Iodimetric Titration of Vitamin C

Report
By: Chris Lloyd and Katy Salter
Background Information
Needed in the body to form collagen in
the bones
 Absorbed by the body but can not be
stored
 Lack of vitamin C results in Scurvydisease that causes brown spots on the
skins and gums will soften to the point of
possible losing your teeth

Introduction

Tested levels of Vitamin C…
 Time: Day After Purchase vs. 2 Weeks After
 Temp: Room Temperature vs. Fridge
 Storage: Open Container vs. Sealed
What We Did…
Made an Iodine solution
 Titrated 25mL’s of orange juice sample
until the endpoint
 Used 1% starch solution as indicator

What We Used…

Tropicana Orange Juice
 No Pulp, Non Concentrate
Vitamin C = 150% Daily Value
 60 mg Daily
 One Bottle(355mL) = 90 mg
 Theoretical grams of vitamin C per 25mL
sample = 0.006338g or 6.338mg

Vitamin C Levels of Orange Juice
1.6
1.4
1.48
1.48
1.51
1.49
1.4
1.28
Amount of Vitamin C (mg)
1.2
1.22
1
0.8
0.6
0.549
0.4
0.2
0
Day 1, RT,
Opened
Day 1, Fridge,
Opened
Day 1, RT,
Sealed
Day 1, Fridge,
Sealed
2 Weeks, RT,
2 Weeks,
2 Weeks, RT,
2 Weeks,
Opened
Fridge, Opened
Sealed
Fridge, Sealed
Vitamin C Levels of Orange Juice with Theoretical
7
6
6.338
Amount of Vitamin C (mg)
5
4
3
2
1.48
1.48
1.51
1.49
1
1.22
1.28
2 Weeks,
Fridge,
Opened
2 Weeks, RT,
Sealed
1.4
0.549
0
Theoretical
Amount
Day 1, RT, Day 1, Fridge, Day 1, RT, Day 1, Fridge, 2 Weeks, RT,
Opened
Opened
Sealed
Sealed
Opened
2 Weeks,
Fridge,
Sealed
Calculations

Actual Amount of Vitamin C per Sample:


Concentration of Standard=Concentration of Sample
 (26.7/0.2515)=(6.27/x)
 X=0.059g/L
Concentration of Sample x Volume of Sample=Actual grams in Sample

0.059*0.025=0.00148g
Conclusion

Best Way to Store Orange Juice
 Sealed in the fridge

Worst Way
 Opened at room temperature

Two factors that will preserve Vitamin C
 Sealed or in the fridge

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