1.3 Chromatography

• Chromatography


  A method of separating dissolved substances that are all in the same solution
• The solutes are separated from the solvent by mass, with heavier substances appearing towards the bottom of the paper
• Solvent


  Liquid into which solute dissolves
• Solute


  Solid which dissolves into a solvent
• Solution


  The product of a solute dissolved in a solvent
• Dissolve


  Solute particles spreading out into a solvent
• Comparing with known sample

  We can compare the spots with known samples to identify things
• Rf Value


  Retention factor = Distance travelled by sample / Distance travelled by solvent front
• Locating agent


  A chemical which binds to separated solutes and makes them visible
• The baseline must be drawn in pencil, or the ink will dissolve and ruin the experiment
• The solvent level must be below the level of the baseline, or the sample will dissolve into the solvent
• The sample to be tested must be placed on the baseline, not in the solvent!
• Comparing with known sample

  
• X contains 3 compounds

  Y contains 2 compounds

  X contains dye 2 and 3

  Y contains dye 2 and 3

  Neither sample contains dye 1

  
• Mobile Phase


  the mixture that is dissolved in a substance
• Stationary Phase


  A solid or liquid on a fixed solid support

  Chromatography = Paper