1,6-Hexanediamine, N1,N6-bis[2,2-dimethyl-3-(4-morpholinyl)propylidene]-

Partition coefficient

Link to relevant study record(s)

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

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - HPLC Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7570 (Partition Coefficient, n-octanol / H2O, Estimation by Liquid Chromatography)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

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:

10.18

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.