CHEM 1030L
Fundamentals of Chemistry Laboratory
Pre-lab Review – Paper Chromatography of Amino Acids
Prepare for Laboratory
1. Review the following textbook section(s)
9.1 – Solutions
16.1 – Proteins and Amino Acids
16.2 – Amino acids as acids and bases
2. Review the background and procedure for this lab that are posted online.
3. Be able to work the following textbook problems.
9.5, 16.3, 16.5, 16.7
4. Be able to summarize the purpose of the experiment.
Two or three sentences summarizing what you will do, what you expect to learn, and what
chemical or scientific principles you expect to understand better. Imagine what you would tell
your roommate over a breakfast of Pop-Tarts about what you will be doing in lab that day.
5. Know and be able to do the following.
a. Calculate Rf from spot height data
b. Determine the identity of spots based on data similar to the problem in #6, below.
c. Know the safety and waste disposal considerations for the experiment.
d. Define or briefly explain the following terms
 mobile phase
 eluent
 stationary phase
 visualization
 chromatography
 like dissolves like
 solute
 solvent
6. Example questions
a. What is the stationary phase used in this experiment?
b. Name two materials used in this experiment that are health hazards.
c. Name two ways that acetic acid is hazardous to health.
d. Name two items that must be kept in the fume hood at all times in order to prevent
exposure to acetic acid fumes.
e. Why must gloves be used when handling the chromatogram?
f. What kind of writing instrument must be used to mark the chromatogram?
g. Compounds that are very soluble in the mobile phase will not travel far up the
chromatogram. True or False?
h. Nonpolar solutes are soluble in polar solvents. True or False?
i. During elution, the mobile phase must climb to the very top of the chromatogram. True or
False?
j. Name two things that can cause the chromatogram to elute improperly.
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k. Sucrose is a polar compound. Is it more likely to be soluble in carbon tetrachloride (a
nonpolar solvent) or water (a polar solvent)?
l. What part of the amino acid determines whether it is polar, non-polar, acidic, or basic.
m. Write the formula used to calculate Rf.
n. Distances are to be measured to how many decimal places of cm?
o. The measurements made
on the chromatogram
pictured at right resulted in
the data in the following
table.
i. Calculate the Rf for each spot. (Answers are at bottom.)
ii. Use the Rf and Observations to identify the two spots in the Unknown Sample.
Sample
ID
Name
Spot
Height
(cm)
Solvent
Height
(cm)
Observations
Include spot color(s) and other observations
A
Compound A
2.5
8.4
Light gray spot with dark gray center
B
Compound B
1.5
8.2
Light gray spot with darkest area
slightly above the center of the spot
C
Compound C
5.3
8.1
Uniform light gray spot
2.2
8.0
Light gray spot with dark gray center
5.1
8.0
Uniform light gray spot
Unk1
Unk2
Unknown Sample
spot #1
Unknown Sample
spot #2
Answers
6.o.i. 0.30, 0.18, 0.65, 0.28, 0.64
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6.o.ii. A, C
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