Registration Dossier

Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
from 23 April 2018 to 01 June 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
other: EU method A.24 (Partition coefficient (n-octanol / water), HPLC method)
Version / remarks:
2016
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
Version / remarks:
2004
Deviations:
no
Qualifier:
according to
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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Details on test material:
Appearance: Clear colourless to pale yellow liquid
Storage: In refrigerator (2-8°C)

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficientopen allclose all
Key result
Type:
log Pow
Partition coefficient:
1.7
Temp.:
20 °C
Remarks on result:
other: Result for the peak with area of 98%. Unbuffered mobile phase.
Key result
Type:
log Pow
Partition coefficient:
1.8
Temp.:
20 °C
Remarks on result:
other: Result for the peak with area of 1.9%. Unbuffered mobile phase.
Details on results:
- Retention times of reference substances used for calibration: see table below;
- Details of fitted regression line: log k' = 0.625 x log Pow – 0.45 (r = 0.998, n= 12);
- Chromatograms and graph of regression line attached;
- The UPLC chromatogram of the test item showed one major peak (98%) and one small peak (1.9%).
- 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.

Any other information on results incl. tables

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

Substance

Retention time (min)

log Pow

Pow

Peak area
(%)

RT1

RT2

mean

Formamide (t0)

0.623

0.626

0.625

 

 

 

2-Butanone

0.944

0.945

 

0.3

 

 

Benzylalcohol

1.834

1.837

 

1.1

 

 

Nitrobenzene

3.716

3.718

 

1.9

 

 

Toluene

12.221

12.224

 

2.7

 

 

Bromobenzene

16.013

16.025

 

3.0

 

 

1,4-Dichlorobenzene

30.467

30.469

 

3.4

 

 

Test item – major component

3.295

3.299

3.297

1.7

54

98

Test item – minor component

3.514

3.518

3.516

1.8

62

1.9

Remark: the log Pow values of the reference substances are as mentioned in OECD TG 117.

Applicant's summary and conclusion

Conclusions:
The log Pow of the substance at neutral pH and 20°C was determined to be 1.7 (Pow = 54).


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.8, OECD 117 and OPPTS 830.7570 and in compliance with GLP.

Formamide was used as unretained substance. For the construction of the regression line, 6 references substances with known log Pow values (at 20°C) ranging from 0.3 to 3.4 were used.

Duplicate injections of unretained substance, reference substances and test item were made on an UPLC-UV (210 nm) system. The mobile phase was 40/60 (v/v) methanol/water. Each chromatogram of the test item showed one large (98%) and a small substance peak (1.9%).

The log Pow values for the two peaks were calculated from the regression line to be 1.7 and 1.8, resp. It is assumed that the peak at 98% is from the main constituent of the substance.

The log Pow of the substance at neutral pH and 20°C was therefore concluded to be 1.7 (Pow = 54).