About

Cornelia Rasmussen is an Research Assistant Professor at the UT Institute for Geophysics. Her research interests include impact cratering, radiogenic and stable isotope geochemistry, and paleoecology. She is involved in studying geochemical processes related to planetary and Earth sciences, contributing to understanding the history and evolution of planetary surfaces and Earth's geological record.

Research topics

• Physics
• Chemistry
• Stereochemistry
• Chromatography
• Geology
• Materials science
• Biology
• Computer Science
• Organic chemistry
• Nuclear physics
• Environmental chemistry
• Astrobiology
• Environmental science
• Computational chemistry
• Biochemistry
• Geochemistry
• Nuclear magnetic resonance
• Seismology
• Paleontology
• Earth science
• Astronomy

Selected publications

• Opportunities and Limitations of Nuclear Magnetic Resonance Spectroscopy in Astrobiology

  ACS Earth and Space Chemistry · 2026-01-21

  article1st authorCorresponding

  For decades, nuclear magnetic resonance (NMR) spectroscopy has been utilized as a powerful tool in various scientific disciplines, most prominently in chemistry, to determine molecular structures or monitor reactions. While well established in various fields, NMR applications in astrobiology are still unclear. This work aims to explore the potential of NMR in astrobiology, highlighting strengths but also weaknesses. We illustrate the capabilities of NMR with two applications: (1) recently developed methods for position-specific carbon isotope analysis of complex organics; and (2) well-established tools for performing quantitative compositional analysis of complex organic mixtures. By utilizing samples relevant to astrobiology, specifically the amino acid valine and analogue mixtures of organics, we showcase that molecules retain a source-dependent and distinct intramolecular carbon isotope fingerprint. We demonstrate that compositional sample analysis provides an independent and complementary line of evidence pointing toward the origin of a molecule or mixture. Together, these NMR tools have the potential to support life detection efforts and aid in distinguishing between biotic and abiotic samples. Finally, we discuss sensitivity, detection limits, and the portability of NMR, and propose how integration with mass-spectrometry techniques will be imperative to enable more targeted and comprehensive analyses relevant to astrobiology, including in situ analysis, but also sample return missions.

  PublisherDOI

• Position-Specific Carbon Isotope Fingerprinting of Fluorinated Organics and Degradation Products

  Analytical Chemistry · 2026-03-10

  article1st author

  Fluorinated organic compounds are of growing environmental and forensic relevance due to their widespread use in pharmaceuticals, agrochemicals, and consumer products, their environmental persistence, and potential ecological and human health impacts. Elucidating their sources and transformation pathways is therefore a major focus of current research. Stable carbon isotope analysis provides a powerful approach for tracing molecular origins and linking parent compounds to degradation products. Recent isotope measurements have largely relied on mass-spectrometry techniques, which provide only an average isotope ratio across a compound. Here, we employ a novel nuclear magnetic resonance (NMR) spectroscopy tool to determine position-specific carbon isotope ratios (13C/12C) in organofluorine compounds and their degradation products. This approach enables isotope measurements without combustion or extensive purification and, crucially, resolves ratios at individual carbon positions rather than bulk averages. The resulting intramolecular isotope fingerprints are unique to a molecule’s source. Applied to selected pharmaceuticals and pesticides, these fingerprints allow discrimination of chemically identical compounds. Moreover, we show that the 13C/12C signature at the fluorinated carbon persists through degradation, demonstrated for lansoprazole and fipronil. The 19F NMR data produced for the 13C/12C analyses are also well suited for impurity profiling, providing an additional dimension for fingerprinting fluorinated organics. These findings suggest that position-specific isotope analysis can serve as part of a broader suite of tools for source characterization of organofluorine compounds and their breakdown derivatives, with potential applications in product validation, forensics, and linking these compounds to their breakdown products.

  PublisherDOI

• Exploring the origins of magnetization within the Chicxulub crater upper peak ring

  Meteoritics and Planetary Science · 2025-02-28 · 2 citations

  articleOpen accessSenior author

  Abstract Large terrestrial impacts may produce vast subsurface hydrothermal systems, capable of generating conditions favorable to the origin of life. Modeling suggests that these systems may persist for >1 million years for basin‐sized craters; however, direct experimental constraints on hydrothermal system duration are needed. Paleomagnetism may be used as a tool to study the nature and duration of the postimpact hydrothermal system generated within the upper peak ring of the 200 km diameter Chicxulub crater (Yucatán Peninsula, México). Previous work observed that upper peak ring suevite samples contained characteristic remanent magnetizations with negative and positive inclinations, with most samples having a magnetic inclination close to −44°, the expected paleoinclination at the crater at the time of the impact. This magnetic record was at the time interpreted as chemical remanent magnetization (CRM) acquired over a period of at least 150 thousand years, from the time of the impact in geomagnetic Chron C29r into Chron C29n. We conducted further paleomagnetic and rock magnetic studies of upper peak ring rocks and found that, while most samples likely contain CRM acquired during Chron C29r, the dispersion of magnetic inclinations within suevite subunits is more likely attributed to pre‐depositional remanence held within clasts than the recording of magnetic reversals. Therefore, the paleomagnetic record of the peak ring suevites is non‐ideal for inferring the duration of the Chicxulub postimpact hydrothermal system.

