Determination of Vitamin C Concentration by Titration

Serena Kim
Vasantha Susarla
McGill University

Introduction
This experiment is being performed to determine the concentration of Vitamin C in different solutions by performing a redox reaction with potassium iodate. Vitamin C, which is also called ascorbic acid, can be naturally found in citrus fruits and common vegetables. Vitamin C is considered as an antioxidant because it acts as a coenzyme and reducing agent in several different ways. Also, vitamin C is a necessary nutrient to humans; it is crucial to maintain the connective tissues and bones in the human body (Helmenstine) .
Titration is a method that is used to determine the concentration of a solution by allowing certain volume of analyte to react with other concentration-known solution. It is important to know the point where enough titrant is added to react with the analyte, and this point is called the equivalence point. The equivalence point is shown by an indicator solution, which is a substance that changes color of the titrant at the equivalence point. However, in this experiment we are interested in finding the amount of titrant, rather than the equivalence point.
There are several ways to determine the concentration of vitamin C, and redox reaction is one of the ways to figure out the concentration. An oxidation–reduction reaction starts when iodate ions combines with an acidic solution that contains iodide