van deemter

[olivia]

Hi can anyone tell me the factors affecting mass transfer in the stationary and mobile phases.
I think the viscosity of the mobile phase, the temperature of the separation, which both affect the diffusivity of the analyte in the mobile phase.
I read somewhere the "thickness of the stationary phase"-what is the "thickness" referring to? Is it the bonded layer?
Are there other factors I have missed
Thanks
Liv

[DR]

Thickness of the stationary phase is for GC applications using a glass column with a coating of stationary phase on it. The coating thickness has an impact on diffusion.

Probably the most important thing to consider is the partition coefficient for each analyte between the mobile and stationary phases in use. If it were not for each analyte having a different partition coefficient under whatever run conditions you use, you would have no separation.