ideal flow rate for a 3 micron, 50 mm column using waters 26

[JoseM]

Hi

I you run a HPLC method using 1% Formc acid in water/1% AcCN to 100% AcCN with a 3 micron 50 mm column, what kind of flow rate is ideal in a waters 2695 instrument ?
Also, I do not use a column heater.

Appreciate your response

thanks

[Uwe Neue]

Depends on the column diameter, what kind of samples you run, and how much time you want to spend on the method.

Assuming that you have a 2 mm column and an analyte with a MW around 200 t0 250, you want to run at 1.5 mL/min for a 1 minute gradient, at 1 mL/min for for a 2 min gradient, 0.6 mL/min for 4 min, and 0.5 mL/min for an 8 minute gradient.

[JoseM]

I am using a ID 2.1mm column. According to your suggestion, I will have to run a 0.4 - 0.5 ml/min flow rate for a 5 min method. I hope that will not cause any back pressure issues.

thanks

[sam.pedraglio]

Especially if you heat-up your column (40-50°C will be ok), you'll not have any pressure issue.

[JoseM]

Thanks for the suggestions.

[Uwe Neue]

The values were estimates for room temperature, as you said that you do not have a column heater. Backpressure is not a problem.

[sam.pedraglio]

Excuse me JoseM. Reading Uwe's last post I saw you haven't the heater. I've lost this information in your first post.