VitE无水乙醇硝酸变橙红色
Vitamin E (VitE) is a fat-soluble antioxidant commonly found in plant-based oils, nuts, and seeds. When VitE is dissolved in anhydrous ethanol (ethyl alcohol without water), it can react with nitric acid to produce a characteristic orange-red color.
This reaction occurs because nitric acid oxidizes the VitE molecule, creating a compound called 2,3,5,6-tetramethyl-1,4-dihydroquinone (TMDQ). TMDQ has a distinct orange-red color and is responsible for the color change observed when VitE reacts with nitric acid.
It is important to note that this reaction only occurs when VitE is dissolved in anhydrous ethanol and exposed to nitric acid. If there is any water present in the ethanol, the reaction will not occur as efficiently, and the color change may not be as noticeable.
Overall, the observation of an orange-red color when VitE and anhydrous ethanol are mixed with nitric acid is a reliable indicator of the presence of VitE in a sample, and can be used in analytical chemistry applications to quantify the amount of VitE present.