Why is NanoSIMS elemental imaging of arsenic in seaweed (Laminaria digitata) important for understanding of arsenic biochemistry in addition of speciation information?

Eleanor Ender, Maria Angels Subirana, Andrea Raab, Eva M. Krupp, Dirk Schaumlöffel, Jörg Feldmann*

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

Brown seaweed such as Laminaria digitata is known to accumulate arsenic at a concentration of more than 100 mg kg -1. How the algae can tolerate such a high level of arsenic has traditionally been studied by arsenic speciation analysis using HPLC-ICPMS, but the knowledge of its molecular forms has not yet given any answers. Here we demonstrate for the first time that the combination of speciation analysis with high resolution imaging by NanoSIMS and TEM identifies not only the molecular structures of arsenic but also the location of arsenic in cells and cell substructures in a brown seaweed species. The majority of 117 mg kg -1 arsenic in L. digitata fronds was in the form of inorganic arsenic (53%) and arsenosugars (32%) and only 1.5% of total arsenic as arsenolipids (mainly as AsHC and AsPL). A lateral resolution of 300 nm and the concentration of arsenic were high enough for the localization of arsenic in the cells of the seaweed using NanoSIMS. The majority of arsenic was found in the cell walls and cell membrane, while the inside of the cell was almost arsenic free, which is not expected if the majority of arsenic species are hydrophilic. The NanoSIMS images question the integrity of the arsenic species during extraction for the speciation analysis and indicate that inorganic arsenic is unlikely to occur freely in the seaweed. Whether inorganic arsenic and the arsenosugars are bound directly to the polymeric carbohydrate alginates or fucoidans in the seaweed is unclear and needs further investigation.

Original languageEnglish
Pages (from-to)2295-2302
Number of pages8
JournalJournal of Analytical Atomic Spectrometry
Volume34
Issue number11
Early online date18 Sep 2019
DOIs
Publication statusPublished - 1 Nov 2019

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Laminaria
Seaweed
Biochemistry
Arsenic
Imaging techniques
Alginates

Keywords

  • ION MASS-SPECTROMETRY
  • ICP-MS
  • RESOLUTION
  • RICE
  • QUANTIFICATION
  • POLYPHOSPHATE

ASJC Scopus subject areas

  • Analytical Chemistry
  • Spectroscopy

Cite this

@article{5d0f8ba37b0d4bdaa4d289b33e71ea5b,
title = "Why is NanoSIMS elemental imaging of arsenic in seaweed (Laminaria digitata) important for understanding of arsenic biochemistry in addition of speciation information?",
abstract = "Brown seaweed such as Laminaria digitata is known to accumulate arsenic at a concentration of more than 100 mg kg -1. How the algae can tolerate such a high level of arsenic has traditionally been studied by arsenic speciation analysis using HPLC-ICPMS, but the knowledge of its molecular forms has not yet given any answers. Here we demonstrate for the first time that the combination of speciation analysis with high resolution imaging by NanoSIMS and TEM identifies not only the molecular structures of arsenic but also the location of arsenic in cells and cell substructures in a brown seaweed species. The majority of 117 mg kg -1 arsenic in L. digitata fronds was in the form of inorganic arsenic (53{\%}) and arsenosugars (32{\%}) and only 1.5{\%} of total arsenic as arsenolipids (mainly as AsHC and AsPL). A lateral resolution of 300 nm and the concentration of arsenic were high enough for the localization of arsenic in the cells of the seaweed using NanoSIMS. The majority of arsenic was found in the cell walls and cell membrane, while the inside of the cell was almost arsenic free, which is not expected if the majority of arsenic species are hydrophilic. The NanoSIMS images question the integrity of the arsenic species during extraction for the speciation analysis and indicate that inorganic arsenic is unlikely to occur freely in the seaweed. Whether inorganic arsenic and the arsenosugars are bound directly to the polymeric carbohydrate alginates or fucoidans in the seaweed is unclear and needs further investigation.",
keywords = "ION MASS-SPECTROMETRY, ICP-MS, RESOLUTION, RICE, QUANTIFICATION, POLYPHOSPHATE",
author = "Eleanor Ender and Subirana, {Maria Angels} and Andrea Raab and Krupp, {Eva M.} and Dirk Schauml{\"o}ffel and J{\"o}rg Feldmann",
note = "Acknowledgements The work was supported by funding from the French “Agence Nationale de la Recherche” via the project ANR-11-EQPX-0027 MARSS. E. E. thanks the EU Erasmus Programme for financial support.",
year = "2019",
month = "11",
day = "1",
doi = "10.1039/C9JA00187E",
language = "English",
volume = "34",
pages = "2295--2302",
journal = "Journal of Analytical Atomic Spectrometry",
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publisher = "The Royal Society of Chemistry",
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TY - JOUR

T1 - Why is NanoSIMS elemental imaging of arsenic in seaweed (Laminaria digitata) important for understanding of arsenic biochemistry in addition of speciation information?

