Transcript QUANTITATIVE ANALYSIS OF VITAMIN C CONTAINED IN FOODS Vitamin C http://swampie.files.wordpress.com/ 2008/07/blueberries2.jpg http://bxdhealth.com/UploadFiles/ http://www.thecnj.com/review/2008/0717 2009111623319870.jpg 08/images/strawberries.jpg Vitamin C is also known as ascorbic acid.

QUANTITATIVE
ANALYSIS OF
VITAMIN C
CONTAINED IN
FOODS
Vitamin C
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2008/07/blueberries2.jpg
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http://www.thecnj.com/review/2008/0717
2009111623319870.jpg
08/images/strawberries.jpg
Vitamin C is also known as ascorbic acid. Its absence
from our bodies results in deficiency disorders such as
scurvy.
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.
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d1AookI/AAAAAAAAAS8/m9BqTeIUGuk/s1600/titr
ation-equipment1.jpg
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.
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? )
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