Chemical Characteristics of Sediment Associated Organic Matter Untitled
EMSL Project ID
48046
Abstract
A significant body of evidence (Conant et al, 2011; Schmidt et al., 2011; Kleber, 2010) concludes that association of organic matter (OM) with minerals has a significant impact on the rate of carbon cycling in soil and the persistence of a fraction of organic matter in deep soils (>1 m). However, the mechanisms by which OM-mineral interactions control carbon cycling are not well understood. The proposed work will used FT-ICR-MS to understand the chemical differences between distinct fractions of sediment associated organic matter. The FT-ICR-MS capabilities of EMSL will allow for a degree of structural information on the organic matter unavailable through any other analytical technique. The proposed work contributes simultaneously to three of EMSL’s core mission areas of global carbon cycling, biogeochemistry, and subsurface science. We will evaluate the utility of four selective chemical extraction techniques using conventional methods at LBNL (total organic carbon and excitation-emission spectroscopy) to extract organic matter associated to the solid phase by different mechanisms. Following this evaluation, samples obtained from three extractions will be analyzed by FT-ICR-MS to compare their chemical characteristics of organic matter. We take as our preliminary task distinguishing the quantity and chemical structure of organic matter associated with the sediment by the two mechanisms: 1) complexation by Fe and Al, 2) co-precipitation with Fe (hydr)oxides. The extractions are designed to release organic matter held by one of these two mechanisms.
Project Details
Project type
Limited Scope
Start Date
2013-04-30
End Date
2013-06-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
Fox PM, PS Nico, MM Tfaily, and JA Davis. 2017. "Characterization of Natural Organic Matter in Low-Carbon Environments: Extraction and Analytical Approaches." Environmental Science & Technology 114(12-22):, doi:10.1016/j.orggeochem.2017.08.009