Rapid analysis of 13C in plant-wax n-alkanes for reconstruction of terrestrial vegetation signals from aquatic sediments

View/ Open
Date
2004-10-15Author
McDuffee, Kelsey E.
Concept link
Eglinton, Timothy I.
Concept link
Sessions, Alex L.
Concept link
Sylva, Sean P.
Concept link
Wagner, Thomas
Concept link
Hayes, John M.
Concept link
Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/457As published
https://doi.org/10.1029/2004GC000772DOI
10.1029/2004GC000772Abstract
Long-chain, odd-carbon-numbered C25 to C35 n-alkanes are characteristic components of epicuticular waxes produced by terrestrial higher plants. They are delivered to aquatic systems via eolian and fluvial transport and are preserved in underlying sediments. The isotopic compositions of these products can serve as records of past vegetation. We have developed a rapid method for stable carbon isotopic analyses of total plant-wax n-alkanes using a novel, moving-wire system coupled to an isotope-ratio mass spectrometer (MW-irMS). The n-alkane fractions are prepared from sediment samples by (1) saponification and extraction with organic solvents, (2) chromatographic separation using silica gel, (3) isolation of straight-chain carbon skeletons using a zeolite molecular sieve, and (4) oxidation and removal of unsaturated hydrocarbons with RuO4. Short-chain n-alkanes of nonvascular plant origin (<C25) are removed by evaporation on the moving wire. Test samples processed using this procedure yielded n-alkane fractions essentially free of interfering components. The δ13C values obtained by MW-irMS did not differ significantly from weighted averages of individual n-alkane δ13C values obtained by irmGC-MS. Isotopic variations in compound-class n-alkane fractions from a latitudinal transect of core-top sediments from the Southwest African margin (3°N–28°S) were congruent with those measured by compound-specific isotopic analyses of plant-wax n-alkanes. The amplitude of the variations was smaller, indicating contributions from non-plant-wax hydrocarbons, but the measurements revealed variations in carbon isotopic composition that are consistent with vegetation zones on the adjacent continent.
Description
Author Posting. © American Geophysical Union, 2004. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 5 (2004): Q10004, doi:10.1029/2004GC000772.
Suggested Citation
Geochemistry Geophysics Geosystems 5 (2004): Q10004Related items
Showing items related by title, author, creator and subject.
-
Influence of hydraulic connectivity on carbon burial efficiency in Mackenzie Delta lake sediments
Lattaud, Julie; Bröder, Lisa; Haghipour, Negar; Rickli, Joerg; Giosan, Liviu; Eglinton, Timothy I. (American Geophysical Union, 2021-02-02)The Arctic is undergoing accelerated changes in response to ongoing modifications to the climate system, and there is a need for local to regional scale records of past climate variability in order to put these changes ... -
Direct application of compound-specific radiocarbon analysis of leaf waxes to establish lacustrine sediment chronology
Uchikawa, Joji; Popp, Brian N.; Schoonmaker, Jane E.; Xu, Li (2006-12-18)This study demonstrates use of compound-specific radiocarbon analysis (CSRA) for dating Holocene lacustrine sediments from carbonate-hosted Ordy Pond, Oahu, Hawaii. Long-chain odd-numbered normal alkanes (n-alkanes), ... -
Hydrocarbon compounds identified and measured in sediments and porewaters using gas chromatography from R/V JOIDES Resolution IODP-385 cruise in the Guaymas Basin between September and November, 2019.
Edgcomb, Virginia P.; Teske, Andreas (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-08-12)Hydrocarbon compounds identified and measured in sediments and porewaters using gas chromatography from R/V JOIDES Resolution IODP-385 cruise in the Guaymas Basin between September and November, 2019 For a complete list ...