Lab-on-chip analyser for the in situ determination of dissolved manganese in seawater.

Geißler, Felix, Achterberg, Eric P. , Beaton, Alexander D., Hopwood, Mark J. , Esposito, Mario, Mowlem, Matt C., Connelly, Douglas P. and Wallace, Douglas W.R. (2021) Lab-on-chip analyser for the in situ determination of dissolved manganese in seawater. Open Access Scientific Reports, 11 . Art.Nr. 2382. DOI 10.1038/s41598-021-81779-3.

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Supplementary data:

Abstract

A spectrophotometric approach for quantification of dissolved manganese (DMn) with 1-(2-pyridylazo)-2-naphthol (PAN) has been adapted for in situ application in coastal and estuarine waters. The analyser uses a submersible microfluidic lab-on-chip device, with low power (~ 1.5 W) and reagent consumption (63 µL per sample). Laboratory characterization showed an absorption coefficient of 40,838 ± 1127 L⋅mol−1⋅cm−1 and a detection limit of 27 nM, determined for a 34.6 mm long optical detection cell. Laboratory tests showed that long-term stability of the PAN reagent was achieved by addition of 4% v/v of a non-ionic surfactant (Triton-X100). To suppress iron (Fe) interferences with the PAN reagent, the Fe(III) masking agents deferoxamine mesylate (DFO-B) or disodium 4,5-dihydroxy-1,3-benzenedisulfonate (Tiron) were added and their Fe masking efficiencies were investigated. The analyser was tested during a deployment over several weeks in Kiel Fjord (Germany), with successful acquisition of 215 in situ data points. The time series was in good agreement with DMn concentrations determined from discretely collected samples analysed via inductively coupled plasma mass spectrometry (ICP-MS), exhibiting a mean accuracy of 87% over the full deployment duration (with an accuracy of > 99% for certain periods) and clear correlations to key hydrographic parameters.

Document Type: Article
Research affiliation: OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-CH Chemical Oceanography
NOC
OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-CH Chemical Oceanography > FB2-CH Water column biogeochemistry
Main POF Topic: PT6: Marine Life
Refereed: Yes
Open Access Journal?: Yes
Publisher: Nature Research
Projects: HOSST, OCEANSensor
Date Deposited: 01 Feb 2021 10:00
Last Modified: 07 Feb 2024 15:39
URI: https://oceanrep.geomar.de/id/eprint/51702

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