TAPS (buffer)

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

TAPS

Names
Preferred IUPAC name 3-{[1,3-Dihydroxy-2-(hydroxymethyl)propan-2-yl]amino}propane-1-sulfonic acid
Other names N-Tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid
Identifiers
CAS Number	29915-38-6 Y
3D model (JSmol)	Interactive image
ChemSpider	108495 N
ECHA InfoCard	100.045.398
PubChem CID	121591
UNII	Y5DC3IN066 Y
CompTox Dashboard (EPA)	DTXSID3067528
InChI InChI=1S/C7H17NO6S/c9-4-7(5-10,6-11)8-2-1-3-15(12,13)14/h8-11H,1-6H2,(H,12,13,14) N Key: YNLCVAQJIKOXER-UHFFFAOYSA-N N InChI=1/C7H17NO6S/c9-4-7(5-10,6-11)8-2-1-3-15(12,13)14/h8-11H,1-6H2,(H,12,13,14) Key: YNLCVAQJIKOXER-UHFFFAOYAP
SMILES C(CNC(CO)(CO)CO)CS(=O)(=O)O
Properties
Chemical formula	C7H17NO6S
Molar mass	243.27 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

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 pK_a value of 8.44 (ionic strength I = 0, 25 °C).^[2]

The pH (and pK_a at I ≠ 0) of the buffer solution changes with concentration and temperature, and this effect may be predicted e.g. using online calculators.^[3]