title: The effect of aging on pyrene transformation in sediments.
abstract: The effect of aging on pyrene transformation and pyrene association with fractions of the sedimentary organic matrix (SdOM) was evaluated using [4,9-(13)C2]pyrene. Sediments were collected from a site of previous petroleum hydrocarbon contamination (New Orleans, LA, USA). Aged sediments were autoclaved for 1 h, amended with pyrene, and then stored in the dark in a 0.05% NaN3 solution for 120 d. Both aged and nonaged sediments were incubated in aerated microcosms for 120 d. Microcosms were acidified to collect evolved carbon dioxide (CO2); sediments were fractionated and lipid extracted to quantify pyrene in SdOM fractions. Cross-polarization magic angle spinning 13C-nuclear magnetic resonance (CPMAS 13C-NMR) spectra indicated that synthetic aging techniques did alter SdOM structure to some degree, but these changes did not affect SdOM affinity for pyrene. Aging delayed pyrene mineralization and increased pyrene concentrations extracted from bulk sediment and humic fractions. Aging also reduced the toxicity of sediment humin. Pyrene-4,5-dione and pyrene cis-4,5-dihydrodiol were identified in extracts of aged sediments by 13C-NMR and gas chromatography mass spectrometry, respectively.
authors.affiliation: Environmental Technology Program, Box 8002, 2022B Biltmore Hall, North Carolina State University, Raleigh, North Carolina 27695, USA. elizabeth_nichols@ncsu.edu
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Guthrie-Nichols
authors.forename: Adam
authors.initials: A
authors.lastname: Grasham
authors.forename: Chikoma
authors.initials: C
authors.lastname: Kazunga
authors.forename: Ramiah
authors.initials: R
authors.lastname: Sangaiah
authors.forename: Avram
authors.initials: A
authors.lastname: Gold
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Bortiatynski
authors.forename: Myrna
authors.initials: M
authors.lastname: Salloum
authors.forename: Patrick
authors.initials: P
authors.lastname: Hatcher
mesh_terms: D001711:Biotransformation; D002245:Carbon Dioxide / Q000032:analysis; D002247:Carbon Isotopes / Q000032:analysis; D005456:Fluorescent Dyes / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D019015:Geologic Sediments / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D011721:Pyrenes / Q000378:metabolism*; D012989:Soil Pollutants / Q000493:pharmacokinetics*
chemical_list: D002247:Carbon Isotopes; D005456:Fluorescent Dyes; D011721:Pyrenes; D012989:Soil Pollutants; D002245:Carbon Dioxide; C030984:pyrene