Molecular, Radioactive and Stable Carbon Isotope Characterization of Estuarine Particulate Organic Matter

Abstract

ABSTRACT. Organic matter in sediments and suspended matter is a complex mixture of constituents with different histories, sources and stabilities. To study these components in a suspended matter sample from the Ems-Dollard Estuary, we used combined molecular analysis with pyrolysis/gas chromatography/mass spectrometry and stable and radioactive carbon isotope analyses of the bulk and separated chemical fractions. Carbohydrates and proteins, ca. 50% of the total organic carbon (TOC), are much younger than the bulk sample and have a somewhat higher 613C value. Lipids and the final residue are considerably older and have lower 613C values. The final residue, ca. 17% of the total carbon, consists mainly of aliphatic macromolecules that could be derived from algae or terrestrial plants. The 613C value points to a marine origin.

Investigation of the Role of Structural Domains Identified in Sedimentary Organic Matter in the Sorption of Hydrophobic Organic Compounds

“…For the pairs of samples taken from each estuary, the upperestuary samples had consistently more negative δ 13 C values. These are consistent with values of approximately -21 and -27% that can be expected for marine-and terrestrial-derived organic matter, respectively (46), and are similar to values obtained for Dutch estuarine sediments by Megens et al (47). The δ 13 C value for the spiked samples are well outside natural values due to the contribution of 13 C in the added phenanthrene.…”

Carbon isotope variability in monosaccharides and lipids of aquatic algae and terrestrial plants

“…This will make it more difficult to distinguish between the different sources of the organic matter based solely on δ 13 C DOM and δ 13 C POC signals, and alternative methods need to be used, e.g. 14 C analysis (Megens et al 1998).…”

Compound‐specific radiocarbon dating of the varved Holocene sedimentary record of Saanich Inlet, Canada

“…CSRA may be of particular utility for samples where other dating methods are impractical or to supplement dates on “traditional” materials (e.g., organic macrofossils or carbonate), in order to increase precision or resolution [ Eglinton et al , 1997]. To date, CSRA has almost exclusively been used to address carbon source related questions, by investigating the spread in radiocarbon age between different sedimentary components [ Pearson et al , 2001; Petsch et al , 2001; Ohkouchi et al , 2002] in a manner that is comparable to radiocarbon analysis of fractions from the total organic carbon [e.g., Druffel et al , 1996; Megens et al , 1998; Wang et al , 1998; Trumbore , 2000; Raymond and Bauer , 2001b]. Recently, Ohkouchi et al [2003] showed that CSRA might be used for improving the sediment chronology of Antarctic margin sediments.…”