Temperature Time

[WK]

Has anyone studied how long it takes for a typical column to equilibrate to its working temperature?
When changing columns I have a 10minute solvent wash then a 15minute equilibration step before injection of standards etc. I assume the column is stable by then since my baseline is stable and RSD is OK over 5 injections.
My column will be at ambient before installation (22-23degC) and hopefully at 40degC after the 25minutes in a PE200 Series Peltier Oven.
I suppose the amount of Stainless Steel is the determining factor.
Anyone studied this as part of validation perhaps?
WK

[David Blais]

I have never done a validation on how long it takes for a column to come to temperature, but what you are doing seems fine if your RSD and baseline are fine. I would also look at the RT and RRT of analytes, since they can also be critically affected by temperature changes.

BTW, I typicall give about 20-25 minutes for a column to equilibrate to temp after the column heater has reached the set temp.

[Consumer Products Guy]

As soon as I start purging my pump/lines (takes 20 minutes) at start up, I install correct column and raise column temperature to the temperature to be used, so it's already at desired temperature when purging is complete. Add to that 15 minutes to equilibrate the column with mobile phase, and I'm ready. Some HPLC systems (Agilent 1050) can heat but cannot cool, so they can overshoot temperature and need to drift down, where some (Agilent 1100) can also cool so are faster at this.

[WK]

Thanks for your replies!
Consumer Products Guy:
I used to operate an HP1050 column heater that very occasionally used to overshoot temperature but never was serious error. A very robust system.

[Consumer Products Guy]

Yes 1050s are very good; when we changeover Methods during an automated which have different column temperatures, we make sure to set the sequence delay to 20 minutes to ensure that the new column temperature has been reached and equilibrated or the system will shut down due to a Not Ready error. Of course the 20 minutes also gives a decent time for column equilibration with a new mobile phase as well.

[Consumer Products Guy]

that is: automated sequence

[DR]

I have one method where resolution is tied closely to temperature, so I would be inclined to suggest monitoring the resolution between your critical peak pair. You pretty much have to know what will go wrong if the temperature is off and watch that...