Vitamin C Test

You can use starch-iodine in place of DCPIP to test vitamin C.

Mechanism:
The ascorbic acid reduces the iodine to iodide so it no longer forms the starch-iodine complex.

Procedure:
1ml of starch is placed in a suitable receptacle and 1 drop of iodine solution added.

The ascorbic acid solution is then added drop wise until the blue-black colour of the starch iodine complex disappear to leave a colourless solution.