Chromatography Forum

Can anyone suggest a HPLC column for general use of small molecules?

5 micron Symmetry C18, 4.6 x 150 mm.

Unison UK-C18 (3um). It can be used in 100% aq. eluent - and is a great column for screening.

The link below explains the benefits of 3um vs. 5um:
http://www.imtaktusa.com/site_media/fil ... TI015E.pdf

Outside of any particular brands, any sort of C18 is a good general purpose choice. I would opt for a 3.5 um 150x4.6mm column, personally. Please see mac-mod.com's (http://mac-mod.com/ace.html) "Comparison Guide to C-18 Reversed Phase Columns" for a little guidance on which C18 might be good for your particular application, then contact the various manufacturers of the closest columns that may fit your needs to see which of those columns might actually be right for what you're looking for.

All the manufacturers sell a range of reasonable C18 columns nowadays, and if you're buying a column without knowing exactly what it will be used for, you could probably pick any.

But think about the cleanliness of your samples and whether you want to run edgy, difficult solvents (near to the pH limits, hot temperatures); do you change guard columns often, and how much cash do you have? Price of guard columns can be an important consideration if you routinely handle dubious samples, and the price/convenience of guard columns does vary. A really expensive beautiful column that's got half-clogged with bad sample may not perform as well as a medium-quality C18 that's had its guard changed regularly.

+1

A C18 column is a good choice in you don't exactly know which compound you want to analyse

Thanks all for the suggestions!

Hi,
If you have a good LC with low dead volume (even of not "UPLC") then I would rather suggest to start with a modern column like Phenomenex Kinetek 2.6 µm 2.1 mm X 50 mm. Saves time and mobile phase. There are also other similar.
(Bad old LCs, no name an model mentioned, are used with 4.6 mm diameter and 5 µm particles)