Registration Dossier

Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
15 October 2018 - 08 November 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2019

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:
solid: particulate/powder
Details on test material:
- Physical appearance: off-white to beige powder
- Test item storage: at room temperature

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficientopen allclose all
Key result
Type:
log Pow
Partition coefficient:
3
Temp.:
20 °C
Remarks on result:
other: unbuffered mobile phase
Remarks:
main response
Key result
Type:
Pow
Partition coefficient:
960
Temp.:
20 °C
Remarks on result:
other: unbuffered mobile phase
Remarks:
main response
Key result
Type:
log Pow
Partition coefficient:
3.3
Temp.:
20 °C
Remarks on result:
other: unbuffered mobile phase
Remarks:
minor response
Key result
Type:
Pow
Partition coefficient:
1 900
Temp.:
20 °C
Remarks on result:
other: unbuffered mobile phase
Remarks:
minor response
Details on results:
- Retention times of reference substances used for calibration: see table below.
- Details of fitted regression line: log k' = 0.339 x log Pow – 0.823 (r = 0.994, n=16).
- Chromatogram and graph of regression line attached.
- The chromatogram of the test item showed one major and one minor test item related peak.
- 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
(%)

tr,1

tr,2

mean

Formamide (t0)

0.612

0.610

0.611

 

 

 

Benzylalcohol

0.788

0.791

0.790

1.1

 

 

Nitrobenzene

0.978

0.980

0.979

1.9

 

 

Toluene

1.572

1.577

1.575

2.7

 

 

1,4-Dichlorobenzene

2.048

2.055

2.052

3.4

 

 

Biphenyl

2.770

2.781

2.776

4.0

 

 

Dibenzyl

4.659

4.682

4.671

4.8

 

 

Triphenylamine

8.669

8.700

8.685

5.7

 

 

4,4’-DDT

12.691

12.735

12.713

6.5

 

 

Test item – major peak

1.552

1.550

1.551

3.0

9.6x102

94

Test item – minor peak

1.793

1.790

1.792

3.3

1.9x103

6.2

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

Applicant's summary and conclusion

Conclusions:
The log Pow of the substance at neutral pH and ca. 20°C was determined to be 3.0. Pow = 9.6E+2.
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, 8 references substances with known log Pow values ranging from 1.1 to 6.5 (at ca. 20°C) were used.

Duplicate injections of unretained substance, reference substances and test item were made into an UPLC-UV system. The mobile phase was 75/25 (v/v) methanol/water and the wavelength of detection was 210 nm.

Each chromatogram of the test item showed one major and one minor peak. The corresponding log Pow values were calculated from the reference substance regression line.

The Pow and log Pow values of the main response (94% based on peak area) at neutral pH were 9.6E+2 and 3.0, respectively.

The Pow and log Pow values of the minor response (6.2% based on peak area) at neutral pH were 1.9E+3 and 3.3, respectively.