2-(N-Morpholino)ethanesulfonic acid; 4-Morpholineethanesulfonic acid;
2-morpholinoethanesulfonic acid; 2-(4-morpholino)ethanesulfonic acid;
MES; MES hydrate; morpholine-4-ethanesulfonic acid hydrate;

Technical Data

CAS Number: 4432-31-9
Molecular Formula: C6H13NO4S
Molecular Weight: 195.24
Beilstein Registry Number: 141319
EC Number: 224-632-3

FabriChem Specifications

CAS No. 4432-31-9
Molecular FormulaC6H13NO4S
Molecular Weight195.24
Assay (Titration)99.0% Min.
AppearanceWhite Powder
Solubility (10% in H2O)Clear & Complete
Moisture1.0% Max.
Pka (25°C)5.9 – 6.3
pH (10% in H2O)2.8 – 4.0
IRConform to Known Standard
UV (10% in H2O):
A 260 nm0.1 Max.
A 280 nm0.1 Max.

Molecular Structure



MES [2-(N-Morpholino)ethanesulfonic acid] is one of the known buffering agents used for biochemical and biological research. These buffering agents are now collectively referred to as “Good’s Buffers”. Good’s Buffers are important tools used in modern biological laboratories for a variety of their properties, including but not limited to being zwitterionic (aka hybrid or dipolar) compounds.