CAREER: Molecular-Level Behavior of Chromophores in Dissolved Organic Matter

With support from the Environmental Chemical Sciences Program of the Chemistry Division, Professor Garrett McKay of Texas A&M University will study the chemical structure of light-absorbing compounds in dissolved organic matter. Dissolved organic matter is one of the most abundant carbon sources on earth, and interaction with sunlight plays an important role in cycling this carbon in the environment.

Using advanced analytical tools and spectroscopy, the project will determine the structural components of light-absorbing groups in dissolved organic matter and the extent to which these groups interact with one another. Understanding how these light-absorbing groups interact will improve the ability to predict the fate and reactivity of dissolved organic matter in the environment.

In addition to training of undergraduate and graduate students, an educational outreach program, involving Lufkin High School’s (Lufkin, TX) Aquatic Science course, will give students who are members of underrepresented groups an opportunity to study dissolved organic matter chromophores in a local water body using state-of-the art techniques.

The structure of chromophores in dissolved organic matter governs the mechanisms and rates of key processes in aquatic systems, such as elemental cycles, attenuation of contaminants, and productivity of the Earth’s oceans. However, knowledge of the processes that shape DOM’s optical and photochemical properties remains elusive. This research will combine mass spectrometric, electrochemical, and separation techniques with multiple spectroscopies to unravel the prevalence and composition of donor-acceptor interactions between dissolved organic matter chromophores.

Studies conducted with carefully chosen model compounds will also be used to evaluate the structural drivers of these interactions.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.