Observing Paper Chromatography

Paper chromatography is a simple technique used to separate mixtures (like ink or plant pigments) into their individual components based on their solubility in a solvent and attraction to filter paper. The mixture travels up the paper via capillary action, with faster-moving components separating from slower ones to create a "chromatogram"

Materials Needed:

• Chromatography paper (or filter paper cut into strips)
• Water-soluble markers (black, green, or brown work best)
• Solvent (Water for markers)
• Gas jar
• Pencil
• Tape or a pencil to hang the strip

Procedure:

1. Prepare the Paper: Cut the paper into a strip and use a pencil to draw a straight line about 2 cm from the bottom (baseline).
2. Spot the Sample: Place a small dot of the marker ink in the center of the pencil line. Keep the spot small to prevent smearing.
3. Set Up the Solvent: Pour a small amount of water into the beaker, ensuring the water level is below the pencil line so the ink doesn't dissolve directly into it.
4. Develop the Chromatogram: Suspend the paper in the beaker so the bottom tip touches the water.

Observation:  As water rises up the paper, it carries the dyes at different speeds, separating them. Learners observe different colored dyes ispots in the chromatogram.

Learners enjoyed the activity and understood chromatography.