title: Sediment Core Sectioning and Extraction of Pore Waters under Anoxic Conditions.
abstract: We demonstrate a method for sectioning sediment cores and extracting pore waters while maintaining oxygen-free conditions. A simple, inexpensive system is built and can be transported to a temporary work space close to field sampling site(s) to facilitate rapid analysis. Cores are extruded into a portable glove bag, where they are sectioned and each 1-3 cm thick section (depending on core diameter) is sealed into 50 ml centrifuge tubes. Pore waters are separated with centrifugation outside of the glove bag and then returned to the glove bag for separation from the sediment. These extracted pore water samples can be analyzed immediately. Immediate analyses of redox sensitive species, such as sulfide, iron speciation, and arsenic speciation indicate that oxidation of pore waters is minimal; some samples show approximately 100% of the reduced species, e.g. 100% Fe(II) with no detectable Fe(III). Both sediment and pore water samples can be preserved to maintain chemical species for further analysis upon return to the laboratory.
authors.affiliation: Department of Chemistry, Vassar College; alspodek@vassar.edu.
authors.forename: Alison R
authors.initials: AR
authors.lastname: Keimowitz
authors.affiliation: Division of Geochemistry, Lamont-Doherty Earth Observatory.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Department of Geosciences, Auburn University.
authors.forename: Ming-Kuo
authors.initials: MK
authors.lastname: Lee
authors.affiliation: Department of Geosciences, Auburn University.
authors.forename: Michael
authors.initials: M
authors.lastname: Natter
authors.affiliation: Department of Geosciences, Auburn University.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Keevan
mesh_terms: D005290:Ferric Compounds; D019015:Geologic Sediments / Q000032:analysis*; D055593:Geological Phenomena; D060587:Groundwater / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D005290:Ferric Compounds; D014874:Water Pollutants, Chemical