A new colorimetric DET technique for determining mm-resolution sulfide porewater distributions and allowing improved interpretation of iron(II) co-distributions

Nadeeka Rathnayake Kankanamge, William W. Bennett, Peter R. Teasdale, Jianyin Huang, David T. Welsh*

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Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

Measurement of sulfide in pore waters is critical for understanding biogeochemical processes, especially within coastal sediments. Here we report the development of a new colorimetric DET (diffusive equilibration in thin films) technique for determining mm-resolution, two-dimensional sulfide distributions in sediment pore waters. This colorimetric sulfide DET method was based on the standard spectrophotometric methylene blue assay, but modified to allow quantitation of sulfide by computer imaging densitometry. The method detection and effective upper measurement limits of the optimised technique were 3.7 and 1000 μmol L−1, respectively. The optimised sulfide DET method was combined with the colorimetric iron(II) DET method to obtain co-distributions in coastal seagrass (Zostera muelleri) colonised sediment under light and dark conditions. In the dark, seagrass sediments were more reduced than in the light, with large areas being dominated by high porewater sulfide concentrations. These co-distributions were compared with those obtained using the previously described DET-DGT (diffusive gradients in thin films) method for measuring iron(II) and sulfide co-distributions. There was less overlap of iron(II) and sulfide distributions using the sulfide DET as the two DET methods are influenced most by the later hours of deployment, whereas the sulfide-DGT measurement integrates concentrations over the whole deployment period. Overlap was most apparent in very dynamic sediment zones, such as burrow wall sediments.

OriginalsprogEngelsk
Artikelnummer125388
TidsskriftChemosphere
Vol/bind244
ISSN0045-6535
DOI
StatusUdgivet - apr. 2020

Fingeraftryk

porewater
sulfide
iron
sediment
seagrass
distribution
coastal sediment
detection method
burrow
method
assay

Citer dette

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title = "A new colorimetric DET technique for determining mm-resolution sulfide porewater distributions and allowing improved interpretation of iron(II) co-distributions",
abstract = "Measurement of sulfide in pore waters is critical for understanding biogeochemical processes, especially within coastal sediments. Here we report the development of a new colorimetric DET (diffusive equilibration in thin films) technique for determining mm-resolution, two-dimensional sulfide distributions in sediment pore waters. This colorimetric sulfide DET method was based on the standard spectrophotometric methylene blue assay, but modified to allow quantitation of sulfide by computer imaging densitometry. The method detection and effective upper measurement limits of the optimised technique were 3.7 and 1000 μmol L−1, respectively. The optimised sulfide DET method was combined with the colorimetric iron(II) DET method to obtain co-distributions in coastal seagrass (Zostera muelleri) colonised sediment under light and dark conditions. In the dark, seagrass sediments were more reduced than in the light, with large areas being dominated by high porewater sulfide concentrations. These co-distributions were compared with those obtained using the previously described DET-DGT (diffusive gradients in thin films) method for measuring iron(II) and sulfide co-distributions. There was less overlap of iron(II) and sulfide distributions using the sulfide DET as the two DET methods are influenced most by the later hours of deployment, whereas the sulfide-DGT measurement integrates concentrations over the whole deployment period. Overlap was most apparent in very dynamic sediment zones, such as burrow wall sediments.",
keywords = "Computer imaging densitometry, Diffusive equilibration in thin films, Diffusive gradients in thin films, Environmental variability, High-resolution distributions, Sediment biogeochemistry",
author = "Kankanamge, {Nadeeka Rathnayake} and Bennett, {William W.} and Teasdale, {Peter R.} and Jianyin Huang and Welsh, {David T.}",
year = "2020",
month = "4",
doi = "10.1016/j.chemosphere.2019.125388",
language = "English",
volume = "244",
journal = "Chemosphere",
issn = "0045-6535",
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A new colorimetric DET technique for determining mm-resolution sulfide porewater distributions and allowing improved interpretation of iron(II) co-distributions. / Kankanamge, Nadeeka Rathnayake; Bennett, William W.; Teasdale, Peter R.; Huang, Jianyin; Welsh, David T.

I: Chemosphere, Bind 244, 125388, 04.2020.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - A new colorimetric DET technique for determining mm-resolution sulfide porewater distributions and allowing improved interpretation of iron(II) co-distributions

AU - Kankanamge, Nadeeka Rathnayake

AU - Bennett, William W.

AU - Teasdale, Peter R.

AU - Huang, Jianyin

AU - Welsh, David T.

PY - 2020/4

Y1 - 2020/4

N2 - Measurement of sulfide in pore waters is critical for understanding biogeochemical processes, especially within coastal sediments. Here we report the development of a new colorimetric DET (diffusive equilibration in thin films) technique for determining mm-resolution, two-dimensional sulfide distributions in sediment pore waters. This colorimetric sulfide DET method was based on the standard spectrophotometric methylene blue assay, but modified to allow quantitation of sulfide by computer imaging densitometry. The method detection and effective upper measurement limits of the optimised technique were 3.7 and 1000 μmol L−1, respectively. The optimised sulfide DET method was combined with the colorimetric iron(II) DET method to obtain co-distributions in coastal seagrass (Zostera muelleri) colonised sediment under light and dark conditions. In the dark, seagrass sediments were more reduced than in the light, with large areas being dominated by high porewater sulfide concentrations. These co-distributions were compared with those obtained using the previously described DET-DGT (diffusive gradients in thin films) method for measuring iron(II) and sulfide co-distributions. There was less overlap of iron(II) and sulfide distributions using the sulfide DET as the two DET methods are influenced most by the later hours of deployment, whereas the sulfide-DGT measurement integrates concentrations over the whole deployment period. Overlap was most apparent in very dynamic sediment zones, such as burrow wall sediments.

AB - Measurement of sulfide in pore waters is critical for understanding biogeochemical processes, especially within coastal sediments. Here we report the development of a new colorimetric DET (diffusive equilibration in thin films) technique for determining mm-resolution, two-dimensional sulfide distributions in sediment pore waters. This colorimetric sulfide DET method was based on the standard spectrophotometric methylene blue assay, but modified to allow quantitation of sulfide by computer imaging densitometry. The method detection and effective upper measurement limits of the optimised technique were 3.7 and 1000 μmol L−1, respectively. The optimised sulfide DET method was combined with the colorimetric iron(II) DET method to obtain co-distributions in coastal seagrass (Zostera muelleri) colonised sediment under light and dark conditions. In the dark, seagrass sediments were more reduced than in the light, with large areas being dominated by high porewater sulfide concentrations. These co-distributions were compared with those obtained using the previously described DET-DGT (diffusive gradients in thin films) method for measuring iron(II) and sulfide co-distributions. There was less overlap of iron(II) and sulfide distributions using the sulfide DET as the two DET methods are influenced most by the later hours of deployment, whereas the sulfide-DGT measurement integrates concentrations over the whole deployment period. Overlap was most apparent in very dynamic sediment zones, such as burrow wall sediments.

KW - Computer imaging densitometry

KW - Diffusive equilibration in thin films

KW - Diffusive gradients in thin films

KW - Environmental variability

KW - High-resolution distributions

KW - Sediment biogeochemistry

UR - http://www.scopus.com/inward/record.url?scp=85075791312&partnerID=8YFLogxK

U2 - 10.1016/j.chemosphere.2019.125388

DO - 10.1016/j.chemosphere.2019.125388

M3 - Journal article

C2 - 31809928

AN - SCOPUS:85075791312

VL - 244

JO - Chemosphere

JF - Chemosphere

SN - 0045-6535

M1 - 125388

ER -