Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-27T10:54:14.810Z Has data issue: false hasContentIssue false
  • English
  • Français

Ultra-Microscale (5–25 μg C) Analysis of Individual Lipids by 14C AMS: Assessment and Correction for Sample Processing Blanks

Published online by Cambridge University Press:  18 July 2016

Sunita R Shah  and
Ann Pearson
Sunita R Shah
Affiliation:
Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02140, USA
Ann Pearson*
Affiliation:
Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02140, USA
*
Corresponding author. Email: pearson@eps.harvard.edu.
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Measurements of the natural abundance of radiocarbon in biomarker molecules can be used to elucidate the biogeochemical roles of marine bacteria and archaea in the oceanic water column. However, the relatively low concentration of biomass, especially below the euphotic zone, inevitably results in small sample sizes for compound-specific analyses. In ultra-microscale Δ14C measurements, which we define as measurements on samples smaller than 25 μg C, the process of isolating pure compounds and preparing them for measurement adds significant background carbon. This additional blank carbon can contribute up to 40% of the total sample mass; therefore, it is necessary to quantify all components of the processing blank in order to make appropriate corrections. Complete propagation of error is critical in order to report the correct analytical uncertainty. The carbon blank is composed of at least 3 different sources: i) those that scale in proportion to the mass of the sample; ii) sources that contribute a constant mass of blank, e.g. closed-tube combustion; and iii) contaminants from vacuum lines and/or other aspects of sample handling that are difficult to quantify. We approached the problem of correcting for the total sample processing blank by deriving a 4-part isotopic mass balance based on separating the 3 exogenous components from the sample. Subsequently, we derived the appropriate equations for the full propagation of error associated with these corrections. Equations for these terms are presented. Full treatment of a set of raw data is demonstrated using compound-specific Δ14C data from the North Central Pacific water column.

Type
Articles
Information
Radiocarbon , Volume 49 , Issue 1 , 2007 , pp. 69 - 82
Copyright
Copyright © 2007 by the Arizona Board of Regents on behalf of the University of Arizona 

References

Dalsgaard, T, Canfield, DE, Petersen, J, Thamdrup, B, Acuña-González, J. 2003. N2 production by the anammox reaction in the anoxic water column of Golfo Dulce, Costa Rica. Nature 422(6932):606–8.CrossRefGoogle ScholarPubMed
Druffel, ERM, Williams, PM, Bauer, JE, Ertel, JR. 1992. Cycling of dissolved and particulate organic matter in the open ocean. Journal of Geophysical Research 97(C10):15,639–59.CrossRefGoogle Scholar
Eglinton, TI, Benitez-Nelson, BC, Pearson, A, McNichol, AP, Bauer, JE, Druffel, ERM. 1997. Variability in radiocarbon ages of individual organic compounds from marine sediments. Science 277(5327):796–99.CrossRefGoogle Scholar
Francis, CA, Roberts, KJ, Beman, JM, Santoro, AE, Oakley, BB. 2005. Ubiquity and diversity of ammonia-oxidizing archaea in water columns and sediments of the ocean. Proceedings of the National Academy of Science 102(41):14,683–8.CrossRefGoogle ScholarPubMed
Herndl, GJ, Reinthaler, T, Teira, E, van Aken, H, Veth, C, Pernthaler, A, Pernthaler, J. 2005. Contribution of Archaea to total prokaryotic production in the deep Atlantic Ocean. Applied and Environmental Microbiology 71(5):2303–9.CrossRefGoogle ScholarPubMed
Hemes, PJ, Benner, R. 2002. Transport and diagenesis of dissolved and particulate terrigenous organic matter in the North Pacific Ocean. Deep-Sea Research I 49:2119–32.Google Scholar
Hwang, JS, Druffel, ERM. 2003. Lipid-like material as the source of the uncharacterized organic carbon in the ocean? Science 299(5608):881–4.CrossRefGoogle ScholarPubMed
Ingalls, AE, Anderson, RF, Pearson, A. 2004. Radiocarbon dating of diatom-bound organic compounds. Marine Chemistry 92(1–4):91–105.CrossRefGoogle Scholar
Ingalls, AE, Shah, SR, Hansman, RL, Aluwihare, LI, Santos, GM, Druffel, ERM, Pearson, A. 2006. Quantifying archaeal community autotrophy in the mesopelagic ocean using natural radiocarbon. Proceedings of the National Academy of Science 103(17):6442–7.CrossRefGoogle ScholarPubMed
Kuypers, MMM, Sliekers, AO, Lavik, G, Schmid, M, Jørgensen, BB, Kuenen, JG, Damsté, JSS, Strous, M, Jetten, MSM. 2003. Anaerobic ammonium oxidation by anammox bacteria in the Black Sea. Nature 422(6932):608–11.CrossRefGoogle ScholarPubMed
Loh, AN, Bauer, JE, Druffel, ERM. 2004. Variable ageing and storage of dissolved organic components in the open ocean. Nature 430(7002):877–81.CrossRefGoogle ScholarPubMed
Ohkouchi, N, Eglinton, TI, Keigwin, LD, Hayes, JM. 2002. Spatial and temporal offsets between proxy records in a sediment drift. Science 298(5596):1224–7.CrossRefGoogle Scholar
Pearson, A, McNichol, AP, Schneider, RJ, von Reden, KF. 1998. Microscale AMS 14C measurement at NOSAMS. Radiocarbon 40(1):61–76.CrossRefGoogle Scholar
Pearson, A, McNichol, AP, Benitez-Nelson, BC, Hayes, JM, Eglinton, TI. 2001. Origins of lipid biomarkers in Santa Monica Basin surface sediment: a case study using compound-specific Δ14C analysis. Geochimica et Cosmochimica Acta 65(18):3123–37.CrossRefGoogle Scholar
Santos, GM, Southon, JR, Druffel, ERM, Rodriguez, KC, Griffin, S, Mazon, M. 2004. Magnesium perchlorate as an alternative water trap in AMS graphite sample preparation: a report on sample preparation at the KCCAMS Facility at the University of California, Irvine, Radiocarbon 46(1):165–73.CrossRefGoogle Scholar
Santos, GM, Southon, JR, Griffin, S, Beaupre, SR, Druffel, ERM. Forthcoming. Ultra small-mass AMS 14C sample preparation and analysis at the KCCAMS/UCI Facility. Nuclear Instruments and Methods in Physics Research B. doi: 10.1016/j.nimb.2007.01.172.CrossRefGoogle Scholar
Southon, JR, Santos, GM, Druffel-Rodriguez, K, Druffel, ERM, Trumbore, S, Xu, XM, Griffin, S, Ali, S, Mazon, M. 2004. The Keck Carbon Cycle AMS laboratory, University of California, Irvine: initial operation and a background surprise. Radiocarbon 46(1):41–9.CrossRefGoogle Scholar
von Reden, KF, Schneider, RJ, McNichol, AP, Pearson, A. 1998. 14C AMS measurements of <100 μg samples with a high-current system. Radiocarbon 40(1):247–53.Google Scholar
Wang, X-C, Druffel, ERM, Griffin, S, Lee, C, Kashgarian, M. 1998. Radiocarbon studies of organic compound classes in plankton and sediment of the northeastern Pacific Ocean—results from sediment trap experminents. Geochimica et Cosmochimica Acta 62(8):1365–78.CrossRefGoogle Scholar