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Posted: Fri Feb 24, 2006 7:50 pm
by alambic
I can't just switch the solvent with progressive gradient solution (like starting with 90% THF go to 70% THF and so on until I completely switch to DMF)?

Posted: Fri Feb 24, 2006 11:31 pm
by Uwe Neue
Unfortunately, PEA is correct. These polymeric packings swell and shrink during the conversion from one solvent to another. This is why there are columns available that are shipped in THF and others that are shipped in DMF. There is a real risk that the columns that you are converting yourself may not survive this procedure. Please check the C/U manual!

Posted: Mon Feb 27, 2006 12:16 pm
by alambic
and if I switch to DMAC like PEA suggested? Is it the same problem?

Posted: Mon Feb 27, 2006 4:16 pm
by alambic
Which solvents can I use with column shipped with THF because I don't want to change all the column bank...

Posted: Tue Feb 28, 2006 11:30 pm
by Uwe Neue
The THF columns can be converted to HFIP or to more non-polar solvents like methylene chloride. I do not have all relevant information here, but the C/U manual that came with the columns should have this information, including conversion protocols.

However, all things considered, if your polymer is soluble in DMF, I definitely recommend to use the DMF columns with the DMF. You may have a hard time finding a more non-polar solvent that does as good a job as the DMF does. You are going into the wrong direction.

Posted: Wed Mar 01, 2006 1:42 pm
by alambic
Thanks to all for your collaboration, you have answered all questions.

Posted: Fri Mar 10, 2006 7:16 pm
by alambic
I'm back again with another question:

I need a second opinion on this: Could I run my THF-shipped columns with a mobile phase of 50% THF / 50% DMF because some of my latex are soluble in THF and some in DMF. I talked with a Waters technician and told me there's no problem as long as both solvents are miscible.