Determining Olefinic and Phenolic Fractions in Dissolved Organic Matter by Ozonation with Stable Oxygen Isotope Analysis of H 2 O 2
Year: 2026
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Reactivity-related characterization of dissolved organic matter (DOM) is crucial for mitigating undesirable byproduct formation during ozonation. However, the characterization of DOM remains challenging due to its molecular complexity, especially in distinguishing olefin- and phenol-type moieties, primary O 3 reactive sites responsible for generating carbonyl-containing byproducts. Here, we present a novel approach based on stable oxygen isotope analysis of H 2 O 2, a common byproduct of ozone reactions, to differentiate between these two moieties. The natural abundance oxygen isotopic signatures of residual H 2 O 2 (δ 18 O H 2 O 2 ) after ozonation with 13 model compounds (6 olefins and 7 phenols) at pH 3 and 7, and their pH-dependency, Δ 18 O H 2 O 2 (δ 18 O H 2 O 2 (pH 7) – δ 18 O H 2 O 2 (pH 3)), enabled the distinction of olefins and phenols. Olefins exhibited near-zero or positive Δ 18 O H 2 O 2 (0.4–9.0‰), whereas phenols showed negative Δ 18 O H 2 O 2 (−14.2 – −1.6‰). These contrasting trends allowed derivation of an empirical correlation linking Δ 18 O H 2 O 2 to olefinic-phenolic fractions in mixtures, resulting in estimation of molar fractions of the two moieties in DOM isolates. This stable-isotope based approach offers unique mechanistic insights into H 2 O 2 formation mechanisms for widespread applications in H 2 O 2 -generating reactions, as well as for synergistic use with existing DOM characterization techniques.
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Award: G1002077926
OpenAlex ID: W7155108031