The analysis of dissolved inorganic carbon in liquid using a microfluidic conductivity sensor with membrane separation of CO2
Abstract Autonomous continuous analysis of oceanic dissolved inorganic carbon (DIC) concentration with depth is of great significance with regard to ocean acidification and climate change. However, miniaturisation of in situ analysis systems is hampered by the size, cost and power requirements of tr...
Published in: | Microfluidics and Nanofluidics |
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2020
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Online Access: | http://dx.doi.org/10.1007/s10404-020-02339-1 https://link.springer.com/content/pdf/10.1007/s10404-020-02339-1.pdf https://link.springer.com/article/10.1007/s10404-020-02339-1/fulltext.html |
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crspringernat:10.1007/s10404-020-02339-1 2023-05-15T17:51:53+02:00 The analysis of dissolved inorganic carbon in liquid using a microfluidic conductivity sensor with membrane separation of CO2 Tweedie, M. Sun, D. Gajula, D. R. Ward, B. Maguire, P. D. Invest Northern Ireland Department for Employment and Learning, Northern Ireland Science Foundation Ireland National Science Foundation 2020 http://dx.doi.org/10.1007/s10404-020-02339-1 https://link.springer.com/content/pdf/10.1007/s10404-020-02339-1.pdf https://link.springer.com/article/10.1007/s10404-020-02339-1/fulltext.html en eng Springer Science and Business Media LLC https://creativecommons.org/licenses/by/4.0 https://creativecommons.org/licenses/by/4.0 CC-BY Microfluidics and Nanofluidics volume 24, issue 5 ISSN 1613-4982 1613-4990 Materials Chemistry Condensed Matter Physics Electronic, Optical and Magnetic Materials journal-article 2020 crspringernat https://doi.org/10.1007/s10404-020-02339-1 2022-01-04T07:34:44Z Abstract Autonomous continuous analysis of oceanic dissolved inorganic carbon (DIC) concentration with depth is of great significance with regard to ocean acidification and climate change. However, miniaturisation of in situ analysis systems is hampered by the size, cost and power requirements of traditional optical instrumentation. Here, we report a low-cost microfluidic alternative based on CO 2 separation and conductance measurements that could lead to integrated lab-on-chip systems for ocean float deployment, or for moored or autonomous surface vehicle applications. Conductimetric determination of concentration, in the seawater range of 1000–3000 µmol kg −1 , has been achieved using a microfluidic thin-film electrode conductivity cell and a membrane-based gas exchange cell. Sample acidification released CO 2 through the membrane, reacting in a NaOH carrier, later drawn through a sub-µL conductivity cell, for impedance versus time measurements. Precision values (relative standard deviations) were ~ 0.2% for peak height measurements at 2000 µmol kg −1 . Comparable precision values of ~ 0.25% were obtained using a C4D electrophoresis headstage with similar measurement volume. The required total sample and reagent volumes were ~ 500 µL for the low volume planar membrane gas exchange cell. In contrast, previous conductivity-based DIC analysis systems required total volumes between 5000 and 10,000 µL. Long membrane tubes and macroscopic wire electrodes were avoided by incorporating a planar membrane (PDMS) in the gas exchange cell, and by sputter deposition of Ti/Au electrodes directly onto a thermoplastic (PMMA) manifold. Future performance improvements will address membrane chemical and mechanical stability, further volume reduction, and component integration into a single manifold. Article in Journal/Newspaper Ocean acidification Springer Nature (via Crossref) Microfluidics and Nanofluidics 24 5 |
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Open Polar |
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Springer Nature (via Crossref) |
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crspringernat |
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English |
topic |
Materials Chemistry Condensed Matter Physics Electronic, Optical and Magnetic Materials |
spellingShingle |
Materials Chemistry Condensed Matter Physics Electronic, Optical and Magnetic Materials Tweedie, M. Sun, D. Gajula, D. R. Ward, B. Maguire, P. D. The analysis of dissolved inorganic carbon in liquid using a microfluidic conductivity sensor with membrane separation of CO2 |
topic_facet |
Materials Chemistry Condensed Matter Physics Electronic, Optical and Magnetic Materials |
description |
Abstract Autonomous continuous analysis of oceanic dissolved inorganic carbon (DIC) concentration with depth is of great significance with regard to ocean acidification and climate change. However, miniaturisation of in situ analysis systems is hampered by the size, cost and power requirements of traditional optical instrumentation. Here, we report a low-cost microfluidic alternative based on CO 2 separation and conductance measurements that could lead to integrated lab-on-chip systems for ocean float deployment, or for moored or autonomous surface vehicle applications. Conductimetric determination of concentration, in the seawater range of 1000–3000 µmol kg −1 , has been achieved using a microfluidic thin-film electrode conductivity cell and a membrane-based gas exchange cell. Sample acidification released CO 2 through the membrane, reacting in a NaOH carrier, later drawn through a sub-µL conductivity cell, for impedance versus time measurements. Precision values (relative standard deviations) were ~ 0.2% for peak height measurements at 2000 µmol kg −1 . Comparable precision values of ~ 0.25% were obtained using a C4D electrophoresis headstage with similar measurement volume. The required total sample and reagent volumes were ~ 500 µL for the low volume planar membrane gas exchange cell. In contrast, previous conductivity-based DIC analysis systems required total volumes between 5000 and 10,000 µL. Long membrane tubes and macroscopic wire electrodes were avoided by incorporating a planar membrane (PDMS) in the gas exchange cell, and by sputter deposition of Ti/Au electrodes directly onto a thermoplastic (PMMA) manifold. Future performance improvements will address membrane chemical and mechanical stability, further volume reduction, and component integration into a single manifold. |
author2 |
Invest Northern Ireland Department for Employment and Learning, Northern Ireland Science Foundation Ireland National Science Foundation |
format |
Article in Journal/Newspaper |
author |
Tweedie, M. Sun, D. Gajula, D. R. Ward, B. Maguire, P. D. |
author_facet |
Tweedie, M. Sun, D. Gajula, D. R. Ward, B. Maguire, P. D. |
author_sort |
Tweedie, M. |
title |
The analysis of dissolved inorganic carbon in liquid using a microfluidic conductivity sensor with membrane separation of CO2 |
title_short |
The analysis of dissolved inorganic carbon in liquid using a microfluidic conductivity sensor with membrane separation of CO2 |
title_full |
The analysis of dissolved inorganic carbon in liquid using a microfluidic conductivity sensor with membrane separation of CO2 |
title_fullStr |
The analysis of dissolved inorganic carbon in liquid using a microfluidic conductivity sensor with membrane separation of CO2 |
title_full_unstemmed |
The analysis of dissolved inorganic carbon in liquid using a microfluidic conductivity sensor with membrane separation of CO2 |
title_sort |
analysis of dissolved inorganic carbon in liquid using a microfluidic conductivity sensor with membrane separation of co2 |
publisher |
Springer Science and Business Media LLC |
publishDate |
2020 |
url |
http://dx.doi.org/10.1007/s10404-020-02339-1 https://link.springer.com/content/pdf/10.1007/s10404-020-02339-1.pdf https://link.springer.com/article/10.1007/s10404-020-02339-1/fulltext.html |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_source |
Microfluidics and Nanofluidics volume 24, issue 5 ISSN 1613-4982 1613-4990 |
op_rights |
https://creativecommons.org/licenses/by/4.0 https://creativecommons.org/licenses/by/4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1007/s10404-020-02339-1 |
container_title |
Microfluidics and Nanofluidics |
container_volume |
24 |
container_issue |
5 |
_version_ |
1766159166046470144 |