Registration Dossier

Administrative data

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

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 112 (Dissociation Constants in Water)
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Remarks:
lumps of various sizes

Results and discussion

Dissociating properties:
yes
Dissociation constant
pKa:
8.7
Temp.:
20 °C

Any other information on results incl. tables

Result

pKa = 8.7

Estimated accuracy: ± 0.1

Note:

Only the dissociation constant of the test item (main component) was determined. A strong base was also detected at the first inflection point (EP1).

Step

Volumne of titrant

[ml]

1.    Determination

 

2.    Determination

 

3.    Determination

 

 

 

pH

pKa

pH

pKa

pH

pKa

0

1.80

8.64

8.44

8.65

8.46

8.67

8.46

1

1.90

8.62

8.45

8.62

8.46

8.63

8.47

2

2.00

8.59

8.47

8.59

8.48

8.61

8.48

3

2.10

8.68

8.59

8.70

8.62

8.71

8.62

4

2.20

8.65

8.60

8.66

8.62

8.68

8.63

5

2.30

8.63

8.62

8.64

8.64

8.66

8.64

6

2.40

8.69

8.72

8.71

8.74

8.72

8.74

7

2.50

8.67

8.73

8.68

8.76

8.70

8.76

8

2.60

8.65

8.76

8.66

8.77

8.67

8.77

9

2.70

8.65

8.79

8.71

8.86

8.73

8.87

10

2.80

8.65

8.82

8.69

8.87

8.71

8.88

 

mean of pKa values

8.66

8.68

8.69

standard deviation

0.13

0.14

0.14

pKa (overall average)

8.7 +/- 0.1

Applicant's summary and conclusion