Probing the Microheterogeneous Distribution of Photochemically Produced Hydroxyl Radicals in Dissolved Organic Matter.

ABSTRACT: Dissolved organic matter (DOM) is a major photosensitizer in sunlit surface waters that generates hydroxyl radicals (^•OH). While ^•OH is believed to form within hydrophobic DOM microdomains, its spatial distribution and phase-specific reactivity remain poorly characterized among DOM from diverse environments. In this study, we employed testosterone as a probe to quantify DOM-phase ^•OH concentration ([^•OH]_DOM) via hydrophobic partitioning. Across eight DOM isolates, [^•OH]_DOM was found to be 20-150 times higher than aqueous phase concentration ([^•OH]_aq). To explore the underlying drivers of this microheterogeneity, we evaluated [^•OH]_DOM/[^•OH]_aq in rela

SUBMITTER: Cheng K 

PROVIDER: S-EPMC12810377 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature