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Cleaning buffers from columns
Posted: Fri Jun 02, 2006 3:07 pm
by wanda50
Several years ago, ok maybe 10+, John Dolan wrote an article on the hows and whys of cleaning a column that had buffer in it. I have folks here stare at me like a deer in headlights when I tell them not to put straight water in the column. I have lost the copy I had. Can someone give me the reference or a copy?
thanks.
Posted: Fri Jun 02, 2006 6:23 pm
by Koen Hollebekkers
Hello Wanda,
Much is written about this phenomenon the last decade. I don't I have a link or a copy of the Dolan article, but I have here a link to a column written by Ron Majors.
It principally describes the same. Good luck with your colleagues!
http://www.lcgcmag.com/lcgc/data/articl ... rticle.pdf
Posted: Fri Jun 02, 2006 6:24 pm
by tom jupille
Buffer problems are a frequent topic of John's columns (probably reflecting the fact that they are ubiquitous in the lab!).
The two that come closest to your description are:
LC-GC, 7(7), 556-560 (1989) and
LC-GC, 10(11), 842-848 (1992)
I don't think LC-GCs on-line issues go back that far; if you can't find a hard copy, e-mail me privately and I can send you pdf versions.
Posted: Sat Jun 03, 2006 9:50 pm
by Victor
The essence of John Dolan's argument was that if you are using say 25% ACN/phosphate buffer, then wash it in 25% ACN/water. This is a convenient method. However, there is nothing at all wrong with washing the column in water, and I prefer it because I have a feeling that since phosphate is more soluble in water than ACN/water it will remove traces of beffer more efficiently from the system-probably I'm thinking of the pump as well as the column. BUT-if you do this you have to realize that the column then has to be re-wetted using a relatively high proportion of ACN. I do not know the exact figures (probably no-one ever studied this) but 50% ACN-water certainly works to wet the phase again. Then you can go back to using it with low ACN concnetrations without any problem at all. In fact if you are washing the column to store it at the end of the day, it is no more difficult to do it this way than the Dolan method. In the example above for instance I would not want to store the column in 25% ACN for a long period, so I would then after washing have to fill it with the storage solvent (e.g. 50% ACN; or 100% ACN for long term storage). If you wash it with water, you can then go straight to the required storage solvent.