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Evidence for bias in measured [delta]15N values of terrestrial and aquatic organic materials due to pre-analysis acid treatment methods

By Chris R. Brodie, Tim H.E. Heaton, Melanie J. Leng, Christopher P. Kendrick, James S.L. Casford and Jeremy M. Lloyd

Abstract

We investigate the effect of acid treatment methods on δ15N values from a range of environmental organic materials in the context of the increased application of ‘dual-mode’ isotope analysis (the simultaneous measurement of δ13C and δ15N from the same acid-treated sample). Three common methods are compared; (i) untreated samples; (ii) acidification followed by sequential water rinse (rinse method); and (iii) acidification in silver capsules (capsule method). The influence of capsule type (silver and tin) on δ15N is also independently assessed (as the capsule and rinse methods combust samples in different capsules; silver and tin, respectively). We find significant differences in δ15N values between methods and the precision of any one method varies significantly between sample materials and above the instrument precision (>0.3‰). The δ15N values of untreated samples did not produce the most consistent data on all sample materials. In addition, the capsule type appears to influence the measured δ15N value of some materials, particularly those combusted only in silver capsules. We also compare the new δ15N data with previously published δ13C data on the same materials. The response of δ13C and δ15N within and between methods and sample materials to acidification appears to be relatively disproportionate, which can influence the environmental interpretation of the measured data. In addition, statistical methods used to estimate inorganic nitrogen are shown to be seriously flawed

Publisher: Wiley
Year: 2011
DOI identifier: 10.1002/rcm.4970
OAI identifier: oai:nora.nerc.ac.uk:14254

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  1. (1997). 13C and 15N abundances in the sediment core (VER 92/1-St-10-GC2) from northern Lake Baikal. Isotopes in Environ. Health Stud.
  2. (2001). Acid fumigation of soils to remove carbonates prior to total organic carbon or carbon-13 analysis.
  3. (2008). Acid washing effect on elemental and isotopic composition of whole beach anthropods: Implications for food web studies using stable isotopes. Acta Oecolog.
  4. (2007). al Determination of Total Organic Carbon Content and
  5. (1980). Analysis of organic carbon in marine sediments.
  6. (1998). Analysis of total and organic carbon and total nitrogen in settling oceanic particles and a marine sediment: an interlaboratory
  7. (2003). Applications of organic geochemistry to paleolimnological reconstructions: A summary of examples from the Laurentian Great Lakes.
  8. (1977). C/N ratio in Pacific deep-sea sediments: effect of inorganic ammonium and organic nitrogen compounds sorbed by clays.
  9. (2008). C/N ratios in a sediment core from Nakaumi Lagoon, southwest Japan. Usefulness as an organic source indicator.
  10. (2006). Carbon and Nitrogen geochemistry of wedge sediments at ODP site 1040: Evidence for sediment sources, diagenetic history and fluid mobility. In:
  11. (2005). Carbon and nitrogen isotope composition of bulk soils, particle-size fractions and organic material after treatment with hydrofluoric acid.
  12. (2000). Carbonate removal by acidification causes loss of nitrogenous compounds in continental margin sediments.
  13. (2008). Catastrophic hurricane history revealed by organic geochemical proxies in coastal lake sediments: a case study of Lake Shelby,
  14. (1999). Changes in carbon and nitrogen cycling during tree-line retreat recorded in the isotopic content of lacustrine organic matter, western Taimyr Peninsula, Russia. The Holocene.
  15. (1995). Climate-related variations in denitrification in the Arabian Sea from sediment 14N/15N ratios.
  16. (1999). Compound specific δ15N‰ values: amino acids in grasslands and arable soils.
  17. (2008). Consistent relationship between global climate and surface nitrate utilization in the western subarctic Pacific throughout the last 500ka. Paleoceanography.
  18. Constraints on oceanic N balance/imbalance from sedimentary N-15 records.
  19. (1999). Differential fractionation of 13C and 15N among fish tissues: implications for the study of trophic interactions.
  20. (2006). Distribution and sources of organic carbon, nitrogen and their isotopes in sediments of the subtropical Pearl river estuary and adjacent shelf,
  21. (2001). Early diagenesis of organic matter from sediments of the easter subtropical Atlantic: Evidence from stable nitrogen and carbon isotopes.
  22. (1995). Effects of acid washing on stable isotope ratios of C and N in penaeid shrimp and seagrass: Implications for food-web studies using multiple stable isotopes.
  23. (2008). Effects of acidification in multiple stable isotope analyses.
  24. (2008). Effects of acidification on carbon and nitrogen stable isotopes of benthic macrofauna from a tropical coral reef. Rapid Commun. Mass Spectrom.
  25. (2000). Effects of decarbonation treatments on δ13C values in marine sediments.
  26. (2002). Effects of sample preparation on the measurement of organic carbon, hydrogen, nitrogen, sulfur, and oxygen concentrations in marine sediments.
  27. (2008). How does acid treatment to remove carbonates affect the isotopic and elemental composition of soils and sediments?
  28. (1016). Influence of preparation methods on C and N concentrations and δ13C composition of terrestrial and aquatic organic materials Chem.
  29. (1987). Natural variations in 15N in the marine environment.
  30. (2001). Nitrogen and carbon isotopic composition of marine and terrestrial organic matter in Arctic Ocean sediments: implications for nutrient utilisation and organic matter composition. Deep-Sea research I.
  31. (1985). Organic and inorganic nitrogen in sediments from Leg 80, Deep Sea drilling Programme, In: Graciansky,
  32. (1997). Organic geochemical proxies of palaeoceanographic, palaeolimnologic, and palaeoclimatic processes.
  33. (2004). Palaeoclimate interpretation of stable isotope data from lake sediments. Quaternary Sci. Rev.
  34. (2007). Principles of Isotope Geochemistry
  35. (2010). Regulation of the nitrogen biogeochemistry of mountain lakes by subsidies of terrestrial dissolved organic matter and the implications for climate studies.
  36. (2007). Sedimentary evidence for recent eutrophication in the northern basin of Lake Taihu, China: human impacts on a large shallow
  37. (1998). Soil carbonate decomposition by acid has little effect on 13C of soil organic matter.
  38. (2010). Stable isotopes of bulk organic matter to trace carbon and nitrogen dynamics in an estuarine ecosystem in Babitonga Bay
  39. (2005). The Effect of acidification on the determination of organic carbon, total nitrogen and their stable isotopic composition in algae and marine sediment. Rapid Commun. Mass Spectrom.
  40. (2007). The effects of acidification on the stable isotope signatures of marine algae and molluscs.
  41. (2005). The nitrogen cycle of the Baltic Sea from an isotopic perspective.
  42. (2010). δ15N values in Lake Erie sediments as indicators of nitrogen biogeochemical dynamics during cultural eutrophication.

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