Date of Award
A comprehensive understanding of the reactivity associated with organic carbon is critical for recognizing the behavior of newly formed compounds in aquatic environments. In an effort to study the reactivity of complex mixtures, understanding the different processes affiliated with them are key. Understanding the reactivity associated with organic carbon can help to improve chromatographic separation. Using a combination of light and heavy crude oil, a separation procedure was developed to obtain a complete representation of the aromatic subfraction of the crude oil sample. The crude oils were separated into four distinct fractions based on the number of condensed aromatic rings present (saturates, 1 -2 ring, 3 – 4 ring and 5+ ring). Each ring fraction was placed in thin films (30 μm) over nanopure water and photodegraded for 12 hours. The dissolved organic matter (DOM) generated from each fraction was subjected to a photodegradation time series from 0 – 96 h in 24 h increments. Each DOM degradation time series was measured using excitation emission matrix spectroscopy (EEMs) and statistical analysis were applied using parallel factor analysis (PARAFAC), to identify the underlying fluorophores present in the sample set. Small scale preparations were performed to ensure the integrity of the separation would be maintained during a bulk scale up. It was determined that a 2 % loading of sample would yield desired fractions with minimal overlap. Dissolved organic carbon and absorbance measurements collectively decreased with increasing exposure time.
Long, Jonathan A. Jr, "Isolation and Determination of the Composition and Structural Components that Comprise Dissolved Organic Matter Using Normal Phase Liquid Chromatography" (2021). University of New Orleans Theses and Dissertations. 2848.