Increase in acetate concentrations during sediment sample onboard storage; a caution for pore-water geochemical analyses

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doi: 10.2343/geochemj.2.0272
Author(s): Ijiri, Akira; Ohtomo, Yoko; Morono, Yuki; Ikehara, Minoru; Inagaki, Fumio
Author Affiliation(s): Primary:
Japan Agency for Marine-Earth Science and Technology, Kochi Institute of Core Sample Research, Nankoku, Japan
Kochi University, Japan
Volume Title: Geochemical Journal
Source: Geochemical Journal, 47(5), p.567-571. Publisher: Geochemical Society of Japan, Nagoya, Japan. ISSN: 0016-7002 CODEN: GEJOBE
Note: In English. 10 refs.; illus.
Summary: Microbial activity in marine sediment plays an important biogeochemical role in cycling of carbon and other elements. Acetate is a key intermediate of various microbial metabolic pathways. In this study, we measured concentrations and stable carbon isotopic compositions (δ13C) of acetate in pore water of two core samples stored at near in-situ temperatures (4°C) within 3 hours and at room temperatures (25°C) for 19 hours after sample recovery. Acetate concentrations at 4°C were less than 3 µM throughout the sediment column, whereas they increased up to 13 µM in the samples stored at 25°C and corresponding δ13C values of acetate were enriched up to 8.7 ppm relative to those of total organic carbon. Our results indicate that acetate-mediated microbial activity is rapidly changed with temperature increase and possible air contamination, and also suggest that sample processing at near in-situ temperatures in the short-term is required for accurate pore-water geochemical analysis.
Year of Publication: 2013
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 02 Geochemistry; Acetates; Biochemistry; C-13/C-12; Carbon; Chemical analysis; Concentration; Esters; Geochemistry; IODP Site C0020; In situ; Integrated Ocean Drilling Program; Isotope ratios; Isotopes; Marine sediments; Metabolism; Methods; Microorganisms; North Pacific; Organic compounds; Pacific Ocean; Pore water; Sample preparation; Sampling; Sediments; Stable isotopes; Sulfate ion; Temperature; Total organic carbon
Coordinates: N411100 N411100 E1421200 E1421200
Record ID: 2014014390
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