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Physical & Chemical properties

Partition coefficient

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Reference
Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
from 2019-07-11 to 2019-09-02
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.8 (Partition Coefficient - HPLC Method)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 830.7570 (Partition Coefficient, n-octanol / H2O, Estimation by Liquid Chromatography)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
HPLC method
Partition coefficient type:
octanol-water
Specific details on test material used for the study:
- Batch no.: I1900071-19158-AKM
- Purity: 99.8 % (aldimine titration)
- Expiry date: 2022-04-25
Analytical method:
high-performance liquid chromatography
Key result
Type:
log Pow
Partition coefficient:
1.106
Temp.:
30 °C
pH:
10.8
Details on results:
The determined log Pow of the test item was 1.106 ± 0.000 (95 % confidence interval). The estimated Pow was 12.764 ± 0.000 (95 % confidence interval). Based on hydrolysis information, the test item is immediately hydrolysed in an aqueous medium. Hydrolysis products are the two known compounds below:

#1 hydrolysis product:
- CAS no.: 23588-51-4
- CAS name: 4-Morpholinepropanal, a,a-dimethyl-
- IUPAC name: 2,2-dimethyl-3-(morpholin-4-yl)propanal
- Common name: Aldehyde M

#2 hydrolysis product:
- CAS: 124-09-4
- CAS name: Hexamethylenediamine
- IUPAC name: 1,6-Hexanediamine

Only the #1 hydrolysis product is detectable by HPLC-UV. Based on this, results obtained in this study presumably refer to the 2,2-dimethyl-3-(morpholin-4-yl)propanal hydrolysis product of the test item.
The logPow of the #2 hydrolysis products is 0.4 at pH 13. This value is based on a weight of evidence approach and is relevant for the unionised form of the substance. At pH of ca. 10 (the pH value of the test item solution in this study), the experimentally determined partition coefficint of the #2 hydrolysis product is reported in the registration dossier to be 0.02. At this pH value the #2 hydrolysis product is in an ionised form. These values are below the measured logPow of the parent substance in this study and are supporting the statement that Sika Hardener MH has low potential for bioaccumulation based on its partition coefficient.

Table 1. Measured and calculated data of the reference compounds

Chemical name

log Pow

Retention time [min]

log k
calculated

Repeatability
(log unit)

Deviation of calculated log Pow
(log unit)

calculated log Pow

Thiourea

-

0.55

-

0.55

0.55

0.55

0.55

0.55

Mean

0.55

CV%

0.00

2-butanone

0.3

0.76

-0.418

0.033

-

0.448

0.77

-0.398

0.481

0.76

-0.418

0.448

0.76

-0.418

0.448

0.76

-0.418

0.448

0.76

-0.418

0.448

Mean

0.76

-0.415

-

0.154

0.454

CV%

0.54

-

-

Acetanilide

1.0

0.85*

-0.263

0.048

-

0.702

0.86

-0.249

0.725

0.85

-0.263

0.702

0.85

-0.263

0.702

0.84

-0.278

0.677

0.85

-0.263

0.702

Mean

0.85

-0.263

 

0.298

0.702

CV%

0.74

-

-

Acetophenone

1.7

1.69

0.317

0.006

-

1.650

1.69

0.317

1.650

1.69

0.317

1.650

1.69

0.317

1.650

1.68

0.313

1.644

1.69

0.317

1.650

Mean

1.69

0.316

 

0.051

1.649

CV%

0.24

-

-

Methyl Benzoate

2.1

3.08

0.663

0.003

 

2.216

3.08

0.663

2.216

3.08

0.663

2.216

3.08

0.663

2.216

3.08

0.663

2.216

3.07

0.661

2.213

Mean

3.08

0.663

 

0.116

2.216

CV%

0.13

-

-

Ethyl Benzoate

2.6

6.17

1.009

0.000

-

2.782

6.16

1.009

2.782

6.17

1.009

2.782

6.17

1.009

2.782

6.17

1.009

2.782

6.17

1.009

2.782

Mean

6.17

1.009

 

0.182

2.782

CV%

0.07

-

-

Benzophenone

3.2

10.98

1.278

0.003

-

3.222

10.97

1.278

3.222

11.00

1.279

3.224

11.01

1.279

3.224

11.01

1.279

3.224

11.02

1.280

3.225

Mean

11.00

1.279

 

0.024

3.224

CV%

0.18

-

-

Naphthalene

3.6

15.33

1.429

0.005

-

3.469

15.38

1.431

3.472

15.42

1.432

3.474

15.42

1.432

3.474

15.43

1.432

3.474

15.43

1.432

3.474

Mean

15.40

1.431

 

0.127

3.473

CV%

0.26

-

-

*Reinjection, because of instrument failure (pressure fluctuation)

 

Table 2.: Measured and calculated data of the test item

Test Item name

Retention time (min)

log k

log Pow

Pow

Repeatability log unit

Calculated

Test item

1.08

-0.016

1.106

12.764

0.000

1.08

-0.016

1.106

12.764

1.08

-0.016

1.106

12.764

1.08

-0.016

1.106

12.764

1.08

-0.016

1.106

12.764

1.08

-0.016

1.106

12.764

Mean

1.08

-0.016

1.106

12.764

-

Confidence interval (95 %)

0.0

-

0.000

0.000

-

CV%

0.0

-

-

-

-

 

Conclusions:
The log Pow of the test item was determined to be 1.106 ± 0.000 (95 % confidence interval). The estimated Pow was 12.764 ± 0.000 (95 % confidence interval).
Executive summary:

A study was conducted in accordance with OECD TG 117 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the HPLC method. A solution of the test substance was prepared in the mobile phase - 100 µg/mL. After equilibration of the HPLC system, the reference compound solutions and the test item solution were injected in two replicates and the procedure was repeated three times, hence, a total of 6 injections were made for each solution. Retention times tR were measured and averaged and the decimal logarithms of the capacity factors k were calculated. The log Pow of the test item was determined to be 1.106 ± 0.000 (95 % confidence interval). The estimated Pow was 12.764 ± 0.000 (95 % confidence interval). The measured logPow value under the test conditions is based on the #1 hydrolysis product, as #2 hydrolysis product could not be determined analytically. The logpow of #2 hydrolysis product was reported in the registration dossier to be 0.4 at pH13 for the unionised form and 0.02 at pH 10.3 for the ionised form. Both values support the measured logPow of Sika Hardener MH.

Description of key information

The log Pow of the test item was determined to be 1.106 ± 0.000 (95 % confidence interval) in a OECD 117 study. The estimated Pow was 12.764 ± 0.000 (95 % confidence interval).

Key value for chemical safety assessment

Log Kow (Log Pow):
1.106
at the temperature of:
30 °C

Additional information

A study was conducted in accordance with OECD TG 117 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the HPLC method. A solution of the test substance was prepared in the mobile phase - 100 µg/mL. After equilibration of the HPLC system, the reference compound solutions and the test item solution were injected in two replicates and the procedure was repeated three times, hence, a total of 6 injections were made for each solution. Retention times tR were measured and averaged and the decimal logarithms of the capacity factors k were calculated. The log Pow of the test item was determined to be 1.106 ± 0.000 (95 % confidence interval). The estimated Pow was 12.764 ± 0.000 (95 % confidence interval). The measured logPow value under the test conditions is based on the #1 hydrolysis product, as #2 hydrolysis product could not be determined analytically. The logpow of #2 hydrolysis product was reported in the registration dossier to be 0.4 at pH13 for the unionised form and 0.02 at pH 10.3 for the ionised form. Both values support the measured logPow of Sika Hardener MH.