Experiment 6.1 Paper Chromatography
Purpose: To separate a mixture of dyes in water/alcohol solvent
1. Prepare the Chromatography Strips
Cut the filter paper into strips that are about 5 cm x 8 cm. If the beakers are tall enough you can make the strips longer to allow for more separation. The longer the strips are the longer it will take to develop them.
Draw a line lightly with the pencil across the strips 2 cm above the bottom edge and 2 cm from the top of the strip.
Label the strip with the corresponding solution that it will be placed in.
Spot each Sharpie pen on the starting line. For better results spot a pen, let it dry and spot it again on top of the first spot. Keep the spots small and space them out as much as possible so that the colors will not run together as they separate.
2. Developing the Chromatograms
- Place the strips in the beakers. Make sure the solution does not come above the starting line. If you need to, remove some of the solution. If you use a thin filter paper you may need to support the strips to keep them from sliding down into the solution as they get wet. Depending on the type of cover used for your beakers, you can either tape the top of the strip to a pencil sitting on top of the beaker or tape the strip to the sides of the beaker. Cover the beakers and let the strips develop until the ascending solution front is about 2 cm from the top of the strip.
-Remove the strips and let them dry on a paper towel.
3. Observing the Chromatograms
Look at the chromatograms and observe:
How the spots of dye separated in water solvents compared to alcohol solvent
What colors are each of the dyes made of?