chromatography

• chromatography is the separation of mixtures
• radical chromatography

  This is done by adding water onto a spot of ink in the centre of a piece of filter paper. The pigments separate as they move outwards from the centre, rather than moving upwards as in standard chromatography.
• standard chromatography

  1. draw a horizontal line across the paper
  2. place a small dot of coloured mixture on the line
  3. add spots of pure coloured pigment to compare
  4. lower the piece of paper into the paper into the beaker
  5. observe the solvent
• chromatography is a separation technique used for separating mixtures of soluble substances
• soluble substances are often coloured like food colouring, ink, dyes or plant colouring
• chromatograms can be used to match known pigments with those in a mixture
• on chromatograms, one spot means a piece is pure. An impure substance produces 2 or more spots
• a chromatogram shows the number of pigments of each food colouring contain
• when a solution contains one or more dissolved substance, they can be separated by using chromatography
• the more soluble the higher up the paper the ink goes
• there are 2 types of chromatography; standard chromatography and radical chromatography