  PublisherOA PDFDOI

• Fingerprinting Organofluorine Molecules via Position-Specific Isotope Analysis

  Environmental Science & Technology · 2024-07-18 · 4 citations

  article1st authorCorresponding

  Organofluorine substances are found in a wide range of materials and solvents commonly used in industry and homes, as well as pharmaceuticals and pesticides. In the environment, organofluorine molecules are now recognized as an important class of anthropogenic pollutants. Fingerprinting organofluorine compounds via their carbon isotope ratios (13C/12C) is crucial for correlating molecules with their source. Here we apply a 19F nuclear magnetic resonance spectroscopy (NMR) technique to obtain the first position-specific carbon isotope ratios for a diverse set of organofluorine molecules. In contrast to traditional isotope ratio mass spectrometry, the 19F NMR method provides 13C/12C isotope ratios at each carbon position where a C–F bond is present, and does not require fragmentation or combustion to CO2, overcoming challenges posed by the robust C–F covalent bonds. The method was validated with 2,2,2-trifluoroethanol, and applied to analyze heptafluorobutanoic acid, 5-fluorouracil and fipronil. Results reveal distinct intramolecular carbon isotope distributions, enabling differentiation of chemically identical molecules. Notably, the NMR method accurately analyzes carbon isotopes within target molecules despite impurities. Potential applications include the detection of counterfeit products and drugs, and ultimately pollution tracking in the environment.

  PublisherDOI

• Position-specific carbon stable isotope analysis of glyphosate: isotope fingerprinting of molecules within a mixture

  Analytical and Bioanalytical Chemistry · 2024-05-14 · 4 citations

  articleSenior author
  PublisherDOI

• COLORADO PLATEAU CORING PROJECT PHASE 2 (CPCP-2): A CONTINUOUS RECORD OF TRIASSIC-JURASSIC CONTINENTAL ENVIRONMENTAL CHANGE

  Abstracts with programs - Geological Society of America · 2023-01-01

  article
  PublisherDOI

• A geochronologically-constrained stable isotope record of the Upper Triassic Sonsela Member (Chinle Formation) at Petrified Forest National Park (Arizona, USA): Testing for paleoenvironmental linkages with biotic change and the Manicouagan impact

  Palaeogeography Palaeoclimatology Palaeoecology · 2022-05-20 · 1 citations

  article1st authorCorresponding
  PublisherDOI

• Absolute Carbon Stable Isotope Ratio in the Vienna Peedee Belemnite Isotope Reference Determined by ¹H NMR Spectroscopy

  Analytical Chemistry · 2022 · 43 citations

  Senior authorCorresponding
  • Chemistry
  • Environmental chemistry
  • Chromatography

  C. Results provide a new and independent measure of the carbon isotope composition of VPDB, improving our understanding of this important isotope reference.

  PublisherOA PDFDOI

• Grouping behavior in a Triassic marine apex predator

  Current Biology · 2022-12-01 · 16 citations

  article
  PublisherDOI

• Novel Nuclear Magnetic Resonance Method for Position-Specific Carbon Isotope Analysis of Organic Molecules with Significant Impurities

  Analytical Chemistry · 2022 · 10 citations

  1st authorCorresponding
  • Chemistry
  • Nuclear magnetic resonance
  • Stereochemistry

  Cα isotope spikes in USGS74 and USGS75 were clearly detected, where they preserve carbon isotope ratios of -4.8 ± 0.9‰ and +11.5 ± 0.8‰, respectively. Carbon isotope abundance at the beta and gamma positions indicates that the USGS73 l-valine was obtained from a different source than USGS74 and -75. This analytical approach is a significant step forward in the field of position-specific isotope analysis at natural abundance via NMR because it enables the investigation of samples that contain impurities which are typically present in samples derived from natural sources.

  PublisherOA PDFDOI

Frequent coauthors

• et al.

  162 shared

• S. P. S. Gulick

  The University of Texas at Austin

  49 shared

• A. Wittmann

  Arizona State University

  49 shared

• D. A. Kring

  Purdue University West Lafayette

  46 shared

• Randall B. Irmis

  University of Utah

  44 shared

• R. Ocampo

  44 shared

• Dennis V. Kent

  Columbia University

  42 shared

• Christopher J. Lepre

  Bowling Green State University

  42 shared

Education

• Ph.D.

  University of Utah

  2018

• M.S.

  University of Munich

  2013

• B.S.

  University of Munich

  2010