Most plants contain several pigment molecules, so experiment with different leaves to see the wide range of pigments.
Time Required: 2 hours
- Take 2-3 large leaves (or the equivalent with smaller leaves), tear them into tiny pieces, and place them into small jars with lids.
- Add enough alcohol to just cover the leaves.
- Loosely cover the jars and set them into a shallow pan containing an inch or so of hot tap water.
- Let the jars sit in the hot water for at least a half hour. Replace the hot water as it cools and swirl the jars from time to time.
- The jars are 'done' when the alcohol has picked up color from the leaves. The darker the color, the brighter the chromatogram will be.
- Cut or tear a long strip of coffee filter paper for each jar.
- Place one strip of paper into each jar, with one end in the alcohol and the other outside of the jar.
- As the alcohol evaporates, it will pull the pigment up the paper, separating pigments according to size (largest will move the shortest distance).
- After 30-90 minutes (or until the desired separation is obtained), remove the strips of paper and allow them to dry.
- Can you identify which pigments are present? Does the season in which the leaves are picked affect their colors?
- Try using frozen chopped spinach leaves.
- Experiment with other types of paper.
- You can substitute other alcohols for the rubbing alcohol, such as ethyl alcohol or methyl alcohol.
- If your chromatogram is pale, next time use more leaves and/or smaller pieces to yield more pigment.
What You Need
- Baby Food Jars with Lids
- Rubbing Alcohol
- Coffee Filters
- Hot Water
- Shallow Pan
- Kitchen Utensils