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| Titel |
Development of a colorimetric micro-sensor for seawater pH analysis: microfluidic design and oceanic deployment |
| VerfasserIn |
V. M. C. Rérolle, C. F. A. Floquet, M. C. Mowlem, A. J. K. Harris, R. G. J. Bellerby, E. P. Achterberg |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250061000
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| Zusammenfassung |
| Ocean acidification is a serious cause of concern for the marine ecosystems as well as for the
ocean’s capacity to absorb atmospheric CO2. Accurate and precise autonomous in situ pH
sensors deployed on remote platforms are required to study the changes in the ocean’s
carbonate system and their consequences.
The aim of our project is to develop a low cost miniaturized pH system for in situ
long-term deployment. The system is based on the spectrophotometric approach. A simple
micro-fluidic design integrated in a shipboard instrument with low power and reagent
consumption is presented as a key step toward the targeted micro-sensor. A robust optical set
up is achieved with the use of a custom-made polymeric flow cell coupled to a three
wavelength LED. The measurement is made close to in situ temperature (+0.2 Ë C) in the
sampling chamber which has a continuous flow of the ship’s underway seawater
supply.
The system features a short term precision of 0.0008Â pH unit (n=20) and an accuracy
within the range of a certified Tris buffer (0.004 pH units). The pH sensor has been deployed
on RRS Discovery cruises D366 as part of the UK Ocean Acidification Research Program
and D368 as a contribution to GO-SHIP sustained hydrography program. The automated pH
system was operated continuously for a period of two months on an underway seawater
supply.
Technical details of the sensor with an emphasis on the microfluidic design are
presented here as well as the pH data obtained during the cruises D366 and D368. |
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