TAPS is effective to make buffer solutions in the pH range 7.7–9.1, since it has a pKa value of 8.44 (ionic strength I = 0, 25 °C).[2]
The pH (and pKa at I ≠ 0) of the buffer solution changes with concentration and temperature, and this effect may be predicted e.g. using online calculators.[3]
References
^Machado, Carina M. M.; Gameiro, Paula; Soares, Helena M. V. M. (2008). "Complexation of M–(buffer)x–(OH)y systems involving divalent ions (cobalt or nickel) and zwitterionic biological buffers (AMPSO, DIPSO, TAPS and TAPSO) in aqueous solution". J. Solution Chem.37 (5): 603–617. doi:10.1007/s10953-008-9265-3. S2CID97906177.