8. Separating Molecules

Chromatography:

• used to separate stuff in a mixture
• once separated you can identify the components
• it can separate out and identify biological molecules e.g. amino acids, carbohydrates, vitamins and nucleic acids
• there are different types- thin layer and paper chromotography

How does it work?

• a mobile phase- where the molecules can move, this is a liquid solvent, such as ethanol or water
• a stationery phase- where the molecules can't move. in paper chromatography this is a piece of chromatography paper. in thin layer this is a thin layer of solid (0.1-0.3mm thick) e.g. silica gel, on a glass plate.
• they all use the same basic principle:
  • the mobile phase moves through/ on the stationary phase
  • the components spend different amounts of time in the mobile and stationery phase
  • the components that spend longer…