Hi everyone,
I'm new here and decided to get online to glean some info from those of you with experience/expertise in buffers.

I'm trying to find a buffer for pH 9 that will neither bind Cu2+ nor Zn2+, nor be included in beta-cyclodextrin, nor be insoluble in water at 25deg C. I'm making up solutions for UV-Vis analysis to determine the kinetics of ester hydrolysis reactions.

So far almost all of the buffers I've found contain primary or secondary amines (which will interfere with Zn-binding), bind to Cu2+, or have very low water solubility. (And I'm trying to avoid HEPBS which is $291 for 25g!)

This buffer is pretty much the only thing standing between me and finishing my PhD, so I'd greatly appreciate any suggestions anyone might have! Thanks!