Use of synchrotron radiation X‐ray fluorescence and X‐ray absorption spectroscopy to investigate bioaccumulation, molecular target, and biotransformation of volcanic elements

Abstract

Because environment pollutants have a strong impact on ecosystems, including human health, methods of their determination and mitigation have received special attention in recent years. Taking advantage of the wide range of data that can be obtained by synchrotron radiation X‐ray fluorescence spectroscopy (SRXRF) in the field of environmental sciences, different instrumental setups were used to study the biological fates of toxic elements in volcanic environments. The elemental composition of plants, algae, and bacteria in Copahue and Domuyo volcanoes from Argentinean Patagonia was determined by SRXRF and the volcanic elements Ti, Fe, and Zn were abundant in these organisms. Interestingly, a high As concentration was found in cyanobacteria (26.2 μg/g) living in As contaminated stream (250 μg/ml). Because arsenic is toxic and human carcinogen, element‐retention capacity, element‐protein associations, and arsenic metabolism in this As resistant organism were analyzed by SRXRF. A high capacity (100–95%) of Ti > Fe > Cr > Sr > Ni > Cu > Mn > Zn > As retention was found after aqueous/alcoholic extraction assisted by ultrasonication. The cyanobacterial proteins were separated by SDS‐PAGE, electro‐transferred to nitrocellulose, and mapped by SRXRF. Defined protein bands containing Ca, Ti, Mn, Fe, and/or Zn were observed. Their ability to metabolize arsenic was revealed by combining SRXRF and X‐ray absorption near edge spectroscopy and Dimethylarsenic was found. Based on results, we speculate that these cyanobacteria could be interesting candidates for water treatment. Finally, we conclude that SRXRF is a valuable tool to study the biological cycle of environmental pollutants, including their accumulation, molecular targets, and metabolism. The SRXRF may also assist in remediation researches.

Pehuén (Araucaria araucana) seed residues are a valuable source of natural antioxidants with nutraceutical, chemoprotective and metal corrosion-inhibiting properties

“…The phenol and flavonoid content in fresh whole coat was analyzed by HPLC. Considerable peaks were observed in the analysis at 25 °C where gallic acid, with a 31.3% proportion, was the highest, while catechin represented 15.8% of the spectrogram area. Analysis at 40 °C revealed three substantial peaks, where quercetin, with a 67.6% proportion, was the main component.…”

“…Perhaps for these reasons, Araucaria araucana (common name "pehuén", Fig. 1) has been successful in the volcanic environment of the Argentine and Chilean Patagonia, with trees more than 1000 years old [23][24][25][26]. Pehuén forest occupies a total area of approximately 450,000 ha, of which 263,525 ha belong to Chile and 179,289 ha to Argentina [27].…”

Impacts of volcanic eruptions and early recovery in freshwater environments and organisms

“…Volcanic emissions are also important sources of As (Morales-Simfors et al, 2020). In Copahue and Domuyo volcanoes of the Argentinean Patagonia, a high As concentration was observed in Cyanobacteria (26.2 μg g −1 ) living in Ascontaminated streams (250 μg ml −1 ), implying that these organisms have the ability to metabolise As (Lamela et al, 2018).…”

Comprehensive analysis of renal arsenic accumulation using images based on X-ray fluorescence at the tissue, cellular, and subcellular levels

“…The SRTXRF determinations were performed by exciting the samples with a white synchrotron spectrum for 200 seconds. For mapping of elements in freeze-dried kidney sections of 100 µm thick, the samples were set on the horizontal plane at 45 degrees from the incident beam to minimize scattering (conventional incidence geometry: 45-45 degrees), as previously reported (Pérez et al, 2006;Rubio et al, 2008 Pérez et al, 2014;Lamela et al, 2018). Samples were excited by a white beam, which was condensed to spot size of µm in diameter using a glass monocapillary for multielemental mapping according to Pérez et al (2016), and the counting time per point was of seconds.…”