1.3.16 Describe how to investigate the vitamin C content of food and drink.

1) Pipette 1 cm3 of 1% DCPIP solution into a test tube.

2) Record the start volume of 1% vitamin C solution in a pipette or burette. 

3) Add 1% vitamin C solution drop by drop to the DCPIP solution.

4) After adding each drop, shake the tube gently.

5) Continue to add drops of the vitamin C solution until the blue color of the DCPIP has just disappeared.

6) Record the end volume. 

7) Calculate the exact volume of 1% vitamin C solution needed to decolorize the DCPIP by subtracting the start volume from the end volume. 

8) Repeat the procedure and average the result.