Data_Sheet_1_Optical Properties and Photochemical Transformation of the Dissolved Organic Matter Released by Sargassum.docx
Chromophoric dissolved organic matter (CDOM) is the dominant absorber of ultraviolet radiation in the ocean, but its sources within the ocean, as well as its chemical composition, remain uncertain. One source of marine CDOM is Sargassum, an epipelagic marine macro brown alga common to the Gulf of Me...
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ftfrontimediafig:oai:figshare.com:article/13227035 2023-05-15T17:36:28+02:00 Data_Sheet_1_Optical Properties and Photochemical Transformation of the Dissolved Organic Matter Released by Sargassum.docx Leanne C. Powers Rossana Del Vecchio Neil V. Blough Natasha McDonald Philippe Schmitt-Kopplin Michael Gonsior 2020-11-12T05:46:44Z https://doi.org/10.3389/fmars.2020.588287.s001 https://figshare.com/articles/dataset/Data_Sheet_1_Optical_Properties_and_Photochemical_Transformation_of_the_Dissolved_Organic_Matter_Released_by_Sargassum_docx/13227035 unknown doi:10.3389/fmars.2020.588287.s001 https://figshare.com/articles/dataset/Data_Sheet_1_Optical_Properties_and_Photochemical_Transformation_of_the_Dissolved_Organic_Matter_Released_by_Sargassum_docx/13227035 CC BY 4.0 CC-BY Oceanography Marine Biology Marine Geoscience Biological Oceanography Chemical Oceanography Physical Oceanography Marine Engineering Sargassum CDOM optical properties photochemistry FT-ICR MS pH titration marine DOM Dataset 2020 ftfrontimediafig https://doi.org/10.3389/fmars.2020.588287.s001 2020-11-18T23:58:21Z Chromophoric dissolved organic matter (CDOM) is the dominant absorber of ultraviolet radiation in the ocean, but its sources within the ocean, as well as its chemical composition, remain uncertain. One source of marine CDOM is Sargassum, an epipelagic marine macro brown alga common to the Gulf of Mexico, Caribbean, and Western North Atlantic. Furthermore, Sargassum contains phlorotannins, a class of polyphenols that may have similar optical properties to terrestrial polyphenols. Here, we analyze Sargassum CDOM optical properties, acquired from absorption and fluorescence spectra of filtered samples collected during Sargassum exudation experiments in seawater tanks. To further evaluate the structural basis of Sargassum CDOM optical properties, Sargassum CDOM was collected by solid phase extraction (SPE) and its chemical composition was tested by pH titration and sodium borohydride reduction. These chemical tests revealed that Sargassum CDOM absorption spectra respond similarly to pH titration and borohydride reduction when compared to terrestrially-derived materials, but Sargassum CDOM has unique absorbance peaks in difference spectra that have not been observed in terrestrially-derived CDOM. These absorbance features are consistent with the deprotonation of modified Sargassum phlorotannins, which are likely highly related phenolic acids and polyphenols. Sargassum CDOM was also more rapidly photodegraded when compared to terrestrial CDOM such as Suwannee River Natural Organic Matter. Similar to terrestrial DOM, ultrahigh resolution mass spectrometry revealed that sunlight decreases relative abundances of m/z ions and molecular formulas with an average O/C ratio of 0.6 and an average H/C ratio of 0.9, suggesting preferential photodegradation and/or phototransformation of hydrogen-deficient and oxygenated compounds, such as Sargassum phlorotannins. Assuming a large fraction of Sargassum CDOM is quickly mineralized to CO 2 during its rapid photodegradation, Sargassum could play a major role in marine photochemical ... Dataset North Atlantic Frontiers: Figshare Suwannee River ENVELOPE(-100.046,-100.046,56.125,56.125) |
institution |
Open Polar |
collection |
Frontiers: Figshare |
op_collection_id |
ftfrontimediafig |
language |
unknown |
topic |
Oceanography Marine Biology Marine Geoscience Biological Oceanography Chemical Oceanography Physical Oceanography Marine Engineering Sargassum CDOM optical properties photochemistry FT-ICR MS pH titration marine DOM |
spellingShingle |
Oceanography Marine Biology Marine Geoscience Biological Oceanography Chemical Oceanography Physical Oceanography Marine Engineering Sargassum CDOM optical properties photochemistry FT-ICR MS pH titration marine DOM Leanne C. Powers Rossana Del Vecchio Neil V. Blough Natasha McDonald Philippe Schmitt-Kopplin Michael Gonsior Data_Sheet_1_Optical Properties and Photochemical Transformation of the Dissolved Organic Matter Released by Sargassum.docx |
