Registration Dossier

Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
from 15 March 2018 to 18 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
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

Test material

Constituent 1
Reference substance name:
Extract obtained from the shell of Theobroma cacao (Malvaceae) by co-extraction with ethanol and propylene glycol
EC Number:
948-055-8
Molecular formula:
not applicable as it is a UVCB
IUPAC Name:
Extract obtained from the shell of Theobroma cacao (Malvaceae) by co-extraction with ethanol and propylene glycol
Test material form:
liquid: viscous
Details on test material:
- Physical appearance: dark brown to black viscous liquid
- Storage conditions: in refrigerator (2-8°C) protected from light

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficientopen allclose all
Key result
Type:
log Pow
Temp.:
20 °C
pH:
7
Remarks on result:
other: The log Pow and Pow values of this peak (70% area) could not be calculated because tr < tr of formamide.
Key result
Type:
log Pow
Partition coefficient:
-0.2
Temp.:
20 °C
pH:
7
Remarks on result:
other: Mean RT= 0.774 min. For the constituent with peak area of 25%.
Key result
Type:
log Pow
Partition coefficient:
0.6
Temp.:
20 °C
pH:
7
Remarks on result:
other: Mean RT= 1.145 min. For the constituent with peak area of 5.6%.
Details on results:
- Retention times of reference items used for calibration: see table below;
- Details of fitted regression line: log k' = 0.631 log Pow – 0.441 (r = 0.998, n=12);
- Chromatogram and graph of regression line attached;
- The chromatogram of test item showed one major peak and several small peaks.
- The log Pow and Pow values of the major peak could not be calculated because tr < tr of formamide.
- 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)

0.613

0.607

0.610

 

 

 

2-Butanone

0.928

0.927

0.928

0.3

 

 

Benzylalcohol

1.888

1.852

1.870

1.1

 

 

Nitrobenzene

3.849

3.764

3.807

1.9

 

 

Toluene

12.728

12.450

12.589

2.7

 

 

Bromobenzene

16.800

16.422

16.611

3.0

 

 

1,4-Dichlorobenzene

32.138

31.478

31.808

3.4

 

 

Test item – peak 1

0.578

0.577

0.578

n.a.

n.a.

70

Test item – peak 2

0.774

0.771

0.773

-0.2 (1)

0.61

25

Test item – peak 3

1.145

1.141

1.143

0.6

4.0

5.6

(1)   Estimated value, calculated by extrapolation of the calibration curve.

Applicant's summary and conclusion

Conclusions:
The log Pow at pH 7 and ca. 20°C for the constituent with peak area of 70%, 25% and 5.6% was determined to be <0.3, -0.2 and 0.6, 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, 6 references substances with known log Pow values (at ca. 20°C) ranging from 0.3 to 3.4 were used. Duplicate injections of unretained substance, reference substances and test item in an UPLC-UV system. The mobile phase was 40/60 (v/v) methanol/buffer pH 7 and the wavelength of detection was 210 nm. Each chromatogram of the test item showed three substance peaks. The major component (70% area) eluted before the unretained component and before the reference substance with log Pow of 0.3. From this it can be concluded that the log Pow for this component is < 0.3. Substituting the mean retention times of the other two peaks in the regression line yielded a log Pow values of -0.2 and 0.6. Pow= 0.61 and 4.0, resp.