Location, speciation, and quantification of carbon in silica phytoliths using synchrotron scanning transmission X-ray microspectroscopy.

Autor: Negrao DR; Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, Brazil.; Department of Agronomy, Kansas State University, Manhattan, KS, United States of America., Cezar JC; Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, Brazil., Montoro FE; Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, Brazil., Wang J; Canadian Light Source (CLS), Saskatoon, SK, Canada., Rice CW; Department of Agronomy, Kansas State University, Manhattan, KS, United States of America., Driemeier CE; Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, Brazil.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2024 Apr 15; Vol. 19 (4), pp. e0302009. Date of Electronic Publication: 2024 Apr 15 (Print Publication: 2024).
DOI: 10.1371/journal.pone.0302009
Abstrakt: Phytoliths of biogenic silica play a vital role in the silicon biogeochemical cycle and occlude a fraction of organic carbon. The location, chemical speciation, and quantification of this carbon within phytoliths have remained elusive due to limited direct experimental evidence. In this work, phytoliths (bilobate morphotype) from the sugarcane stalk epidermis are sectioned with a focused ion beam to produce lamellas (≈10 × 10 μm2 size, <500 nm thickness) and probed by synchrotron scanning transmission X-ray microspectroscopy (≈100-200 nm pixel size; energies near the silicon and carbon K-absorption edges). Analysis of the spectral image stacks reveals the complementarity of the silica and carbon spatial distributions, with carbon found at the borders of the lamellas, in islands within the silica, and dispersed in extended regions that can be described as a mixed silica-carbonaceous matrix. Carbon spectra are assigned mainly to lignin-like compounds as well as to proteins. Carbon contents of 3-14 wt.% are estimated from the spectral maps of four distinct phytolith lamellas. The results provide unprecedented spatial and chemical information on the carbon in phytoliths obtained without interference from wet-chemical digestion.
Competing Interests: The authors have declared that no competing interests exist.
(Copyright: © 2024 Negrao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
Databáze: MEDLINE
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