Chromatography Forum

Hello fellow Chromatographers,

I'm looking for some help improving my standard RP column packing technique. Does anyone have a reference or source to a solid guide to RP column packing?

I'm currently working on packing a 3um C18 in a 4.6 x 50mm column, but my job involves packing a variety of materials and column hardware.

My working protocol is yielding columns with tested plate counts of 5000-8000 and tailing factors of about 1.5. I would like to further reduce tailing and increase the uniformity of the packed bed.

I usually slurry the bonded silica phase with HPLC grade acetone and push with 100% HPLC grade methanol or acetonitrile (ACN seems the better of the two for this) at 8000psi for about 15 minutes. I don't make a precise measurement of the slurry density (mass of material versus volume of slurry) and maybe this is an area to improve.

I appreciate any tips or leads on a packing guide that might help me improve these columns.

Well I have a few improvements to report,

I've managed to reduce the tailing factor to about 1.3 by decreasing my slurry density and increasing the run time of the push stage.

I would still like to reduce tailing further (1.2 would be acceptable), does anyone have some advice?

HAZMAT,

Are you testing a neutral compound for tailing? Basic compound use to tail more , it would be better if you test your own target analites or neutrals then. I used to re-fill LC columns with gaps or contaminated heads with pressures of 6000 PSI (400 bar) or less, not perfect but worked.
Few people publish today on this subject, maybe this, thisor this patent can be useful.