1. Determination of Calcium and Magnesium in 2% milk vs. Skim Milk
By: Meghana Mehta
2% clover green spring clover green
reduced fat milk spring skim milk

2. Background info on calcium and magnesium
essential to proper formation of bone and teeth
adult RDA is 1000mg/day
MAGNESIUM
regulates nerve and muscle cell functions
adult RDA is mg/day

3. Magnesium Deficiency Symptoms

4. Calcium Deficiency Symptoms
Bone thinning
Osteomalacia-reduction of mineralization of bone

5. Goal of experiment?
To use EDTA titration method to compare the amount of calcium and magnesium in 2 % milk vs. skim milk!
To find out if the % daily allowance of Ca in skim and 2 % milk matches the amount found experimentally!

6. How do EDTA titrations work?
EDTA is a titrant that can be used
It is a hexaprotic ion
Works by binding to metal ions
HO2CCH2 CH2CO2H
HNCH2CH2NH
2 REACTIONS….
Ca2+ + EDTA Ca[EDTA]4-
-Magnesium works the same way

7. Hypothesis??
1.That there is the same amount of calcium and magnesium in both 2% and skim milk
2. The % daily value in skim and 2% milk should correspond after doing calculations
Chart shows % Daily value on the back of the milk carton

8. Procedure as follows: For calcium determination
made calcium standard using CaCO3
standardized EDTA solution against it
performed titrations with calcium standard and Hydroxynapthol blue as indicator
blue violet
Magnesium and calcium determination
made standard EDTA solution
titrated milk samples with EDTA and Erichrome Black T indicator
wine red blue

9. Results: Molarities of 2 types of milk
Skim milk 2% milk
M Ca M Ca2+
M Ca2+ & Mg M Ca2+ & Mg2+

10. Av. % for 2% MILK = 37.85% Do known % values correspond to ones found experimentally Av. % for SKIM MILK = 40.25%

11. Conclusion
Both 2% and skim milk have roughly the same amount of calcium
Both have the same amount of total calcium and magnesium
they are both just as good to drink
the % daily values match up within 10%-explained by experimental error perhaps

12. OTHER METHODS Ion selective electrode
another way to measure ion concentration
most widely used analytical technique
fast and effective
Stuck to one method rather than 2!

13. DRINK MILK….IT DOES A BODY GOOD!!!

14. References
Harris C. Daniel. Quantitative Chemical Analysis-5th edition. NY: WH Freeman co p
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McCormick, G. Patrick. “Titration of Calcium and Magnesium in Milk with EDTA” Journal of Chemical Education p
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