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Physical & Chemical properties

Dissociation constant

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Administrative data

Endpoint:
dissociation constant
Type of information:
experimental study
Adequacy of study:
key study
Study period:
19 July 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
other: EC A.25 (Dissociation Constants in Water)
Version / remarks:
2017
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 112 (Dissociation Constants in Water)
Version / remarks:
1981
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 830.7370 (Dissociation constants in water)
Version / remarks:
1996
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
white powder
Specific details on test material used for the study:
Water solubility: 574 g/L at 20°C

Results and discussion

Dissociating properties:
yes
Dissociation constant
No.:
#1
pKa:
1.66
Temp.:
20 °C
Remarks on result:
other: calculated from structure

Any other information on results incl. tables

When using the titration method, a pKa value for the test item could not be determined due to lack of indication for an equivalence point. No pKa values could be determined from the titration curves obtained. The result of the Perrin calculation method was therefore reported as dissociation constant of the substance.

Applicant's summary and conclusion

Conclusions:
The substance has a pKa value of 1.66.
Executive summary:

Using the Perrin calculation method (pKalc 5.0, module in Pallas 3.0, CompuDrug International, USA) a pKa of 1.66 was calculated for the basic group in the structure of the substance. There are no acidic groups in the structure. Performance of the titration method (EC A.25, OECD 112, OPPTS 830.7370) did not result in an experimentally determined pKa valuedue to lack of indication for an equivalence point. The calculated pKa value of 1.66 was therefore reported as dissociation constant of the substance.