Chromatography Forum

Could anybody tell why there is only C8 and C18 columns available. Why not something like C4 or C100 columns?

Chromforum history: viewtopic.php?f=1&t=1649&p=5329

Available modifications on the HPLC column market are:

C1, C4, C8, C18, C30 and it might be that I missed some newer and older products. Please check the USP list for column specifications like L1, L2 etc.!
A quick look into catalogues from major manufacturers will give you a good overview.

A C12 is also available from Phenomenex (Synergi Max). We have found these very effective.
(And no I don't work for them!)

GCguy

I've got a C6 column somewhere in the lab that I've used before. As you'd expect it's much like a C8 really.

from a marketing point of view C18 has become a standard and to break away from that without good reason would be difficult.

I think the differences between C8 and C18 are quite subtle in any case under most circumstances - slightly different selectivity but rarely drastically so. Most method development would probably conclude that if neither C8 nor C18 provides the appropriate selectivity, then it's time to find some other basis for selectivity rather than spend time with longer or shorter chains.

There are a lot of different HPLC columns available. Firstly you have different packing material for example aquasil, chiral, µ bondapak,delta pak, equisil, intersil, kromasil, lichrospher ect. Secondly you have different packing descriptions for example 208 MS C8. You also have different particle sizes, inner diameter, pore sizes and different lenght. Furthermore you can choose between different brands. You can have a look to the site of altmann analytik. There you can use the convenient column configurator http://www.analytics-shop.com/gb/HPLC-C ... nfigurator