Chromatography Forum

If you look at the Amide application note book you will see that when they use 0.2% TEA in the mobile phase they run at 35C. When they run at high tem they run at much lower concentration of TEA... I always suspected that was because of column life issues at h igh temp at high pH

I suspect that is what is happening with your columns

Jamie,

You have two concerns here to be worried about:

1) Effect of NH4OH on the column material vs. the effect of TEA. Presumably you will be in a position to report on that soon.

2) Reaction of the additive with your analytes. TEA is a tertiary amine and so cannot form a Schiff base. The ammonium ion in NH4OH may well form them with your reducing sugars. That's why nobody uses it to increase the pH (and thus increase the rate of mutarotation).