soma - 18-11-2016 at 02:50
I've seen several methods: slurry; dry pack - adding adsorbent 1st , then eluant - or adding eluant 1st, then adsorbent.
Any preferences?
phlogiston - 18-11-2016 at 04:16
What kind of column? Are we talking HPLC columns with micron-sized particles? nano-LC? Or mm - cm diameter columns with large particle sizes?
I assume the latter, because I think you would have been more specific otherwise.
I prefer packing it as a slurry in the mobile phase you want to use, because some column materials expand or contract when they are wetted or
equilibrated. This can result in bubbles or cracks in your stationary phase and cause excessive peak broadening.
If the column needs to be kept cold during the separation, make sure to cool everything down well before packing the column, eg. overnight in the cold
room. Then make sure it never warms up, not even briefly. Otherwise, you may have bubbles form in the column due to gasses that were dissolved in the
equilibration buffer.
[Edited on 18-11-2016 by phlogiston]
[Edited on 18-11-2016 by phlogiston]
laserlisa - 18-11-2016 at 05:09
Wet packing (slurry) all the way!
Metacelsus - 18-11-2016 at 05:38
Yep, slurry is definitely best.
Fulmen - 18-11-2016 at 07:12
I have only added slurry to the mobile phase. The other methods might work, but I've never experienced problems with the wet method.
Maroboduus - 18-11-2016 at 09:03
Heat generation can also be a problem pouring solvent into some dry packed columns.
This can also contribute to the problems mentioned above.
soma - 12-1-2017 at 02:23
Thanks for the responses.
Another question.
Would there be a problem in preparing the column and leaving it for many hours before using it? (Keeping a layer of solvent above the silica).
alking - 12-1-2017 at 11:42
I pack columns with a slurry, packing dry is always a bad idea imo. I do pack smaller burettes dry however.
Scalebar - 13-1-2017 at 04:43
For our size exclusion columns it's wet pack from slurry using a reservoir on the top, if you want to show off you can start messing with ramping the
pressure to control the shape of the peak as it elutes ( but it is way too much effort ). We keep packed columns for years - as long as they never run
dry.