Skill:
• Separation of photosynthetic pigments by chromatograph
Photosynthetic organisms do not rely on a single pigment to absorb light, but instead benefit from the combined action of many
- These pigments include chlorophylls, xanthophyll and carotenes
Chromatography is an experimental technique by which mixtures can be separated
- A mixture is dissolved in a fluid (called the mobile phase) and passed through a static material (called the stationary phase)
- The different components of the mixture travel at different speeds, causing them to separate
- A retardation factor can then be calculated (Rf value = distance component travels ÷ distance solvent travels)
Two of the most common techniques for separating photosynthetic pigments are:
- Paper chromatography – uses paper (cellulose) as the stationary bed
- Thin layer chromatography – uses a thin layer of adsorbent (e.g. silica gel) which runs faster and has better separation
Overview of the Chomatographic Separation of Photosynthetic Pigments
