Reaction products of 4,4'-methylenebis(2,6-dimethylaniline) and 4-aminobenzenesulfonic acid with 2,4,6-trichloro-1,3,5-triazine, diazotised and subsequently coupled with N-(2-methoxyphenyl)-3-oxobutanamide

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 October 2006 and 20 November 2006

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)

Version / remarks:

2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

2.7

Temp.:

25 °C

pH:

6.6

Details on results:

During the preliminary test, the log Pow of the test material was estimated to be above 1.3. Thus having the free choice between both methods, the HPLC method was chosen to conduct the main test. Six common standards which have known log Pow values in the range of 1.1 to 3.0 were used as reference standards during the main test.
The test material solution was injected three times and the combined reference solution was injected six times. The thiourea solution was injected twice. The log Pow was calculated using a regression curve (log k’ vs log Pow) and was found to be 2.7.
The chromatography of the test material showed one main peak with a well-defined and reproducible retention time. The HPLC method was therefore considered to be suitable for the purpose of the study.
Under the conditions of the study the n-octanol/water partition coefficient of the test material was determined to be log Pow = 2.7 using the HPLC method.

Retention Time in Minutes of the Reference and Test Materials

Substance	1^strun	2^ndrun	3^rdrun	4^thrun	5^thrun	6^thrun
Thiourea (dead time)	1.183	1.172
Benzyl alcohol	2.341	2.341	2.340	2.342	2.330	2.347
Benzonitrile	2.977	2.990	2.976	2.982	2.971	2.992
Nitrobenzene	4.185	4.193	4.184	4.189	4.185	4.215
Anisole	6.062	6.055	6.058	6.069	6.075	6.114
Ethyl benzoate	11.269	11.204	11.250	11.284	11.349	11.408
Bromobenzene	15.528	15.392	15.472	15.524	15.649	15.680
Test material	11.071	11.083	11.146

 

Results of Linear Regression of Log k’ vs Log Pow

Substance	Number of analysis	Mean retention time [min]	k’	Log k’	Log Pow
Thiourea (dead time)	2	1.18	-	-	-
Benzyl alcohol	6	2.34	0.99	-0.01	1.1
Benzonitrile	6	2.98	1.53	0.19	1.6
Nitrobenzene	6	4.19	2.56	0.41	1.9
Anisole	6	6.07	4.16	0.62	2.1
Ethyl benzoate	6	11.29	8.59	0.93	2.9
Bromobenzene	6	15.54	12.20	1.09	3.0
Linear regression	slope				0.616
	y-axis intercept				-0.724
	coefficient of regression				0.991

 

Results of Test Material Analysis

Number of analysis	Retention time [min]	k’	Log k’	Log Pow	Mean Log Pow
1	11.07	8.40	0.92439	2.7	2.7
2	11.08	8.41	0.92492	2.7
3	11.15	8.47	0.92767	2.7

The tabulated values represent rounded results which were obtained by calculation using the exact raw data.

Conclusions:

Under the conditions of the study the n-octanol/water partition coefficient of the test material was determined to be log Pow = 2.7.

Executive summary:

The n-octanol water partition coefficient of the test material was assessed according to OECD Test Guidelines117 and EU Method A.8. using the HPLC method and in compliance with GLP.

During the preliminary test, the log Pow of the test material was estimated to be above 1.3.  Thus having the free choice between both methods, the HPLC method was chosen to conduct the main test.  Six common standards which have known log Pow values in the range of 1.1 to 3.0 were used as reference standards during the main test.

The test material solution was injected three times and the combined reference solution was injected six times.  The thiourea solution was injected twice.  The log Pow was calculated using a regression curve (log k’ vs log Pow) and was found to be 2.7.

The chromatography of the test material showed one main peak with a well-defined and reproducible retention time.  The HPLC method was therefore considered to be suitable for the purpose of the study.

Under the conditions of the study the n-octanol/water partition coefficient of the test material was determined to be log Pow = 2.7 using the HPLC method.

Description of key information

Under the conditions of the study the n-octanol/water partition coefficient of the test material was determined to be log Pow = 2.7.

Key value for chemical safety assessment

Log Kow (Log Pow):

2.7

at the temperature of:

25 °C

Additional information

The n-octanol water partition coefficient of the test material was assessed according to OECD Test Guidelines117 and EU Method A.8. using the HPLC method and in compliance with GLP. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

During the preliminary test, the log Pow of the test material was estimated to be above 1.3.  Thus having the free choice between both methods, the HPLC method was chosen to conduct the main test.  Six common standards which have known log Pow values in the range of 1.1 to 3.0 were used as reference standards during the main test.

The test material solution was injected three times and the combined reference solution was injected six times.  The thiourea solution was injected twice.  The log Pow was calculated using a regression curve (log k’ vs log Pow) and was found to be 2.7.

The chromatography of the test material showed one main peak with a well-defined and reproducible retention time.  The HPLC method was therefore considered to be suitable for the purpose of the study.

Under the conditions of the study the n-octanol/water partition coefficient of the test material was determined to be log Pow = 2.7 using the HPLC method.