chromatography

• mobile phase: where molecules can move (liquid or gas)
• stationary phase: where the molecules can't move (solid or liquid on solid support)
• thin layer chromatography: mobile phase is a solvent, stationary phase is a thin layer of solid
• thin layer chromatography method:

  • draw pencil line and spot mixture
  • dip bottom into solvent below spot
  • different substances move up at different rates
  • mark distance each solvent has moved (solvent front) in pencil
  • calculate Rf value
• Rf value equation

  $Rf value=$$\frac{distance travelled by spot}{distance travelled by solvent}$
• adsorption: attraction between a substance and the surface of the stationary phase
• strongly adsorbed, moves slower, won't travel as far
• chromatography- separate molecules
• mass spectrometry- identify molecule