column for very high pressure chromatography

[lotusw]

Hello,
I currently work with a method HPLC which necessite to use a column RP C18 250*4.6mm with a flow of 2.5 ml/min and a great quantity of water (80%). Of course the pressure is high (around 4000 PSI). I don't have the choice, the method is imposed by USP. I would like to know if there are columns having its caracteristiques while having a lower pressure.
Thanks.

[Klaus I.]

Search with Google for "Chromolith Performance" from Merck KGaA.

[Sallybeetle]

What is the USP column listing, L1? If resolution factor is not an issue, then you might also try using the upper particle size limit.

[Uwe Neue]

The original column was probably a 10 micron column. You should therefore look for a 10 micron column then.

The USP also allows you to change the column length, as long as you can meet the other criteria of the assay.