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

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 300-350 mg/day

Magnesium Deficiency Symptoms

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

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!

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

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

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

Results: Molarities of 2 types of milk Skim milk 2% milk .04180 M Ca2+ .03931 M Ca2+ .03412 M Ca2+ & Mg2+ .03404 M Ca2+ & Mg2+

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

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

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!

DRINK MILK….IT DOES A BODY GOOD!!!

References Harris C. Daniel. Quantitative Chemical Analysis-5th edition. NY: WH Freeman co. 1999 p.310-311 <http://www.whymilk.com/about/nutrient/index.html> <http://www.bodybuilding.com/store/cmz.html> <http://www.notmilk.com> <http://www.gotmilk.com> <http://www.milk.com> McCormick, G. Patrick. “Titration of Calcium and Magnesium in Milk with EDTA” Journal of Chemical Education p.136-139 <http://www.orionres.com/labcat/ise/iseindex.html>