Limits...
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.

Show MeSH
Maximum absorbance values obtained as a function of time for three concentrations of sulfites in solution. Hollow data points illustrate the maximum absorbance value obtained.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3472855&req=5

f6-sensors-12-10759: Maximum absorbance values obtained as a function of time for three concentrations of sulfites in solution. Hollow data points illustrate the maximum absorbance value obtained.

Mentions: The color development of the final solution was analyzed as a function of time. In order to investigate the color development, equal volumes of working solution (300 μL of 6.24 × 10−4 mol/L PRA) and model wine samples were combined, diluted to a final volume of 3 mL and allowed to develop in-cuvette using a small magnetic stirrer for mixing. Absorbance measurements were taken at 2 minutes intervals, and the highest absorbance value obtained at each time point were plotted against the development time for 3 concentrations of model wine solutions (Figure 6). This graph illustrates that color development is essentially complete by 10 minutes for these solutions. Consequently, a development time of 10 minutes was used.


Sensing free sulfur dioxide in wine.

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

Maximum absorbance values obtained as a function of time for three concentrations of sulfites in solution. Hollow data points illustrate the maximum absorbance value obtained.
© Copyright Policy
Related In: Results  -  Collection

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

f6-sensors-12-10759: Maximum absorbance values obtained as a function of time for three concentrations of sulfites in solution. Hollow data points illustrate the maximum absorbance value obtained.
Mentions: The color development of the final solution was analyzed as a function of time. In order to investigate the color development, equal volumes of working solution (300 μL of 6.24 × 10−4 mol/L PRA) and model wine samples were combined, diluted to a final volume of 3 mL and allowed to develop in-cuvette using a small magnetic stirrer for mixing. Absorbance measurements were taken at 2 minutes intervals, and the highest absorbance value obtained at each time point were plotted against the development time for 3 concentrations of model wine solutions (Figure 6). This graph illustrates that color development is essentially complete by 10 minutes for these solutions. Consequently, a development time of 10 minutes was used.

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