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Effect of heat exchange capillary length on retention time
Posted: Thu Sep 18, 2014 5:41 am
by SamNas
What is the effect of length of heat exchange capillary on retention time
Re: Effect of heat exchange capillary length on retention ti
Posted: Thu Sep 18, 2014 7:31 am
by bunnahabhain
Depends a lot on column dimensions and flow rate.
If you go from 3 uL to 12 uL you will have little to no effect on a 250x4.6 mm column with flow rate 2 mL/min but noticeable effect on a 50x2 mm column with 0.2 mL/min.
Re: Effect of heat exchange capillary length on retention ti
Posted: Thu Sep 18, 2014 9:41 am
by SamNas
Will RT increase or decrease if length of heat exchange capillary is increased?
Re: Effect of heat exchange capillary length on retention ti
Posted: Thu Sep 18, 2014 10:02 am
by bunnahabhain
Increased lenght means increased extra column volume, therefore it will also increase the RT.
Re: Effect of heat exchange capillary length on retention ti
Posted: Tue Sep 23, 2014 4:37 pm
by lmh
I suppose what SamNas might also be hinting at is whether the actual temperature-pre-equilibration will be affected by the length of the heat-exchange capillary, and what that will do to retention times.
I have no idea, but at 2mL/min the time spent by solvent in a 3uL capillary is less than a tenth of a second, so I suppose it's possible the solvent isn't going to be fully equilibrated?