4,4'-cyclohexylidenedi-o-cresol

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 April 2001

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:

30 March 1989

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Version / remarks:

December 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

Type:

log Pow

Partition coefficient:

3.1

Temp.:

25 °C

Remarks on result:

other: pH of the test solution was not given in the test report.

Details on results:

The log Pow of the test material was calculated using a regression curve (log k' vs. log Pow) and was found to be 3.1.

Please see the attached figures for typical chromatograms of the reference mixture and the sample solution. As can be seen, the chromatography of the test material resulted in 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. Based on the chromatographic data, the test material was considered to be stable during the test procedure.

The retention times of the individual measurements of the reference items, the test material and for the determination of the dead time are given in the Table 'Retention times in minutes of the reference items and of the test material'. The mean retention times and the derived capacity factors are stated in the Table 'Determination of the n-octanol/water partition coefficient of the test material'. Using the corresponding log Pow values of the reference items from the OECD guideline, the regression coefficients were calculated as stated in the Table 'Determination of the n-octanol/water partition coefficient of the test material'. The log Pow value of the test material was calculated from the calibration equation. The partition coefficient curve is included in the attached figures.

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

Retention time in minutes of the reference items and of the test material

	Run 1	Run 2	Run 3	Run 4	Run 5	Run 6
Thiourea (dead-time)	1.43	1.43
Benzonitrile	3.17	3.17	3.17	3.17	3.17	3.18
Benzene	4.51	4.51	4.51	4.51	4.51	4.52
Ethyl benzoate	5.11	5.11	5.11	5.10	5.10	5.11
Bromobenzene	6.55	6.54	6.54	6.54	6.54	6.55
1,4-dichlorobenzene	8.50	8.49	8.49	8.48	8.49	8.49
Isopropylbenzene (Cumol)	10.77	10.77	10.77	10.75	10.75	10.76
Test material	7.34	7.34	7.34

 

Determination of the n-octanol/water partition coefficient of the test material

	No of analysis	Mean retention time [min]	k'	log k'	log Pow
Thiourea (dead-time)	2	1.43	-	-	-
Benzonitrile	6	3.17	1.21	0.08	1.6
Benzene	6	4.51	2.15	0.33	2.1
Ethyl benzoate	6	5.11	2.56	0.41	2.6
Bromobenzene	6	6.54	3.56	0.55	3.0
1,4-dichlorobenzene	6	8.49	4.92	0.69	3.4
Isopropylbenzene (Cumol)	6	10.76	6.50	0.81	3.7
Test material	3	7.34	4.12	0.61	3.1
Linear regression slope = y-axis intercept = coefficient of regression =					0.328 -0.417 0.984

Conclusions:

Under the conditions of the study, using the HPLC method, the log Pow of the test material was determined to be 3.1 at 25°C.

Executive summary:

The partition coefficient of the test material was investigated in accordance with the standardised guidelines OECD 117 and EU Method A.8 under GLP conditions using the HPLC method.

The n-octanol/water partition coefficient was determined from the test material elution time on a reversed-phase column with UV-VIS detector in comparison with the elution behaviour of 6 reference items.

The log Pow of the test material was determined to be 3.1 at 25 °C.

Description of key information

The log Pow was determined to be 3.1 at 25 °C.

Key value for chemical safety assessment

Log Kow (Log Pow):

3.1

at the temperature of:

25 °C

Additional information

The partition coefficient of the test material was investigated in accordance with the standardised guidelines OECD 117 and EU Method A.8 under GLP conditions using the HPLC method. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

The n-octanol/water partition coefficient was determined from the test material elution time on a reversed-phase column with UV-VIS detector in comparison with the elution behaviour of 6 reference items.

The log Pow of the test material was determined to be 3.1 at 25 °C.