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Naturwissenschaften

, Volume 93, Issue 9, pp 447–450 | Cite as

Characterisation of black carbon-rich samples by 13C solid-state nuclear magnetic resonance

  • Etelvino H. NovotnyEmail author
  • Michael H. B. Hayes
  • Eduardo R. deAzevedo
  • Tito J. Bonagamba
Short Communication

Abstract

There are difficulties in quantifying and characterising the organic matter (OM) in soils that contain significant amounts of partially oxidised char or charcoal materials. The anthropogenic black carbon (BC), such as that found in the Terra Preta de Índio soils of the Amazon region, is a good example of the OM that is difficult to analyse in such soils. 13C direct polarisation/magic angle spinning (DP/MAS) at high MAS frequency, 1H-13C cross polarisation (CP)/MAS with total suppression of spinning sidebands (TOSS), and chemical shift anisotropy (CSA) filter nuclear magnetic resonance techniques have been applied successfully for quantifying the different components of OM. However, because pyrogenic materials present strong local magnetic susceptibility heterogeneities, the use of CSA-filter and TOSS make the pulse sequences very sensitive to imperfections in the π pulses. In this study, the DP/MAS pulse sequence was replaced by a CP with a radio frequency ramp—variable amplitude CP (VACP)—VACP/MAS pulse sequence, and composite π pulses were used in the CSA-filter and TOSS pulse sequences. In that way, the component functionalities in a humic acid from a BC soil were successfully determined. The spectrometer time needed was greatly decreased by employing this VACP/MAS technique. This development provides an accurate method for characterising BC-rich samples from different origins.

Keywords

Humic Acid Black Carbon Magic Angle Spin Chemical Shift Anisotropy International Humic Substance Society 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgements

The authors acknowledge support from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)—Brazil, Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)—Brazil, Empresa Brasileira de Pesquisa Agropecuária (Embrapa)—Brazil, and Science Foundation Ireland, and Dr. Vinicius M. Benites (Embrapa Solos) and Dr. Tony J.F. Cunha (Embrapa Semi-Árido) for providing HA samples. The experiments comply with the current Brazilian laws.

References

  1. Benites VM, Mendonça ES, Schaefer CEGR, Novotny EH, Reis EL, Ker JC (2005) Properties of black soil humic acids from high altitude rocky complexes in Brazil. Geoderma 127:104–113CrossRefGoogle Scholar
  2. Bennett AE, Rienstra CM, Auger M, Lakshmi KV, Griffin RG (1995) Heteronuclear decoupling in rotating solids. J Chem Phys 103:6951–6958CrossRefGoogle Scholar
  3. Cook RL (2004) Coupling NMR to NOM. Anal Bioanal Chem 378:1484–1503PubMedCrossRefGoogle Scholar
  4. Fitzpatrick SW (1990) Manufacture of furfural and levulinic acid by acid degradation of lignocellulosic. World patent 8910362 to Biofine IncorporatedGoogle Scholar
  5. Freitas JCC, Bonagamba TJ, Emmerich FG (1999) 13C high-resolution solid-state NMR study of peat carbonization. Energy Fuels 13:53–59CrossRefGoogle Scholar
  6. Glaser B, Haumaier L, Guggenberger G, Zech W (2001) The ‘Terra Preta’ phenomenon: a model for sustainable agriculture in the humid tropics. Naturwissenschaften 88:37–41PubMedCrossRefGoogle Scholar
  7. González-Pérez JA, González-Vila FJ, Almendros G, Knicker H (2004) The effect of fire on soil organic matter—a review. Environ Int 30:855–870PubMedCrossRefGoogle Scholar
  8. Knicker H, Totsche KU, Almendros G, González-Vila FJ (2005) Condensation degree of burnt peat and plant residues and the reliability of solid-state VACP MAS 13C NMR spectra obtained from pyrogenic humic material. Org Geochem 36:1359–1377CrossRefGoogle Scholar
  9. Kramer RW, Kujawinski EB, Hatcher PG (2004) Identification of black carbon derived structures in a volcanic ash soil humic acid by Fourier transform ion cyclotron resonance mass spectrometry. Environ Sci Tech 38:3387–3395CrossRefGoogle Scholar
  10. Mao J-D, Schmidt-Rohr K (2004) Accurate quantification of aromaticity and nonprotonated aromatic carbon fraction in natural organic matter by 13C solid-state nuclear magnetic resonance. Environ Sci Technol 38:2680–2684PubMedCrossRefGoogle Scholar
  11. Masiello CA (2004) New directions in black carbon organic geochemistry. Mar Chem 92:201–213CrossRefGoogle Scholar
  12. Ponomarenko EV, Anderson DW (2001) Importance of charred organic matter in black chernozem soils of Saskatchewan. Can J Soil Sci 81:285–297Google Scholar
  13. Raleigh DP, Kolbert AC, Griffin RG (1990) The effect of experimental imperfections on TOSS spectra. J Magn Reson 89:1–9Google Scholar
  14. Schmidt MWI, Skjemstad JO, Gehrt E, Kögel-Knabner I (1999) Charred organic carbon in German chernozemic soils. Eur J Soil Sci 50:351–365CrossRefGoogle Scholar
  15. Simpson MJ, Hatcher PG (2004) Overestimates of black carbon in soils and sediments. Naturwissenschaften 91:436–440PubMedCrossRefGoogle Scholar
  16. Skjemstad JO, Clarke P, Taylor JA, Oades JM, McClure SG (1996) The chemistry and nature of protected carbon in soil. Aust J Soil Res 34:251–271CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Etelvino H. Novotny
    • 1
    • 3
    Email author
  • Michael H. B. Hayes
    • 1
  • Eduardo R. deAzevedo
    • 2
  • Tito J. Bonagamba
    • 2
  1. 1.Chemical and Environmental SciencesUniversity of LimerickIrelandUK
  2. 2.Instituto de Física de São CarlosUniversidade de São PauloSão CarlosBrazil
  3. 3.Embrapa SolosR. Jardim Botânico, 1.024Rio de Janeiro-RJBrazil

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