1. Quantitative Analysis of Vitamin C Contained in Foods

2. Vitamin C
Vitamin C is also known as ascorbic acid. Its absence from our bodies results in deficiency disorders such as scurvy.

3. Today we will… Titrate a fruit drink with iodine.
Calculate the amount of vitamin C in our fruit drink.
Remember that a solution with dissolved Vitamin C should not be exposed to air for long periods. Prolonged exposure causes oxidation of the ascorbic acid.

4. The titration
As we titrate our fruit drink with iodine, the vitamin C (ascorbic acid) is oxidized by the iodine.
I2 + starch → iodine – starch complex (blue/purple)
When there is no more vitamin C to be oxidized, there will be an excess of iodine. This iodine will combine with the starch to make a blue/purple solution.

5. (Remember stoichiometry? )
Calculations
To calculate the amount of vitamin C in your fruit drink you will use the amount of iodine titrated and the following conversion factor.
1 mL of I2 (0.01 M) = 1.76 mg vitamin C
(Remember stoichiometry? )

6. Potential Health Concerns
Inhalation: corrosion, coughing, choking, inflammation of the upper respiratory system, pulmonary edema, circulatory failure and death
Ingestion: corrosion, pain and burns of the mouth, throat, esophagus and gastrointestinal tract, nausea, vomiting, diarrhea and death
Skin contact: irritation, corrosion, redness, pain, burns, ulcers, sensitization, allergic reaction and discoloration of the skin
Eye contact: corrosion, burns and permanent eye damage
Tumorigen, mutagen and reproductive effectors