Thank You for Your help. Unfortunately article contains information about titration of amines with acids like HCl, and I'm more interested in pH during alkanolamine solutions neutralization with CO2.

I have found some data just by looking at companies that sell the amine/ bicarbonate solutions, like Sigma. I just google, for example triethylammonium bicarbonate solution, and see what comes up, or I look for the specific reagent in a catalog.

I know this is not what you may want to do, but the info might be there, in company catalogs.