In this study, the use of a {sup}(13)C-labeled pollutant probe, {sup}(13)Cpyrene, and the application of flash pyrolysis-GCMS and CPMAS{sup}13C NMR provided analytical capabilities to study pyrene interactions with soluble and insolublecompartments of sedimentary organic matter (S{sub}DOM) during whole sediments incubations in aerated microcosms. Surface sediments were collected from a site of previous hydrocarbon contamination in New Orleans, LA. Over a period of 60 days, humic acidand humin fractions of S{sub}DOM accumulated increasing amounts of pyrene that were resistant to exhaustive extraction with organic solvents. The sequestered pyrene was evident in CPMAS{sup}(13)C NMR spectra of humin fractions. The amount of sequesteredpyrene in humic materials was quantified by flash pyrolysis-GC-MS, a technique that destroys the three-dimensional structure of macromolecular S{sub}DOM. Noncovalent binding of pyrene to humic materials in S{sub}DOM was greater in sediments incubated with biological activity than biocide-treated sediments. The combined analytical approaches demonstrate that the sequestered pyrene, or bound residue, is noncovalently associated with S{sub}DOM and has not undergone structural alteration. Implications of these data are discussed in reference to S{sub}DOM diagenesis and long-term availability of bound pollutant residues in sediments.
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