AU - Ender, Eleanor

AU - Subirana, Maria Angels

AU - Raab, Andrea

AU - Krupp, Eva M.

AU - Schaumlöffel, Dirk

AU - Feldmann, Jörg

N1 - Acknowledgements The work was supported by funding from the French “Agence Nationale de la Recherche” via the project ANR-11-EQPX-0027 MARSS. E. E. thanks the EU Erasmus Programme for financial support.

PY - 2019/11/1

Y1 - 2019/11/1

N2 - Brown seaweed such as Laminaria digitata is known to accumulate arsenic at a concentration of more than 100 mg kg -1. How the algae can tolerate such a high level of arsenic has traditionally been studied by arsenic speciation analysis using HPLC-ICPMS, but the knowledge of its molecular forms has not yet given any answers. Here we demonstrate for the first time that the combination of speciation analysis with high resolution imaging by NanoSIMS and TEM identifies not only the molecular structures of arsenic but also the location of arsenic in cells and cell substructures in a brown seaweed species. The majority of 117 mg kg -1 arsenic in L. digitata fronds was in the form of inorganic arsenic (53%) and arsenosugars (32%) and only 1.5% of total arsenic as arsenolipids (mainly as AsHC and AsPL). A lateral resolution of 300 nm and the concentration of arsenic were high enough for the localization of arsenic in the cells of the seaweed using NanoSIMS. The majority of arsenic was found in the cell walls and cell membrane, while the inside of the cell was almost arsenic free, which is not expected if the majority of arsenic species are hydrophilic. The NanoSIMS images question the integrity of the arsenic species during extraction for the speciation analysis and indicate that inorganic arsenic is unlikely to occur freely in the seaweed. Whether inorganic arsenic and the arsenosugars are bound directly to the polymeric carbohydrate alginates or fucoidans in the seaweed is unclear and needs further investigation.

AB - Brown seaweed such as Laminaria digitata is known to accumulate arsenic at a concentration of more than 100 mg kg -1. How the algae can tolerate such a high level of arsenic has traditionally been studied by arsenic speciation analysis using HPLC-ICPMS, but the knowledge of its molecular forms has not yet given any answers. Here we demonstrate for the first time that the combination of speciation analysis with high resolution imaging by NanoSIMS and TEM identifies not only the molecular structures of arsenic but also the location of arsenic in cells and cell substructures in a brown seaweed species. The majority of 117 mg kg -1 arsenic in L. digitata fronds was in the form of inorganic arsenic (53%) and arsenosugars (32%) and only 1.5% of total arsenic as arsenolipids (mainly as AsHC and AsPL). A lateral resolution of 300 nm and the concentration of arsenic were high enough for the localization of arsenic in the cells of the seaweed using NanoSIMS. The majority of arsenic was found in the cell walls and cell membrane, while the inside of the cell was almost arsenic free, which is not expected if the majority of arsenic species are hydrophilic. The NanoSIMS images question the integrity of the arsenic species during extraction for the speciation analysis and indicate that inorganic arsenic is unlikely to occur freely in the seaweed. Whether inorganic arsenic and the arsenosugars are bound directly to the polymeric carbohydrate alginates or fucoidans in the seaweed is unclear and needs further investigation.

KW - ION MASS-SPECTROMETRY

KW - ICP-MS

KW - RESOLUTION

KW - RICE

KW - QUANTIFICATION

KW - POLYPHOSPHATE

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U2 - 10.1039/C9JA00187E

DO - 10.1039/C9JA00187E

M3 - Article

VL - 34

SP - 2295

EP - 2302

JO - Journal of Analytical Atomic Spectrometry

JF - Journal of Analytical Atomic Spectrometry

SN - 0267-9477

IS - 11

ER -