TAPS ([tris(hydroxymethyl)methylamino]propanesulfonic acid) is a chemical compound commonly used to make buffer solutions.

It can bind divalent cations, including Co(II) and Ni(II).

[1] 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]