Summer 2018 – GoMRI Researcher Interview with Dr. Ryan Rodgers

(From Summer 2018 Newsletter) Dr. Ryan Rodgers from the National High Magnetic Field Laboratory at Florida State University answered a few questions about his RFP-V project, The State-of-the-Art Unraveling of the Biotic and Abiotic Chemical Evolution of Macondo Oil: 2010-2018, his RFP-VI project, Molecular Understanding of Emulsion Formation in Environmentally Photo-Oxidized Crude Oils: In Situ Generation of Interfacially Active Species and Their Impact on Emulsification, and his work as a research scientist with the Deepsea to Coast Connectivity in the Eastern Gulf of Mexico (Deep-C) consortium.

For more information on Dr. Rodgers, his background, and his research, please visit the National High Magnetic Field Laboratory’s website and the excellent article they published on him in recognition of his receiving Florida State University’s Distinguished Scholar Award.

1. Thank you so much for talking with us! What are the goals of your RFP-V project, “The State-of-the-Art Unraveling of the Biotic and Abiotic Chemical Evolution of Macondo Oil: 2010-2018?”

The goals of this project are to understand the molecular-level weathering of the Macondo oil over a ten-year time period, and based on these results, determine the dominant mechanism(s) that modify oil’s initial composition (new components are termed “transformation products”). Once identified, the mechanism(s) are mimicked in the lab, and the molecular-level data from these samples are compared to those from field samples. Success in these efforts allow lab-based methods to be used to generate field relevant transformation products that can be both modeled for toxicity and directly tested for toxicity. These species (compounds) are the fraction of transformation products that become water soluble, and thus bioavailable.

2. What are the goals of your RFP-VI project, “Molecular Understanding of Emulsion Formation in Environmentally Photo-Oxidized Crude Oils: In Situ Generation of Interfacially Active Species and Their Impact on Emulsification?”

The research above (from the RFP-V project) identified photo-oxidation as the main source of transformation products. More importantly, it identified a continuum of oxidized transformation products that spanned both oil soluble and water soluble species. The work above focused on the water soluble species. As we had the molecular- level data for various solar exposure times, as well as for both the oil/water soluble species, a very distinct progression (from oil soluble to water soluble species) was exposed. Fortuitously, earlier research at the National High Magnetic Field Lab led to the development of a method that could easily and effectively isolate interfacially active species (species that cause emulsions) from oil samples. When we performed the isolation on the photo- irradiated crude oils, the oil soluble transformation products split into two fractions: those species that were oil soluble but not interfacially active, and those that were oil soluble and interfacially active. This answered numerous questions. Photo-oxidation generates surfactants (interfacially active species), and these species cause floating oil to swell with water. This in turn causes the thick mousse-like material observed after the spill. It also explains why dispersants are ineffective on weathered oil. The oil composition is altered as it weathers, including the generation of surfactants, and this reduces the effectiveness of dispersants. However, many questions remain. This grant will specifically address the generation of surfactants through the photo-oxidation of crude oil and how these species cause emulsions.

3. You also worked with the Deepsea to Coast Connectivity in the Eastern Gulf of Mexico (Deep-C) consortium. Could you tell us about your research with Deep-C?

Our involvement in Deep-C led to the initial characterization of the oxidized transformation products and we started to address the oxygen-containing functionalities in field samples. We identified ketones, carboxylic acids, and hydroxyl-containing species. This work led to the RFP-V project “The State-of-the-Art Unraveling of the Biotic and Abiotic Chemical Evolution of Macondo Oil: 2010-2018.”

4. What are some of the most significant or exciting findings so far from your GoMRI- funded research?

The characterization of the transformation products. Tens-of-thousands of these species have been identified at the level of molecular formula assignment. Photo-oxidation is the major source of these species. Transformation products are oil and water soluble. The oil soluble species include photo-generated surfactants. The water soluble species are initially more toxic than the original oil, but that toxicity drops over time.

5. Can you share a bit about you and your colleagues’ involvement in GoMRI’s Synthesis and Legacy effort?

Woods Hole Oceanographic Institution (WHOI) and the National High Magnetic Field Lab will participate in two of the synthesis efforts: Analytical Methods and Photochemistry. GoMRI-funded research exposed the importance and complexity of transformation products. It also established methods for their detailed characterization. Although much research remains, the path has been established. It will be exciting to see where it leads, but it needs to be put in context with all the other previous knowledge and emerging research. That is what we hope to accomplish in the coming months.

6. Please tell us about some of your outreach activities.

Chris Reddy, Chris Aeppli, and myself have given numerous talks to the general public, students, and scientific community. We also led a “student scientist” program at Florida State University School for high school students. We took 25 students on a field trip  to collect tar balls from a beach near Fort Morgan, Alabama. The 25 students included five students from the AV  club who filmed the trip and talked to  the students during and after the field trip. They are creating a mini-documentary of the trip. Dr. Collin Ward from WHOI and I attended the trip. (The documentary will be publicly available, and GoMRI will be sure to share it once it’s completed. Stay tuned!)

7. If funding were not an issue, what would you add to your projects?

This could take many additional pages, but the main focus would be to expand to other types of crude oils/ refined products that might be spilled in the future and to understand the impact of the transformation products from these materials.

[Back to the Summer 2018 Newsletter]