4,4'-methylenebis[N-sec-butylaniline]

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 23 May 2018 to 06 August 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: EU method A.24 (Partition coefficient (n-octanol / water), HPLC method)

Version / remarks:

2016

Deviations:

no

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:

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

Version / remarks:

1996

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

5.4

Temp.:

20 °C

pH:

9

Remarks on result:

other: Peak area of 99%

Details on results:

- Retention times of reference items used for calibration: see table below;
- Details of fitted regression line: log k' = 0.312 log Pow – 0.937 (r = 0.98, n= 16);
- Ression line: see illustration below;
- The chromatogram of test item showed one major peak (99%) and two small peaks (<1%).
- The log Pow for the major peak was reported as the log Pow of the substance.
- Average retention data for the test item: see table below;
- The value of log Pow obtained from duplicate measurements was within ± 0.1 log units.

Table: Results Partition coefficient n-octanol-water (HPLC method)

Substance	Retention time (min)			log Pow	Pow	Peak area (%)
	RT1	RT2	mean
Formamide (t0)	0.578	0.578	0.578
Benzylalcohol	0.700	0.681	0.691	1.1
Nitrobenzene	0.830	0.792	0.811	1.9
Toluene	1.263	1.161	1.212	2.7
1,4-Dichlorobenzene	1.590	1.407	1.499	3.4
Biphenyl	2.044	1.742	1.893	4.0
Dibenzyl	3.106	2.529	2.818	4.8
Triphenylamine	5.144	4.020	4.582	5.7
4,4’-DDT	7.186	5.501	6.344	6.5
Test item – peak 1	1.664	1.654	1.659	3.9	7.5E3	0.20
Test item – peak 2	3.803	3.711	3.757	5.4	2.4E5	99
Test item – peak 3	5.585	5.374	5.480	6.0	9.5E5	0.63

Conclusions:

The log Pow of the substance at pH 9 and ca. 20°C was determined to be 5.4. Pow= 2.4E5.
The log Pow at pH 9 and ca. 20°C for the impurities was determined to be 3.9 and 6.0. Pow= 7.5E3 and 9.5E5, resp.

Executive summary:

The partition coefficient (n-octanol/water) of the substance was determined using the HPLC method. The study was performed in accordance with EC A.24, OECD 117 and OPPTS 830.7570 and in compliance with GLP. Formamide was used as unretained substance. For the construction of the regression line, eight references substances (log Pow range according to OECD TG 117: 1.1 to 6.5 at ca. 20°C) were used. Duplicate injections of unretained substance, reference substances and test item in an UPLC-UV system. Based on pKa, the study was performed at pH 9. The mobile phase was 75/25 (v/v) methanol/buffer pH 9 and the wavelength of detection was 210 nm. Each chromatogram of the substance showed one major peak (99%) and two small peaks (< 1%). Substituting the mean retention times in the regression line yielded log Pow values of 5.4 for the substance (major peak), and 3 .9 and 6.0 for the impurities. Pow= 2.4E5 (substance), 7.5E3 and 9.5E5 (impurities).

Description of key information

Log Pow at 20°C: 5.4 (EC A.24, OECD 117, OPPTS 830.7570: HPLC method)

Key value for chemical safety assessment

Log Kow (Log Pow):

5.4

at the temperature of:

20 °C

Additional information

The study was performed at pH 9. The mobile phase was 75/25 (v/v) methanol/buffer pH 9 and the wavelength of detection was 210 nm. Each chromatogram of the substance showed one major peak (99%) and two small peaks (< 1%). log Pow (major peak): 5.4; log Pow (impurities): 3.9 and 6.0.