Registration Dossier

Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
01 December 2010 – 21 January 2011
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study has been performed according to OECD and EC guidelines and according to GLP principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report Date:
2011

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.8 (Partition Coefficient)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
HPLC method
Partition coefficient type:
octanol-water

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): SX-1
- Molecular formula: C31H24N4O4
- Molecular weight: 516.55
- Substance type: Pale yellow powder
- Physical state: solid
- Analytical purity: 99.7%
- Lot/batch No.: 008809
- Expiration date of the lot/batch: 02 November 2012
- Stability under test conditions: Stable
- Storage condition of test material: At room temperature in the dark


Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficientopen allclose all
Type:
log Pow
Partition coefficient:
> 6.5
Temp.:
25 °C
pH:
ca. 7
Remarks on result:
other: at neutral pH
Type:
Pow
Partition coefficient:
> 3 162 277
Temp.:
25 °C
pH:
ca. 7
Remarks on result:
other: at neutral pH
Type:
log Pow
Partition coefficient:
4.2
Temp.:
25 °C
pH:
12
Remarks on result:
other: at basic pH
Type:
Pow
Partition coefficient:
15 849
Temp.:
25 °C
pH:
12
Remarks on result:
other: at basic pH

Any other information on results incl. tables

Calculation method

Calculation of the Pow

The Pow of the test substance was calculated to be 1.3 x 109 (log Pow 9.1) using the Rekker calculation method.

Calculation of the pKa

The following pKavalues in the logarithm range of 1 - 14 for acidic and basic groups in the molecular structure of the test substance were calculated using the Perrin calculation method:

- Non acidic groups

- Basic groups with pKa values of 11.2, 10.8, 10.4, 10.0

 

Pow at neutral pH

In the chromatogram of the test solution, one test substance related peak with a retention time of 37.2 minutes was observed. Under the same analytical conditions, the retention time of 2,4-DDT (log Pow = 6.5) was 24.9 minutes (i.e. elution at the isocratic part of the analytical method). Hence, it was concluded that the log Pow of test substance at neutral pH was > 6.5 (Pow> 3.2 x 106).

 

Pow at pH 12

In the chromatogram of the test solution, one test substance realed peak with a retention time of 3.3 minutes was observed.

 

The equation of the regression line was: log k’ = 0.423 x log Pow – 0.958 (r = 0.998, n = 12).

 

Pow of the test substance – basic conditions at pH 12

Substance

tr,1
[min]

tr,2
[min]

mean tr
(n=2)

log Pow

Pow

Area
%

 

 

 

 

 

 

 

Formamide (t0)

0.432

0.431

0.432

 

 

 

 

 

 

 

 

 

 

Nitrobenzene

0.721

0.715

0.718

1.9

 

 

Biphenyl

3.010

2.987

2.999

4.0

 

 

Dibenzyl

5.939

5.885

5.912

4.8

 

 

Fluoranthene

6.607

6.586

6.597

5.1

 

 

Triphenylamine

13.824

13.713

13.769

5.7

 

 

2,4-DDT

25.335

25.131

25.233

6.5

 

 

 

 

 

 

 

 

 

Test substance

3.326

3.331

3.329

4.2

1.6 x 104

100

 

 

 

 

 

 

 

 

Applicant's summary and conclusion

Conclusions:
The HPLC method was applied for the determination of the partition coefficient (Pow) of SX-1. The log Pow values of the test substance under basic conditions at pH 12 and at neutral pH were 4.2 and > 6.5, respectively.
 
Executive summary:

 

neutral pH

pH 12

Pow

log Pow

Area
%

Pow

log Pow

Area
%

 

 

 

 

 

 

 

Test substance

> 3.2x106

> 6.5

100

1.6x104

4.2

100