Extraction and Identification of Dyes:
Kool Aid
Introduction:
Extraction is a technique commonly used in organic chemistry. It is one of many
techniques used to remove certain chemicals from a mixture. This isolation is done to
purify the desired chemical or to separate it so that it can be identified or studied.
Extraction is often the first step done when a chemist wishes to identify a chemical,
determine its structure, and possibly synthesize it. Artificial vanilla exists because the
natural chemical was isolated and its structure determined. Once the structure was
known, a procedure for producing it more inexpensively in the laboratory was developed.
Solid phase extraction will be used for this procedure. Very small silica beads covered
with C-18 material are packed in the column. A frit is placed above and below the
packing to hold it in place. When a mixture is passed through the column, some
components are more strongly attracted to the C-18 material than others. These
components "stick" to the column and are held while the other components pass through.
By selecting proper solvents, the materials adhered to the column can be removed and
isolated for further study.
Purpose:
To separate and analyze a mixture of dyes using a solid phase extraction tube.
Materials/Equipment:
C-18 solid phase extraction tube
10 mL syringe
100 mL beaker
spoon or stirring rod
Kool-Aid solution
water
isopropanol (5%,10%,20%,70%)
well plate
Safety Considerations:


Always wear goggles in the lab.
Do not drink any of the Kool-Aid solutions. They are contaminated with
alcohol and will make you sick.
ASIM Extraction and Identification of Dyes: Kool Aid
Revised: 2/06
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Procedure:
1. Draw 3 mL of 70% isopropanol into the syringe.
2. Condition the C-18 column to remove any contaminants and "wet" the column. You
do this by attaching the SHORT end of the column to the syringe then expelling the
alcohol through column into the sink.
3. Once you have conditioned the column, repeat the first two steps using water instead
of isopropanol to rinse the isopropanol off the column. Discard the waste into the
sink.
4. Now remove the column from the syringe. Draw 3 mL of the Kool-Aid solution into
the syringe.
5. Replace the SHORT end of the column on the syringe. Slowly begin to expel the
liquid through the column. The first five drops of effluent (liquid that has passed
through the column) are residue from the previous step. This should be expelled into
the sink. Collect the remaining (fresh) effluent in a separate well of the plate.
Observe what is happening in the column. Record your observations in your Data
Table.
6. Repeat steps 4 and 5 using each of the following solutions in the order listed below
instead of Kool-Aid.
5% Isopropanol
10% Isopropanol
20% Isopropanol
70% Isopropanol
7. Continue to add portions of 70% isopropanol until the effluent is colorless.
8. If time permits, repeat the procedure with a different Kool-Aid flavor.
9. When all extractions are complete remove the C-18 column, draw 3 mL of water into
the syringe, replace the SHORT end of the column on the syringe, and expel the
water into the sink.
10. Clean your well plate and your lab station.
11. Return the supplies as directed by your teacher.
ASIM Extraction and Identification of Dyes: Kool Aid
Revised: 2/06
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Name _________________________
Partner’s Name(s) _________________________
Period ______Date_______________
Data:
Name of Kool-Aid #1:
____________________
Solution added
Column Appearance
Color of effluent
Kool-Aid
____________________
____________________
5% isopropanol
____________________
____________________
10% isopropanol
____________________
____________________
20% isopropanol
____________________
____________________
70% isopropanol
____________________
____________________
Name of Kool-Aid #2:
____________________
Solution added
Column appearance
Color of effluent
Kool-Aid
____________________
____________________
5% isopropanol
____________________
____________________
10% isopropanol
____________________
____________________
20% isopropanol
____________________
____________________
70% isopropanol
____________________
____________________
Questions:
1.
Compare the colors you pulled off your column to the actual dyes that make up
the Kool-Aid (from the back of the package.) Do you think that you have
evidence of the dyes used to make the color of your Kool-Aid?
2.
Which dye, if any, do you think makes up most of the color of your Kool-Aid?
Explain your answer.
3.
Which dye had the highest affinity (attraction) to the column? Why?
4.
If two different colors both came through using 10% isopropanol, how would you
change the extraction to separate them?
5.
What do you think should happen if you mixed all of the effluents back together?
ASIM Extraction and Identification of Dyes: Kool Aid
Revised: 2/06
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