Chromatography Forum

When Calculating Column Volume, do you use the Settled Bed Height for the height or do you use the packed Height for your height in the volume equation.

Im picking up an abandoned chrom process (it just so happens that i have no chrom experience) It turns out that our process has been run in the past using the settled Bed Height on TMAE and Q-sepharose Fast Flow columns, but there has been some speculation if this is the right way to calculate the CV.

It's been a loong time since I worked with non-HPLC systems. What's the difference between "settled bed height" and "packed bed height"?

In principle, you should use the height of the bed under the conditions you are running.

It's been a loong time since I worked with non-HPLC systems. What's the difference between "settled bed height" and "packed bed height"?

In principle, you should use the height of the bed under the conditions you are running.

Settled- you pour the Resin, and let it settle for a few hours or overnight

Packed- when you start flow packing it with a buffer- the resin starts to compress.

Weird, one would think that only the bed volume under running conditions would have any relevance.

As HW indicated, it's the packed volume that matters.