By Bruce Girton on Tuesday, August 3, 2004 - 03:21 pm:

If anyone could offer any insights on the most efficient way to wash tetrabutylammonium out of a C18 column, I would appreciate it.

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By A.Mouse on Tuesday, August 3, 2004 - 06:47 pm:

This appears to be a very difficult task, not worth the solution. Column manufacturers recommend not to do anything, and just to buy a new column.
I can not guarantee any results, because until now I listened to the advice I got. But here is some thinking:
Go to an acidic mobile phase, maybe with TFA or formaic acid. This should neutralize the silanols. Then go to a high organic concentration (at the same concentration of acid that you are using). Maybe 80% organic is OK, Now wash the column for a while.

How will you know that you got rid of the TBA? MS?

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By Jimmy on Sunday, August 15, 2004 - 08:14 pm:

I would use 0.1% TFA, 70% methanol and 30% ammonium phosphate buffer, 25 mM, pH 2.5. Do check solubility before washing.