topic_facet |
Oceanography Marine Biology Marine Geoscience Biological Oceanography Chemical Oceanography Physical Oceanography Marine Engineering Sargassum CDOM optical properties photochemistry FT-ICR MS pH titration marine DOM |
description |
Chromophoric dissolved organic matter (CDOM) is the dominant absorber of ultraviolet radiation in the ocean, but its sources within the ocean, as well as its chemical composition, remain uncertain. One source of marine CDOM is Sargassum, an epipelagic marine macro brown alga common to the Gulf of Mexico, Caribbean, and Western North Atlantic. Furthermore, Sargassum contains phlorotannins, a class of polyphenols that may have similar optical properties to terrestrial polyphenols. Here, we analyze Sargassum CDOM optical properties, acquired from absorption and fluorescence spectra of filtered samples collected during Sargassum exudation experiments in seawater tanks. To further evaluate the structural basis of Sargassum CDOM optical properties, Sargassum CDOM was collected by solid phase extraction (SPE) and its chemical composition was tested by pH titration and sodium borohydride reduction. These chemical tests revealed that Sargassum CDOM absorption spectra respond similarly to pH titration and borohydride reduction when compared to terrestrially-derived materials, but Sargassum CDOM has unique absorbance peaks in difference spectra that have not been observed in terrestrially-derived CDOM. These absorbance features are consistent with the deprotonation of modified Sargassum phlorotannins, which are likely highly related phenolic acids and polyphenols. Sargassum CDOM was also more rapidly photodegraded when compared to terrestrial CDOM such as Suwannee River Natural Organic Matter. Similar to terrestrial DOM, ultrahigh resolution mass spectrometry revealed that sunlight decreases relative abundances of m/z ions and molecular formulas with an average O/C ratio of 0.6 and an average H/C ratio of 0.9, suggesting preferential photodegradation and/or phototransformation of hydrogen-deficient and oxygenated compounds, such as Sargassum phlorotannins. Assuming a large fraction of Sargassum CDOM is quickly mineralized to CO 2 during its rapid photodegradation, Sargassum could play a major role in marine photochemical ... |
format |
Dataset |
author |
Leanne C. Powers Rossana Del Vecchio Neil V. Blough Natasha McDonald Philippe Schmitt-Kopplin Michael Gonsior |
author_facet |
Leanne C. Powers Rossana Del Vecchio Neil V. Blough Natasha McDonald Philippe Schmitt-Kopplin Michael Gonsior |
author_sort |
Leanne C. Powers |
title |
Data_Sheet_1_Optical Properties and Photochemical Transformation of the Dissolved Organic Matter Released by Sargassum.docx |
title_short |
Data_Sheet_1_Optical Properties and Photochemical Transformation of the Dissolved Organic Matter Released by Sargassum.docx |
title_full |
Data_Sheet_1_Optical Properties and Photochemical Transformation of the Dissolved Organic Matter Released by Sargassum.docx |
title_fullStr |
Data_Sheet_1_Optical Properties and Photochemical Transformation of the Dissolved Organic Matter Released by Sargassum.docx |
title_full_unstemmed |
Data_Sheet_1_Optical Properties and Photochemical Transformation of the Dissolved Organic Matter Released by Sargassum.docx |
title_sort |
data_sheet_1_optical properties and photochemical transformation of the dissolved organic matter released by sargassum.docx |
publishDate |
2020 |
url |
https://doi.org/10.3389/fmars.2020.588287.s001 https://figshare.com/articles/dataset/Data_Sheet_1_Optical_Properties_and_Photochemical_Transformation_of_the_Dissolved_Organic_Matter_Released_by_Sargassum_docx/13227035 |
long_lat |
ENVELOPE(-100.046,-100.046,56.125,56.125) |
geographic |
Suwannee River |
geographic_facet |
Suwannee River |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
doi:10.3389/fmars.2020.588287.s001 https://figshare.com/articles/dataset/Data_Sheet_1_Optical_Properties_and_Photochemical_Transformation_of_the_Dissolved_Organic_Matter_Released_by_Sargassum_docx/13227035 |
op_rights |
CC BY 4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.3389/fmars.2020.588287.s001 |
_version_ |
1766135963864530944 |