1. Examining Elements in Cereals A Real World Project By Nicole Dixon and Amanda Lagace

2. Purpose The purpose of our experiment was to analyze the mineral content in cereal products in order to make a comparison to the reported values. The content analyses of sodium, potassium, magnesium, calcium, copper, iron, and zinc were performed by the ICP-OES, and the analyses of iron and zinc were performed again using the AA. We analyzed the content using a calibration curve made from standards of various concentrations, and the cereal products we analyzed were Cheerios, Total, Oatmeal Crisp, and Cocoa Puffs.

3. Method We began this procedure by creating 1L of 0.1M nitric acid to use as a solvent. We then created standards for the experiment. We made standards from the sodium, potassium, magnesium, calcium, copper, iron, and zinc stock solutions in concentrations of 10ppm, 20ppm, 30ppm, 40ppm, and 50ppm in 100mL volumetric flasks with nitric acid. We also set aside a blank of nitric acid for analysis. We then created our cereal samples for analysis. We first crushed 0.1g of cereal with a mortar and pestle and dissolved it in 100mL of nitric acid. We used a stir plate for several minutes in order to dissolve most of the sample. What could not be dissolved we filtered out of the solution with filter paper. We ran the blank, standards, and samples on the ICP for the presence of the seven elements. We used the information from the standard to create a calibration curve in order to determine the concentration of the elements in the samples. We then ran the blank, standards, and samples on the AA for the presence of zinc and iron, using the information from the standards again to create a calibration curve to determine the sample concentrations. We used the concentration determined by experimentation to compare to the reported values on the cereal boxes and we calculated the percent difference between the two.

4. Data Cereal Samples Massed Out Cheerios0.101 g Total0.1064 g Oatmeal Crisp0.1012 g Cocoa Puffs0.1016 g

5. Data-AA AA Data SampleAbsorbance 10 ppm0.209 20 ppm0.425 30 ppm0.640 40 ppm0.882 50 ppm0.850 Oatmeal Crisp0.162 Cheerios0.260 Total0.021 Cocoa Puffs0.019 SampleAbsorbance 10 ppm0.610 20 ppm1.805 30 ppm1.860 40 ppm1.888 50 ppm1.917 Oatmeal Crisp1.732 Cheerios0.183 Total0.080 Cocoa Puffs0.117 Iron Zinc Iron: Zinc

6. AA Calibration Curves

7. Data-ICP SampleCa Int. (c/s)Cu Int. (c/s)Fe Int. (c/s)K Int. (c/s)Mg Int. (c/s)Na Int. (c/s)Zn Int. (c/s) 10 ppm297534528152343714633244016001172474420913 20 ppm499390163703717698941136893722144804603284 30 ppm734161096232109049135359510516473381446767545 40 ppm9354119122977141546155636912216864200734837377 50 ppmN/A143857184411190845814951575395084907003 Oatmeal Crisp620447486.013596.01398445557574254511474 Cheerios1408208240.001890.9286040643448707874006.0 Total10086059186.063185.2166009729968972224970.9 Cocoa Puffs1432715140.701288.6122246372508964782056.0

8. ICP Calibration Curves

9. ICP Calibration Curves (cont)

12. Even More Data CheeriosTotalOatmeal CrispCocoa Puffs Sodium160mg140mg125mg150mg Potassium170mg90mg190mg70mg Calcium100mg1000mg20mg100mg Iron6.75mg15mg7.5mg3.75mg Zinc3.75mg15mgNot reported3.75mg Magnesium35mg21mg35mg14mg CopperNot reported 0.04mg Reported values of elements in one serving of each cereal product: CheeriosTotalOatmeal CrispCocoa Puffs Sodium5.771ppm4.965ppm2.108ppm5.644ppm Potassium6.132ppm3.192ppm3.205ppm2.634ppm Calcium3.607ppm35.467ppm0.3373ppm3.763ppm Iron0.2435ppm0.532ppm0.1265ppm0.1411ppm Zinc0.3527ppm0.532ppm0.5903ppm0.1411ppm Magnesium1.2625ppm0.7448ppmNot reported0.5268ppm CopperNot reported 0.0015ppm Calculated theoretical values of elements in 0.1g of cereal in 100mL of solvent based on reported values

13. Sample Calculations Example Calculations of Theoretical Values:

14. Calculations Used ICP (Calibration Curves from Instrument Nay= 108758x + 51823.3 Ky= 44295.1x + 2010.58 Cay= 246238x + 67399.6 Fey= 3423.14x + 242.967 Mgy= 37115.8x + 2944.18 Zny= 24438.6x + 171.203 Cuy= 2809.82x + 64.584 AA (Calibration Curves from Excel) Fey= 0.0124x + 0.0795 Zny= 0.027x + 0.8069

15. Results Cheerios – ICP ElementConcentration (ppm) % Difference Na7.530130.48% K6.41224.57% Ca5.445250.96% Fe0.481497.70% Mg1.654331.03% Zn0.156955.51% Cu0.0625--- Cheerios – AA ElementConcentration (ppm) % Difference Fe1.546338.33% Zn12.54835053.05%

16. Results Total - ICP ElementConcentration (ppm) % Difference Na7.773256.56% K3.702415.52% Ca40.686914.72% Fe0.859561.56% Mg1.8874153.41% Zn0.196463.08% Cu0.0432--- Total - AA ElementConcentration (ppm) % Difference Fe.675927.05% Zn1.013590.51%

17. Results Oatmeal Crisp - ICP ElementConcentration (ppm) % Difference Na6.3510201.28% K3.11172.911% Ca2.2460565.88% Fe0.9795674.31% Mg1.4180140.22% Zn0.4625--- Cu0.14998--- Oatmeal Crisp - AA ElementConcentration (ppm) % Difference Fe14.6336080.63% Zn7.8185---

18. Results Cocoa Puffs - ICP ElementConcentration (ppm) % Difference Na7.766424.38% K2.71443.05% Ca5.544747.35% Fe0.3055116.51% Mg0.924375.46% Zn0.077145.36% Cu0.0271170.04% Cocoa Puffs - AA ElementConcentration (ppm) % Difference Fe0.9885600.57% Zn0.9170549.9%

19. Conclusions The best results came from Potassium. The cereal with the lowest percent differences overall was Cheerios. The cereal with the worst numbers was Oatmeal Crisp. The worst results elementally was iron. Most of the elements with higher percent differences were those with lower reported concentrations in the cereals.

20. What Went Wrong (Possibly) Dissolving the flaky cereals. Filtering the cereals. Concentrations of standards. Low concentration of cereal in the samples. (Used 0.1g in 100 mL) Difference between ICP and AA.