Flash column equilibration – is it a waste of time or necessary step?

Flash column chromatography has been practiced by chemists since the 1970s. That practice required the silica in the column be properly wetted to remove trapped gasses to ensure uniform flow (remember those days of not letting air into the column?). Today, with automated flash chromatography systems and pre-packed cartridges as the norm, chemists ask me – do I really need to pre-equilibrate my cartridge?

In this post I explore the impact on chromatography that equilibration, and lack thereof, has on separation performance.

Read about it now!

Published by

Bob Bickler

Technical Specialist, Biotage

3 thoughts on “Flash column equilibration – is it a waste of time or necessary step?”

  1. Can someone please tell me if this impact RF…
    I am new to HPLC and had to equilibrate Waters c18 3.5×150 column for the first time
    Mobile phase A is 20mM ammonium acetate
    Mob B is 100%Acn
    I have equilibrated column with mob B at the flow rate 0.1 ml a min for 12 h with required t of the column
    Then ranked it up to0.6 slowly changing flow every 20 min or so
    Then introduced mob A at 40%
    Then changed to 95% as required
    Could someone tell me if this ok?my RF is a bit on a low side
    Thanks

    1. Hi Anna,

      Mobile phase A is your weak solvent. If you want to begin the elution gradient at 40%A (= 60%B), then this needs to be your equilibration solvent. Then you can build your gradient to increase mobile phase B to 95%.You should be able to flow at 0.5 mL/min during the entire process and not change flow during the run.

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