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Published on: September 17, 2016
Visual inspection of acidic pH and bisulfite in white wine using a colorimetric and fluorescent probe
Dan Zhang1, Sifan Wang1, Fangxi Yang1
1School of Chemical Engineering, Sichuan University, Chengdu 610065, China.
Abstract:
The acidic pH and total amount of SO2 are both important quality control indexes of wine, but conventional detection techniques depend heavily on specialized instrument and professional staff, thus are not available to general customers. In this paper, a hemicyanine-based colorimetric and fluorescent probe Hcy-Py was designed and synthesized. It responded to bisulfite selectively with a LOD of 0.68 μM and responded to proton with a pKa of 3.78. Upon the treatment of solutions with different pH values and concentrations of bisulfite, the probe-loaded paper strips displayed distinct color changes under both natural light and UV lamp. When a real white wine sample was subjected to the paper strip experiment, pH as well as bisulfite concentration could be determined by naked-eye quickly and conveniently, thus a visual detection of acidic pH and bisulfite in white wine without involving any sophisticated instrument or professional skill was successfully demonstrated.
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