Hi! ^^ . I;m doing my extended essay on chemistry. y research question is " How do storage time and temperature affect the concentration of vitamin C in orange juice". Currently, I 'm doing experiments on the known amount of vitamin C samples and DCPIP. But, after the DCPIP reach it's end point (turn colorless), it eventually turns back to blue, and i'm thinking that it might be that the vitamin C is being oxidised. I have to come up with causes and solution to the problem and i really need your help. I'm thinking that acid would be added to DCPIP to minimize the oxidation but I'm not sure about it. have anyone here done the chemistry EE, please help me !!
...for the 2nd time this year