Separation Techniques

Separation Techniques

1. Extraction

   • Like dissolves like
     • water = inorganic salts; ionized species
     • neutral organic compounds
   • Depends on partitioning
     • = the preferential dissolution of a species into one solvent over the other 
   • Aqueous Work-up
     • Removes inorganic materials from the desired organic product
   • usually with two immiscible solvents
     • Aqueous phase
     • Organic phase

2. Chromatography

   • https://www.khanacademy.org/test-prep/mcat/chemical-processes/separations-purifications/a/principles-of-chromatography

3. Distillation

   • Separates liquids based on BP; lower boiling point is boiled off and collected
   • Simple distillation
     • Normal column
     • can separate two liquids if boiling point difference is large
   • Fractional Distillation
     • Fractionating column
     • Can sep two liquids with smaller differences in BP
   • Vacuum Distillation
     • Done under lower pressure (vacuum)
     • Lowers the BP for all liquid components so you don't have to have such high temps
     • Prevents decomposition at high temps.

4. Recrystallization

   • Barely dissolving your compound, then letting it recrystallize out of solution. Solvent in which your solute will dissolve in at warm temps, but not at cool temps. This will make your product more pure