Non-porous particles in HPLC

[adam]

Does anyone have any experience with non-porous particles in HPLC. Specifically, do you know if there are problems with insufficient retention since there is less stationary phase?

Also, can you recommend any companies that specialize in non-porous HPLC packings.

Thanks!! Adam

[Koen Hollebekkers]

Hello adam,

We (Shimadzu), sell non porous columns in Europe under the name Pathfinder. These high efficient materials have as major disadvantage the low loading capacity. For this reason we do not pay to much attention to these materials.
I do not have to much experience with there retention behavior with respect to porous particles.

Good luck

[tom jupille]

Also check the Micra NPS columns from Eprogen:
http://www.eprogen.com/hplc/bonded/plat ... /index.cfm

In the "close" category is the Agilent "Poroshell" packings with a thin porous layer on an impermeable core:
http://www.chem.agilent.com/scripts/Lit ... WHID=32861

Generally these non-porous or "pellicular" packings are less retentive than more traditional porous material, but I'm not sure this is a disadvantage; it simply means you use a weaker mobile phase (bear in mind that there is a tremendous variability in surface area among the porous packings). The manufacturer has to have good control over particle size distribution (since all of the active surface is on the outside of the particle). And, as Koen Hollebekkers pointed out, this type of packing is easily overloaded.

On the plus side, efficiency for large molecules increases dramatically because they don't have to diffuse in and out of pores.

[adam]

Thank you gentlemen. Adam