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2 ml/min for a 3um particle size column?
Posted: Tue Oct 30, 2007 2:11 am
by zimanli
Greetings.
We are validating a method transferred from another company, which has been approved by FDA
they use ODS inertsil 10cm*4.6mm*3um column. the column flow is 2ml/min. is it too fast?
how is column flow related with the particle size d ID?
Thank you in advance!
Posted: Tue Oct 30, 2007 2:23 am
by Consumer Products Guy
It's OK if your pressure stays OK and doesn't overpressure.
Posted: Tue Oct 30, 2007 3:37 am
by duantech
It shall be OK. The column is kind of short.
Posted: Tue Oct 30, 2007 8:42 am
by zokitano
how is column flow related with the particle size d ID?
Flow rate is related with the column internal diameter:
Flow rate = f (diameter^2) ; f - function
e.g. if the column I.D is 4.6mm at 2mL/min flow, then the flow that should be used if you change the column with another with 2.1mm I.D is:
(4.6mm/2.1mm)^2 = 4.8 (rounded to 5)
The flow rate will be 2mL/min:5 = 0.4mL/min for the narrower column.
Regards
Posted: Wed Oct 31, 2007 1:39 am
by Uwe Neue
I have run many methods on a 4.6 x 10 x 3.5 micron column at this flow rate. For water, I expect a pressure around 3000 psi, less for mixtures of acetonitrile and water. Only for a methanol-water mixture, you are pushing the limits.