Crude Oil Characterization using Gas Chromatography, Ion Mobility Spectrometry and Mass Spectrometry

Authors

Clement A. Olanrewaju, 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

Kevin E. O'Shea

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Martin E. Quirke

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Krishnaswamy Jayachandran

Fifth Advisor's Committee Title

Committee member

Keywords

Crude oil, PAHs, PASH, APLI, APPI, ESI, ionization source, gas chromatography, ion mobility spectrometry, mass spectrometry

Date of Defense

6-1-2022

Abstract

The characterization of crude oils at the compositional level remains challenging due to their high chemical complexity and isomeric diversity. The present work expands the analytical separation space of chemical components in crude oils by coupling gas chromatography (GC), trapped ion mobility spectrometry (TIMS), and mass spectrometry (GC-TIMS-MS and TIMS-FT-ICR MS) for the effective separation and identification of isomeric compounds. The coupling of GC and TIMS-MS platform enhanced the peak capacity and showed complementary isomeric separation. The combination of GC-TIMS-MS and GC-EI-MS technique provided a comprehensive characterization of PAHs and similar compounds from crude oils on the basis of retention data, ion mobility, accurate mass, isotopic pattern distribution, ion mobility-based theoretical candidate assignment, electron ionization (EI) fragmentation patterns and database search together with reference standards. The possibility of both targeted and untargeted screening of isomeric and isobaric species was demonstrated with additional characterization metrics not available in traditional GC-EI-MSⁿ workflows. The identified PAH compounds (including 16 Environmental Protection Agency targets) showed signature patterns across four deasphalted crude oils. The differences in the PAH concentration ratio enabled to determine thermal maturity, lithology, and microbial contribution to each oil formation. For the first time, an exhaustive list of GC-accessible compounds, characterized by RT, CCS, m/z, chemical formula, and peak area were used to differentiate crude oils from different origin. The use of different atmospheric pressure ionization sources and polarity ion mode added another degree of specificity by discriminating molecular chemical class compounds based on isomeric content at chemical formulae level. Lastly, photooxidation products of PAH and PASH were separated and identified by chemical formulae and mobility value.

Identifier

FIDC010724

ORCID

0000-0003-0140-9097

Comments

This is the updated version.

Previously Published In

Olanrewaju, C. A., Ramirez, C. E., & Fernandez-Lima, F. (2021). Comprehensive Screening of Polycyclic Aromatic Hydrocarbons and Similar Compounds Using GC–APLI–TIMS–TOFMS/GC–EI–MS. Analytical Chemistry, 93(15), 6080-6087.

Olanrewaju, C. A., Ramirez, C. E., & Fernandez-Lima, F. (2021). Characterization of Deasphalted Crude Oils Using Gas Chromatography–Atmospheric Pressure Laser Ionization–Trapped Ion Mobility Spectrometry–Time-of-Flight Mass Spectrometry. Energy & Fuels, 35(17), 13722-13730.

Recommended Citation

Olanrewaju, Clement A., "Crude Oil Characterization using Gas Chromatography, Ion Mobility Spectrometry and Mass Spectrometry" (2022). FIU Electronic Theses and Dissertations. 5073.
https://digitalcommons.fiu.edu/etd/5073