Paper Chromatography: Principles and Procedure
Paper chromatography is a powerful analytical technique used to separate and identify components in chemical mixtures. The method relies on the differential movement of substances through a stationary phase filterpaper when carried by a mobile phase solvent.
Definition: Chromatography is an analytical technique that separates mixture components based on their different rates of movement through a medium under the influence of a mobile phase.
Vocabulary: Solvent - The liquid phase that carries the mixture components through the filter paper.
The detailed procedure for paper chromatography involves several critical steps:
- Preparation of the filter paper by drawing a pencil line near the bottom
- Application of the sample ink on the pencil line
- Setting up the chromatography chamber with appropriate solvent
- Allowing the separation to occur
- Drying and analyzing the results
Highlight: The choice of best solvents for paper chromatography experiments depends on the compounds being separated - water works well for some substances, while others require ethanol.
Example: When separating ink components, different dyes will travel up the paper at different rates, creating distinct colored bands or spots.
Quote: "Each different dye in the ink will move up the paper at a different rate so the dyes will separate out."
The final chromatogram shows separated components as distinct spots or bands, with insoluble components remaining at the baseline. This pattern serves as a unique chemical fingerprint for the analyzed mixture.
