Chemistry Stack Exchange is a question and answer site for scientists, academics, teachers, and students in the field of chemistry. It only takes a minute to sign up.
Sign up to join this community
I am using a smaller diameter column than my previous one keeping all other factors such as stationary phase, solvent, solvent gradient constant. (Obviously, flow rate will be less in smaller column). I would like to know will changing the diameter affect the retention time of my target?
I searched and got results like this and this But they do not mention about the effect of column diameter on retention time. Moreover, I am weak in understanding mathematical equations.
The key idea is that when you change column diameter, you keep the superficial linear velocity the same. For example if I have an analyte which elutes on a 10 cm x 4.6 mm i.d column at 7 minutes at 1 mL/min. Now we change the diameter to 3 mm, we have to use a flow rate of 0.425 mL/min to keep the retention time the same. Now we wish reduce the diameter further, say 2.1 mm i.d., now you should use 0.21 mL/min so that your analyte elutes at 7 minutes.
Search the keyword: superficial linear velocity, HPLC
