Experiment 3: Isolation of Chlorophyll from Spinach and Chromatography

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Experiment 3: Isolation of Chlorophyll from Spinach and Chromatography Performed February 14th and 16th
By
Kyle Herzog
Organic Chemistry 344
Section 807
Spring 2012
 

Objective: The purpose of the experiment is to extract pigments from spinach leaves and separate them by column and thin layer chromatography, determining Rf values for the pigments.

Equations: Rf= Distance travelled by a given compound/Distance travelled by a solvent solution

1. Crude- 4.25/5.5= 0.773
2. Carotene- 4.3/5.5= 0.782
3. Mixture- 3.35/5.5= 0.610
4. Chlorophyll- 2.7/5.5= 0.491

Properties:

Name| MF| MW g/mol| MP/BP| State| Color|
Chlorophyll a| C55H72MgN4O5| 893.51| 150-153o C| Solid| Green| Chlorophyll b| C55H70MgN4O6| 907.47| 183-185o C| Solid| Green| Carotene| C40H56| 536.87| 178-179o C| Powder| Yellow|

Chlorophyll a Chlorophyll b Carotene

Procedure:

1. 28.26 g of frozen spinach was obtained and dried with paper towel, then cut up into small pieces and placed in a 400 mL beaker. 2. 25 mL of acetone was added to the spinach and mixed with a glass rod, and then it was left to stand for 5 minutes. 3. The acetone was decanted into a separatory funnel without transferring any spinach leaves by using a powder funnel with a cotton plug. 4. An Erlenmeyer flask was used to press the spinach and 25 mL of acetone was added to the spinach leaves and mixed as before, repeated twice. 5. 25 mL of hexane was added to the separatory funnel and mixed with venting. 6. 25ml of saturated sodium chloride was added to the separatory funnel and mixed. 7. The aqueous layer was collected in a beaker and the organic layer was placed in another layer. 8. The aqueous layer was then extracted with 25 mL of hexane and the organic layers combined. 9. The combined organic layers were then extracted with 25 mL of saturated sodium chloride and discarded the aqueous...
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