OCR A
MODULE 6
Chromatography
CHEMISTRY
___
Notes
Chromatography
Separate individual components in a mixture
Stationary phase: does not move, solid or liquid supported on a solid
Mobile phase moves, liquid or gas
Analysis of drugs, plastics, flavourings, air samples, forensics
Thin layer chromatography
How many components in a mixture
TLC plate: plastic sheet or glass, coated with a thin layer of of solid adsorbent silica = stationary
phase
Components have different affinities for the adsorbent and bind with different strengths to its
surface
Adsorption: silica holds substances to its surface
Separation: relative adsorption of substances with the stationary phase
Calculate retention factor (Rf)
Compare Rf with known values recorded using same solvent system and adsorbent
MODULE 6
Chromatography
CHEMISTRY
___
Notes
Chromatography
Separate individual components in a mixture
Stationary phase: does not move, solid or liquid supported on a solid
Mobile phase moves, liquid or gas
Analysis of drugs, plastics, flavourings, air samples, forensics
Thin layer chromatography
How many components in a mixture
TLC plate: plastic sheet or glass, coated with a thin layer of of solid adsorbent silica = stationary
phase
Components have different affinities for the adsorbent and bind with different strengths to its
surface
Adsorption: silica holds substances to its surface
Separation: relative adsorption of substances with the stationary phase
Calculate retention factor (Rf)
Compare Rf with known values recorded using same solvent system and adsorbent
