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Sensing free sulfur dioxide in wine.

Monro TM, Moore RL, Nguyen MC, Ebendorff-Heidepriem H, Skouroumounis GK, Elsey GM, Taylor DK - Sensors (Basel) (2012)

Bottom Line: These processes and others consume the SO(2) over time, resulting in wines with little SO(2) protection.This approach adapts a known colorimetric reaction to a suspended core optical fiber sensing platform, and exploits the interaction between guided light located within the fiber voids and a mixture of the wine sample and a colorimetric analyte.We have shown that this technique enables measurements to be made without dilution of the wine samples, thus paving the way towards real time in situ wine monitoring.

View Article: PubMed Central - PubMed

Affiliation: Institute for Photonics & Advanced Sensing and School of Chemistry & Physics, The University of Adelaide, Adelaide, SA 5005, Australia. tanya.monro@adelaide.edu.au

ABSTRACT
Sulfur dioxide (SO(2)) is important in the winemaking process as it aids in preventing microbial growth and the oxidation of wine. These processes and others consume the SO(2) over time, resulting in wines with little SO(2) protection. Furthermore, SO(2) and sulfiting agents are known to be allergens to many individuals and for that reason their levels need to be monitored and regulated in final wine products. Many of the current techniques for monitoring SO(2) in wine require the SO(2) to be separated from the wine prior to analysis. This investigation demonstrates a technique capable of measuring free sulfite concentrations in low volume liquid samples in white wine. This approach adapts a known colorimetric reaction to a suspended core optical fiber sensing platform, and exploits the interaction between guided light located within the fiber voids and a mixture of the wine sample and a colorimetric analyte. We have shown that this technique enables measurements to be made without dilution of the wine samples, thus paving the way towards real time in situ wine monitoring.

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Scanning electron micrograph (SEM) of the cores of the fabricated F2 glass suspended core optical fibers used for this study. (a) Fiber 1, core diameter 2.1 μm; (b) Fiber 2, core diameter 1.39 μm.
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f2-sensors-12-10759: Scanning electron micrograph (SEM) of the cores of the fabricated F2 glass suspended core optical fibers used for this study. (a) Fiber 1, core diameter 2.1 μm; (b) Fiber 2, core diameter 1.39 μm.

Mentions: The suspended core optical fibers used for this study was fabricated in-house from commercially sourced lead silicate glass (Schott F2 glass) using the billet extrusion and fiber drawing technique [26]. Two different fibers with different core sizes were utilized. Figure 2 shows a scanning electron micrograph (SEM) of the core of the fabricated fibers. The first fiber had an outer diameter of 160 μm and a core diameter of 2.1 μm, Figure 2(a), and the second fiber, Figure 2(b), had an outer diameter of 130 μm and a core diameter of 1.4 μm. Smaller cores enable access to larger light-liquid overlap, and thus higher sensitivity in principle, whilst larger cores offer more straightforward optical coupling and lower loss. The standard absorption of these fibers at 532 nm is approximately 1.12 ± 0.1 dB/m.


Sensing free sulfur dioxide in wine.

Monro TM, Moore RL, Nguyen MC, Ebendorff-Heidepriem H, Skouroumounis GK, Elsey GM, Taylor DK - Sensors (Basel) (2012)

Scanning electron micrograph (SEM) of the cores of the fabricated F2 glass suspended core optical fibers used for this study. (a) Fiber 1, core diameter 2.1 μm; (b) Fiber 2, core diameter 1.39 μm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472855&req=5

f2-sensors-12-10759: Scanning electron micrograph (SEM) of the cores of the fabricated F2 glass suspended core optical fibers used for this study. (a) Fiber 1, core diameter 2.1 μm; (b) Fiber 2, core diameter 1.39 μm.
Mentions: The suspended core optical fibers used for this study was fabricated in-house from commercially sourced lead silicate glass (Schott F2 glass) using the billet extrusion and fiber drawing technique [26]. Two different fibers with different core sizes were utilized. Figure 2 shows a scanning electron micrograph (SEM) of the core of the fabricated fibers. The first fiber had an outer diameter of 160 μm and a core diameter of 2.1 μm, Figure 2(a), and the second fiber, Figure 2(b), had an outer diameter of 130 μm and a core diameter of 1.4 μm. Smaller cores enable access to larger light-liquid overlap, and thus higher sensitivity in principle, whilst larger cores offer more straightforward optical coupling and lower loss. The standard absorption of these fibers at 532 nm is approximately 1.12 ± 0.1 dB/m.

Bottom Line: These processes and others consume the SO(2) over time, resulting in wines with little SO(2) protection.This approach adapts a known colorimetric reaction to a suspended core optical fiber sensing platform, and exploits the interaction between guided light located within the fiber voids and a mixture of the wine sample and a colorimetric analyte.We have shown that this technique enables measurements to be made without dilution of the wine samples, thus paving the way towards real time in situ wine monitoring.

View Article: PubMed Central - PubMed

Affiliation: Institute for Photonics & Advanced Sensing and School of Chemistry & Physics, The University of Adelaide, Adelaide, SA 5005, Australia. tanya.monro@adelaide.edu.au

ABSTRACT
Sulfur dioxide (SO(2)) is important in the winemaking process as it aids in preventing microbial growth and the oxidation of wine. These processes and others consume the SO(2) over time, resulting in wines with little SO(2) protection. Furthermore, SO(2) and sulfiting agents are known to be allergens to many individuals and for that reason their levels need to be monitored and regulated in final wine products. Many of the current techniques for monitoring SO(2) in wine require the SO(2) to be separated from the wine prior to analysis. This investigation demonstrates a technique capable of measuring free sulfite concentrations in low volume liquid samples in white wine. This approach adapts a known colorimetric reaction to a suspended core optical fiber sensing platform, and exploits the interaction between guided light located within the fiber voids and a mixture of the wine sample and a colorimetric analyte. We have shown that this technique enables measurements to be made without dilution of the wine samples, thus paving the way towards real time in situ wine monitoring.

Show MeSH
Related in: MedlinePlus