Lab Report Extracting Lipids from Ground Nutmeg

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Lab Report Extracting Lipids from Ground Nutmeg

I. Introduction

In this experiment, lipids from ground nutmeg are extracted using a combination of solvents and identify the lipids through chromatography. The purpose of using solvent combinations is to elute the lipids based on their polarity to binding of the silica gel. The chromatography is performed on a silica gel plate and the use of iodine to visualize the lipids. By calculating the Rf values for each compound and comparing them to the known lipids, we are able to distinguish the lipids within the grounded nutmeg.

II. Procedures

Add 5 g crushed nutmeg and 50 mL hexane-isopropanol into a flask and warm for 15 minutes.

Remove the extra solvent on a steam bath under a hood while flushing the flask with N2 gas, leaving the crude extract. Weigh extract.

Prepare silica gel column. Add 6 g of silica gel in 20 mL of hexane to make a slurry. Block column with small piece of glass wool, add 5 mL of hexane and then add the silica slurry up to the 10 cm mark.

Prepare .05 to .075 g of crude lipid by dissolving it in hexane. Add to the silica gel slurry in the column.

Begin collecting samples with the pure hexane. Keep adding hexane so that the silica gel column does not run dry. Collect one 20 ml sample. Repeat with 90:10 hexane and collect 4 20-mL bottles. Repeat with 80:20 hexane and collect 2 20-mL samples.

Analyze each fraction by spotting 10 times with capillary tubes on a TLC plate, which is exposed to iodine vapor for 15 minutes.

III. Results

Lipids Distance Traveled Rf - Correct Results

Rf = Distance Solute Traveled / Distance Solvent Traveled (mm)

Hexane- 0

Hexane 90:10- 123/140 = .879

Hexane 90:10- 39/141= .277

Hexane 90:10- 38/141= .270

Hexane 90:10- 0

Hexane 80:20- 20/139= .863

Hexane 80:20- 19/139= .137

Triolein- 107/137= .78

Oleic Acid- 44/143= .309

Cholesteryl Linolet- 141/142= .99

Crude Lipid- (10 spots)

0, .035, .063, .092, .155, .204, .303, .45, .669, .99

Lipids Distance Traveled Rf - Incorrect Results

Hexane- 0

Hexane 90:10 (All 4 samples)- 0

Hexane 80:20 (Both Samples)- 0

Triolene- 85/149= .570

Oleic Acid- 55/149= .369

Cholesteryl Linolet- 150/150= 1

Crude Lipid- 15 spots

IV. Discussion

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