溶剂红 23 MSDSSudan Red
Sudan III changes its color from orange to blue against a small volume of sulfuric acid, and the acetonitrile solution of Sudan III is the most suitable for observing the color-change phenomenon. H-NMR and UV-Vis spectroscopic studies show that the color-change mechanism of Sudan III against sulfuric acid is due to the protonation of the dye by sulfuric acid.