis are challenging due to the extreme complexity of environmental samples. In the first part of this study, we implemented a new LC/FT-MS data processing approach by combining existing open-source data processing tools, MZmine2.53 and MFAssignR. The method's validity was checked using the standard polyacrylic acid (PAA) mixture. Then the approach was implemented to analyze BBOA with commercial liquid smoke as a surrogate. Our approach significantly improves the molecular identification of BBOA by successfully resolving the limitations of LC/FT-MS data analysis. Further, the results were consistent with the more robust direct infusion FT-MS method, confirming that it demonstrates a significant advance in obtaining structural and semi-quantitative information about the molecular level composition of biomass combustion aerosol. Mimicking ambient BBOA is one of the significant challenges scientists face in atmospheric science. Therefore, in the second part of the study, we improve liquid smoke to simulate the BBOA by mixing them with different environmental additives. We found that those additives further enhance the chemistry of liquid smoke to match ambient BBOA. This could significantly impact aerosol research as it provides an option for environmentally relevant lab studies. Laboratory studies of BBOA frequently generate fresh smoke. However, it is less reproducible, expensive, and impracticable to perform in many lab conditions. Therefore, the capability of using commercial liquid smoke (without chemical alteration) as a fresh BBOA surrogate was studied in the next part of this dissertation compared with the laboratory-generated fresh smoke. According to the comparison, over 90% spectral abundance of fresh smoke and commercial liquid smoke matched each other, confirming that commercial liquid smoke is a better, inexpensive, and readily available surrogate for BBOA studies.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Divisekara, D.M.R. Thusitha Dinusha Kumarihami, "UHPLC/FT-MS NON-TARGETED SCREENING APPROACH FOR BIOMASS BURNING ORGANIC AEROSOL AND LIQUID SMOKE AS BIOMASS BURNING ORGANIC AEROSOL SURROGATE", Open Access Dissertation, Michigan Technological University, 2023.