Dichlorophenolindophenol reduced and becomes colorless, the resultant increase in light transmittance can be measured using a spectrophotometer. DCPIP can also be used as an indicator for vitamin C. If vitamin C, which is a good reducing agent, is present, the blue dye, which turns pink in acid conditions, is reduced to a colorless compound by ascorbic acid. This reaction is a redox reaction: vitamin C (ascorbic acid) is oxidized to dehydroascorbic acid, and DCPIP is reduced to the colorless compound DCPIPH In this titration, when all the ascorbic acid in the solution has been used up, there will not be any
Vitamin C an article by Linus Pauling. Briefly, his position was that for optimal health, humans should be consuming at least 2,300 mg/day to compensate for the inability to synthesize vitamin C. The recommendation also fell into the consumption range for gorillas - a non-synthesizing near-relative to humans. A second argument for high intake is that serum ascorbic acid concentrations increase as intake increases until it plateaus at about 190 to 200 micromoles per liter (µmol/L) once consumption exceeds 1,250 milligrams. As noted, government recommendations are a range of 40 to 110 mg/day and normal plasma is approximately 50 µmol/L, so 'normal'