Show simple item record

dc.contributor.authorGeissler, Felix
dc.contributor.authorAchterberg, Eric P.
dc.contributor.authorBeaton, Alexander D.
dc.contributor.authorHopwood, Mark J.
dc.contributor.authorClarke, Jennifer S.
dc.contributor.authorMutzberg, André
dc.contributor.authorMowlem, Matt C.
dc.contributor.authorConnelly, Douglas P.
dc.identifier.citationGeissler, F., Achterberg, E.P., Beaton, A.D., Hopwood, M.J., Clarke, J.S., Mutzberg, A., Mowlem, M.C. and Connelly, D.P. (2017) Evaluation of a Ferrozine Based Autonomous in Situ Lab-on-Chip Analyzer for Dissolved Iron Species in Coastal Waters. Frontiers in Marine Science, 4:322, 13pp. DOI: 10.3389/fmars.2017.00322en_US
dc.description.abstractThe trace metal iron (Fe) is an essential micronutrient for phytoplankton growth and limits, or co-limits primary production across much of the world’s surface ocean. Iron is a redox sensitive element, with Fe(II) and Fe(III) co-existing in natural waters. Whilst Fe(II) is the most soluble form, it is also transient with rapid oxidation rates in oxic seawater. Measurements of Fe(II) are therefore preferably undertaken in situ. For this purpose an autonomous wet chemical analyzer based on lab-on-chip technology was developed for the in situ determination of the concentration of dissolved (<0.45μm) Fe species (Fe(II) and labile Fe) suitable for deployments in a wide range of aquatic environments. The spectrophotometric approach utilizes a buffered ferrozine solution and a ferrozine/ascorbic acid mixture for Fe(II) and labile Fe(III) analyses, respectively. Diffusive mixing, color development and spectrophotometric detection take place in three separate flow cells with different lengths such that the analyzer can measure a broad concentration range from low nM to several μM of Fe, depending on the desired application. A detection limit of 1.9 nMFe was found. Themicrofluidic analyzer was tested in situ for nine days in shallow waters in the Kiel Fjord (Germany) along with other sensors as a part of the SenseOCEAN EU-project. The analyzer’s performance under natural conditions was assessed with discrete samples collected and processed according to GEOTRACES protocol [acidified to pH < 2 and analyzed via inductively coupled plasma mass spectrometry (ICP-MS)]. The mechanical performance of the analyzer over the nine day period was good (consistent high precision of Fe(II) and Fe(III) standards with a standard deviation of 2.7% (n = 214) and 1.9% (n = 217), respectively, and successful completion of every programmed data point). However, total dissolved Fe was consistently low compared to ICP-MS data. Recoveries between 16 and 75% were observed, indicating that the analyzer does not measure a significant fraction of natural dissolved Fe species in coastal seawater. It is suggested that an acidification step would be necessary in order to ensure that the analyzer derived total dissolved Fe concentration is reproducible and consistent with discrete values.en_US
dc.rightsAttribution 4.0*
dc.subject.otherDissolved iron
dc.titleEvaluation of a Ferrozine Based Autonomous in Situ Lab-on-Chip Analyzer for Dissolved Iron Species in Coastal Waters.en_US
dc.typeJournal Contributionen_US
dc.subject.parameterDisciplineOther inorganic chemical measurementsen_US
dc.bibliographicCitation.titleFrontiers in Marine Scienceen_US
dc.bibliographicCitation.issueArticle 00322en_US
dc.description.adoptionValidated (tested by third parties)en_US
dc.description.sensorsIn situ chemical analyzeren_US
dc.description.methodologyTypeReports with methodological relevanceen_US Geißler

Files in this item


This item appears in the following Collection(s)

Show simple item record

Attribution 4.0
Except where otherwise noted, this item's license is described as Attribution 4.0