If I concentrate a bicarbonate buffer system by removing free water from a solution (using hydrophobic hollow fiber membranes), does that change the pH?
I use the Henderson-Hasselbalch equation:
pH = pK + log ([NaHCO3]/[CO2]). If only free water removed, the two concentrations (NaHCO3 and CO2) increase equally resulting in no change in pH. That is my guess. What do you think? The buffer system I am using is 25mM NaHCO3, 135mM NaCl.