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Purification Techniques CHEM241-06A - Coggle Diagram

- - - - Liquid-Liquid Extraction
        -seperatory funnel allows separation from aqueous and organic solutions, due to differences in density, with lowest density on top of the funnel and highest density on the bottom of the funnel
        1) Add Solutions to top of funnel
        2) Place stopper on top of funnel with fingers on both sides and shake the funnel away fro body and partner, making sure to relieve stopcock when inverted to not have built up pressure
        3) When no more gas is being let out of stopcock, place the funnel on an iron ring and let layers separate
        4i) If experiment wants the bottom layer of seperatory funnel, take off stopper and release stop cock, placing the lower solution in a flask (make sure to leave couple drops of bottom layer in the separatory funnel to not contaminate desired product
        4ii) If experimenter wants to isolate top layer in the separatory funnel, drain lower layer and make sure to allow one or two drops of desired, top layer to go into the flask
- - - - A technique used to separate mixtures of compounds based on their polarities and affinities for a stationary phase and a mobile phase.
      - Used when: impure mixtures (liquids or solids) have compounds with different polarities
    - - Mobile phase (solvent and sample mixture) travels through stationary/fixed phase (adsorbent solid) and each compound elutes at different times (polar compounds elute last because of the greater affinity for the polar stationary phase)
      - Procedure Overview
        
        Preparing the sample (form a slurry with the compounds and evaporate to a dry solid)
        
        Packing the Column (assemble column on ring stand, add stationary phase and first solvent)
        
        Loading the column (add sample mixture and rinse with first solvent)
        
        Elution and Flash Chromatography (for each compound, add corresponding mobile phase and collect as it elutes)
      - More polar mobile phases are chosen for more polar compounds to elute ("bring down") the sample
      - Stationary phases used: silica gel or aluminum (very polar)
    - - Cons
        
        A lengthy form of separation
        
        Low separation power relative to advanced separation methods
        
        More expensive because of higher quantities of solvents needed
      - Pros
        
        Can separate broad variety of mixtures
        
        Broad range of mobile phases
        
        Can separate in large quantities
        
        Analytes can be separated and reused