Molecular Level Characterization of Dissolved Organic Matter Integrating Trapped Ion Mobility Spectrometry and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Authors

Dennys Leyva Bombuse, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Chemistry

First Advisor's Name

Francisco Fernandez Lima

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Piero Gardinali

Second Advisor's Committee Title

Committee member

Third Advisor's Name

John Berry

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Rudolf Jaffé

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Joong Ho Moon

Fifth Advisor's Committee Title

Committee member

Sixth Advisor's Name

John Kominoski

Sixth Advisor's Committee Title

Committee member

Keywords

DOM, TIMS, FT-ICR MS, isomers, Graph-DOM, structural network

Date of Defense

7-1-2022

Abstract

Dissolved organic matter (DOM) is an extremely complex mixture of organic molecules ubiquitous in aquatic systems and a critical component of the global carbon cycle. Little is known about DOM structural composition at the molecular level. The work presented in this dissertation summarizes the development of a novel analytical toolbox based on trapped ion mobility spectrometry and Fourier transform ion cyclotron resonance mass spectrometry (TIMS-FT-ICR MS) that has significantly contributed to expand our knowledge of DOM molecular complexity and diversity. The TIMS-FT-ICR MS/MS analysis provided for the first-time lower and upper estimation of the molecular isomeric diversity. The TIMS-FT-ICR MS/MS methodology was further developed to allow for chemical formula-based isomeric and neutral loss fragmentation structural description and database validation. This novel procedure enabled the unambiguous assignment of candidate isomeric structures based on accurate mass, database MS/MS matching scores, and ion mobility. A fast and routine structural characterization DOM workflow method was developed: GraphDOM. The method utilizes neutral loss fragmentation patterns acquired using continuous accumulation of selected ions (CASI)-collision induced dissociation (CID) FT-ICR MS/MS. The neutral mass loss patterns are used to define structural families leading to the identification and visualization of the DOM transformational processes. The GraphDOM methodology was successfully applied to the characterization of DOM along a salinity transect of the Harney River, Florida Everglades. The GraphDOM method was further implemented with isomeric content description at the molecular level and applied to four common aquatic systems. The application of the GraphDOM methodology allowed for the first time identification of common and unique DOM transformational networks across aquatic ecosystems.

Identifier

FIDC010826

ORCID

https://orcid.org/0000-0003-0731-6182

Previously Published In

1. Leyva, D.; Tariq, U.; Saeed, F.; Jaffé, R.; Fernandez-Lima, F. Unsupervised structural classification of Dissolved Organic Matter based on fragmentation pathways. Environ. Sci. Technol. 2022, 56 (2), 1458-1468.
2. Leyva, D.; Jaffé, R.; Fernandez-Lima, F. Structural Characterization of Dissolved Organic Matter at the Chemical Formula Level Using TIMS-FT-ICR MS/MS. Anal. Chem. 2020, 92 (17), 11960-11966.
3. Leyva, D.; Tose, L. V.; Porter, J.; Wolff, J.; Jaffé, R.; Fernandez-Lima, F. Understanding the structural complexity of dissolved organic matter: isomeric diversity. Faraday Discuss. 2019, 218 (0), 431-440.

Recommended Citation

Leyva Bombuse, Dennys, "Molecular Level Characterization of Dissolved Organic Matter Integrating Trapped Ion Mobility Spectrometry and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry" (2022). FIU Electronic Theses and Dissertations. 5103.
https://digitalcommons.fiu.edu/etd/5103