Relative proportions of organic carbon functional groups in biochars as influenced by spectral data collection and processing.

Autor: Munira S; Department of Soil Science, Faculty of Agricultural & Food Sciences, University of Manitoba, 362 Ellis Building, Winnipeg, MB, R3T 2N2, Canada. Electronic address: muniras@myumanitoba.ca., Dynes JJ; Canadian Light Source, University of Saskatchewan, 44 Innovation Boulevard, Saskatoon, SK, S7N 2V3, Canada., Islam M; Department of Civil Engineering, Faculty of Engineering, University of Manitoba, E3-257, EITC Building, Winnipeg, MB, R3T 2N2, Canada., Khan F; Department of Soil Science, Faculty of Agricultural & Food Sciences, University of Manitoba, 362 Ellis Building, Winnipeg, MB, R3T 2N2, Canada., Adesanya T; Department of Soil Science, Faculty of Agricultural & Food Sciences, University of Manitoba, 362 Ellis Building, Winnipeg, MB, R3T 2N2, Canada., Regier TZ; Canadian Light Source, University of Saskatchewan, 44 Innovation Boulevard, Saskatoon, SK, S7N 2V3, Canada., Spokas KA; USDA-ARS, 1991 Upper Buford Circle, 439 Borlaug Hall, St Paul, MN, 55108, USA., Farenhorst A; Department of Soil Science, Faculty of Agricultural & Food Sciences, University of Manitoba, 362 Ellis Building, Winnipeg, MB, R3T 2N2, Canada.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2021 Nov; Vol. 283, pp. 131023. Date of Electronic Publication: 2021 Jun 07.
DOI: 10.1016/j.chemosphere.2021.131023
Abstrakt: Solid-state 13 C Nuclear Magnetic Resonance (NMR) and synchrotron-based X-ray Absorption Near-Edge Structure (XANES) have applications for determining the relative proportions of organic C functional groups in materials. Spectral data obtained by NMR is typically processed using integration (INTEG) whereas XANES spectral data is typically processed using deconvolution (DECONV). The objective of this study was to examine the impact of spectral data collection and processing on the estimated relative proportions of organic C functional groups in biochars. Biochars showed large variations in aromatic C (45-97%), alkyl C (0-23%), O-alkyl C (1-41%), phenolic C (0-20%) and carboxylic C (0-20%). NMR had a better ability than XANES to differentiate % aromatic C across biochars, and the mean % aromatic C was always greater for NMR-INTEG and NMR-DECONV than for XANES-INTEG or XANES-DECONV. NMR-INTEG showed significant associations with NMR-DECONV and XANES-INTEG for % aromatic C and alkyl C, but there were no significant associations between NMR and XANES for % O-alkyl C, phenolic C and carboxylic C. As well, there was no association between NMR-INTEG and XANES-DECONV for any organic C functional group, and in some cases, spectral data collection and processing influenced the quantification of organic C functional groups in a given biochar to the extent that the differences observed were as large as differences observed between biochars when analyzed using the same spectral data collection and processing technique. We conclude that great caution must be taken when comparing studies that determined organic C functional groups in materials using NMR-INTEG versus XANES-DECONV.
(Copyright © 2021 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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