Neff

[koen_shimadzu]

Can someone explain me why to use the effective plate number. As I understood it is coming flow cap GC. Peaks close to the dead volume have much higher plate numbers than later eluting peaks. But what is causing this effect and how can we relate this to LC?

[tom jupille]

Can someone explain me why to use the effective plate number

Off the top of my head, I can't think of one in LC.

[Uwe Neue]

I never understood the value of measuring effective plate numbers. As a matter of fact, they may give you very misleading results. Say you have two columns with the same standard plate count, but one column with a low retention factor, and another column with a high retention factor. The one with the low retention factor will give you a low "effective plate count", but if you adjust the mobile phase compostion by a few percent, such that the retention on both columns is the same, the effective plate count of both columns is the same.

The fact that one column is less retentive than the other, this is something that I can learn from the retention factors. That there is no difference in the performance of both columns, I can learn this from the plate count.

[koen_shimadzu]

Hmm, it appears that I was not the only one that was confused. I’ll stick to the k’ value and plate count.