Thin-Layer Chromo

• What is the sheet coated in

  Silica or alumina
• Material of the sheet

  Plastic, metal or glass
• Describe the process

  Draw pencil line at the bottom of sheet, add a small drop of sample, place sheet in beaker containing solvent, cover beaker, solvent rises up plate with sample, sample separates
• What is the moving phase?

  Whatever moves the component
• What is the stationary phase

  Whatever the moving phase moes through
• Polar and non-polar

  Low retention, component moves further, high solubility, travels more, less adsorbed stationary phase, more time spent till dissolved in moving phase
• Polar-polar

  High retention, low solubility, travel less, most of the time adsorbed in stationary phase, less time on moving phase,
• Factors that affect movement up the plate?

  Retention by stationary phase, solubility in moving phase
• Another factor

  Whether component and stationary phase are both polar and could form hydrogen bonds
• High retention

  Less distance covered up sheet
• Less retention

  More distance covered up the sheet
• How do we make invisible components visible

  Spray chromatogram with a developing agent, add UV light at stationary phase
• If component ends up near solvent front

  Rf value is close to 1
• Non-polar stationary phase and polar component

  Hight Rf value, lower retention time, high solubility