Effect of Tetrabutyl ammonium on Columns

[adam]

Hello

I remember reading a long time ago that things like tetrabutyl ammonium will damage columns over time.

What I am trying to recall is: does it hydrolyze the bond between the ligand and the silica or does it degrade the silica itself.

Does anyone know. This will drive the decision of what column we purchase.

(by the way, the application we are running right now is at neutral pH. We're doing thiosulfate by ion pairing)

Much Thanks
Mark

[tom jupille]

I believe the argument is that cationic IP reagents stick tightly to ionized silanols. See this thread:
viewtopic.php?f=1&t=6325&p=28524
and the last few posts in this thread:
viewtopic.php?f=1&t=2510&p=9575

[adam]

Hmm. Well for this application we need something that resists hydrolytic cleavage of the ligands.

I'm currently deciding between Waters Xbridge and Agilent Zorbax.

I know that XBridge is supposed to be very resistant in terms of the particle degrading. But I'm not sure if it is as good as Zorbax with respect to resisting hydrolysis of the ligands.

Does anyone know.

Thanks

[tom jupille]

Cleavage of bonded phase is likely to be more of a problem at low pH. Columns tend to be optimized for either low pH operation (e.g., the Zorbax StableBond) or high pH (e.g. the Waters Acquity).

With regard to the Zorbax columns, they are not all "StableBond" with the "sterically protected" bond.