Registration Dossier
Registration Dossier
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EC number: 250-264-8 | CAS number: 30618-84-9
Dissociation constant
Administrative data
Link to relevant study record(s)
Description of key information
Key value for chemical safety assessment
- pKa at 20°C:
- 8.4
Additional information
The reaction mass of glycerol and thioglycolic acid is a complex mixture. Therefore, pKa values for individual components of the mixture were estimated by QSAR using SPARC (v. 4.5) chemical reactivity models for estimation ionization pKa in water. There are three types of ionisable groups present in the components of the reaction mass: thiol, hydroxyl and carboxyl groups. pKa values of individual components of the reaction mass are: 1,2-propanediol-3-sulfanylacetate: pKa,SH=8.40 at 20°C;
2-hydroxy-1,3-propanediyl bis(mercaptoacetate): pKa1,SH=8.07, pKa2,SH=8.68, pKa3,OH=13.78 at 20°C;
glycerol: does not dissociate in pH range -0.2 to 14 at 20°C;
1,3-propanediol-2-sulfanylacetate: pKa,SH=8.38 at 20°C;
mercaptoacetic acid: pKa1,COOH=3.76, pKa2,SH=10.04 at 20°C and
1,2,3-propanetriyl tris(mercaptoacetate): pKa1,SH=7.79, pKa2,SH=8.29, pKa3,SH=8.78 at 20°C.
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