Paper Chromatography

Alonzo L. Stallings            Teachers Acad. For Math and Science
6318 South Campbell Ave.       10 West 35th Street
Chicago IL 60629               Chicago IL 60616
(312)434-4204                  (312)808-0100

Objective:

This laboratory experiment is for middle school students.
The students will learn and understand the separation of color in a mixture 
using a liquid or solvent through a solid material, such as paper.  This leads 
to a separation of the various pigments and at the same time can help the 
students make some really creative art work. 

Materials Needed:
                        
Strips of absorbent paper                  Colored Magic Marker
round filter paper                         distilled water
250-ml beaker                              Isopropyl alcohol 
Black Magic Marker                         Acetone or phosphate buffer

Strategy:

Fold a strip of the absorbent paper in a large beaker, so that it will just 
touch the bottom and hang over the top edge.  Take the paper out and across the 
width of the paper about 2 inches from the bottom of the paper, place a thick 
mark with a BLACK MAGIC MARKER.  Now add a small amount of water to the beaker 
to a depth of about 1/2 of an inch, and carefully place the strip into the beaker 
containing the water.  The mark should NOT be in the solution but rather be 
about 1 inch above the water.  Make sure, though, that the end of the paper is 
in the water.  Watch the water as it moves up the strip of paper (due to 
capillary action), and see what happens as it comes in contact with the black 
mark.  Leave the strip in the solution until the water has climbed all the way 
to the crease at the top.  You can leave it until later and proceed with Part B. 
When this is complete, remove the strip of paper and place it somewhere on your 
desk so that it can dry thoroughly. 

Performance Assessment:

The students will be observed to see if they are active participants in the 
experimental process.  I will review the experiment through an oral discussion
with the students.

Conclusions:

This experiment was geared for students to have fun with paper chromatography
and to determine which colors are really in the different solvents that were
used.

References:

FUN WITH CHEMISTRY; Laboratory Experiences for Middle School Students.  The
Institute for Chemical Education at the University of Wisconsin 1990.