Chromatography

• What is chromatography used for?

  To separate and identify component molecules of a mixture

  
• What are the two phases involved in chromatography?

  The mobile phase and the stationary phase

  
• What is the role of the mobile phase in chromatography?

  It allows molecules to move over or through the stationary phase

  
• What forms can the mobile phase take in chromatography?

  It can be in the form of a liquid or a gas

  
• How does solubility affect the movement of products in chromatography?

  More soluble products move further with the mobile phase

  
• What is the stationary phase in chromatography?

  A substance that has affinity to molecules in the mixture being analysed

  
• What does a greater affinity to the stationary phase indicate about a molecule's movement?

  The molecule will move a shorter distance with the mobile phase
• What is an Rf value?

  A value unique to each component molecule in the mixture being analysed
• How is the Rf value calculated?

  By comparing the distance moved by the mobile phase and the molecule

  
• What are the four main types of chromatography?

  1. Thin-Layer Chromatography
  2. Column Chromatography
  3. Gas Chromatography
  4. GC-MS (Gas Chromatography-Mass Spectrometry)
• What is the process in Thin-Layer Chromatography?

  A metal plate is coated with silica and solvent moves up the plate

  
• Why is the plate dried in Thin-Layer Chromatography?

  To reduce toxic fumes

  
• How can chemical traces be viewed in Thin-Layer Chromatography?

  Using a UV lamp or a developing agent like iodine
• What is the setup for Column Chromatography?

  A vertical column is packed with a solid, powdered substance
• How does the mobile phase work in Column Chromatography?

  A solvent containing the mixture moves down the column

  
• What does the varying affinities of molecules in Column Chromatography allow for?

  They drain out of the column at different times

  
• What is retention time in Column Chromatography?

  The time taken for a molecule to drain out of the column
• What is the purpose of Gas Chromatography?

  To separate mixtures of volatile liquids
• What is the mobile phase in Gas Chromatography?

  A high pressure gas
• How does the analysis machine in Gas Chromatography work?

  It records a retention time for each component molecule
• What does GC-MS combine?

  Gas chromatography and mass spectrometry

  
• What is the advantage of using GC-MS?

  It produces more accurate results for molecule analysis
• How does GC-MS improve the analytical process?

  It is a much faster analytical process
• What are the key features of GC-MS?

  • Combines gas chromatography and mass spectrometry
  • Allows for advanced molecule analysis
  • Provides accurate identification of molecules
  • Faster than traditional methods