Does any one have articles that indicate the appropriate flushing solvents for HPLC Columns?
A menber of my staff was discovered to be flushing a Silica Column with Methanol after having used a Chloroform : Acetic Acid 95 : 5 mobile phase. When challenged I was informed that this was the way it had always been done.
Kevin Dawson
Pharmacy QA Laboratory Manager
St. Thomas' Hospital ,
London
SE1 7EH
Tel +44 (0)20 7928 9292 extn 3001
Fax +44 (0)20 7960 5651
E-Mail kevin.dawson@gstt.sthames.nhs.co.uk

Silica columns can be flushed with methanol, and even with water. As a matter of fact, I recommend the flushing of silica columns with both solvents if the column is contaminated. One can even use silica columns in an aqueous environment as either HILIC columns or ion-exchangers. I do not know where the rumors come from that tell you not to do this kind of stuff. If silica would not be stable in water, we would not have any sand on our beaches....

Apparently, the apprehension to use water or alcohols on silica columns comes from the very early columns. In around 1970 (CU, Boulder) we proudly used the first commercial (to our knowledge) high performance column in an adaptation from a TLC separation. Carefully following instructions, we diligently eliminated any possible sources of -OH in the sample, etc. The mobile phase was a high grade of chloroform, nevertheless, the column was shot prior the first injection, as we later found out. We had forgotten that the chloroform was stabilized with ethanol. We just barely managed to convince our advisor to get a new one, which worked fine with chloroform that we cleaned up with con. sulfuric acid.


Regarding modern columns: some manufacturers have excellent instructions for flushing their columns.
The above tabu is of the past.

Most new columns probably have washing and storage instructions included when shipped--at least the ones we buy do. Manufacturers may have instructions in their catalogs (saw one today), and if all else fails, call them!

I'd follow their recommendations unless I had a good reason not to. Saves explanations.