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Physical & Chemical properties

Partition coefficient

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Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 830.7550 (Partition Coefficient, n-octanol / H2O, Shake Flask Method)
Deviations:
no
GLP compliance:
yes
Type of method:
flask method
Partition coefficient type:
octanol-water

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Details on test material:
- Purity: 100%

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficientopen allclose all
Key result
Type:
Pow
Partition coefficient:
3.446
Temp.:
20 °C
Remarks on result:
other: Pow = 3.446 ± 0.616, log Pow = 0.53 ± 0.08
Remarks:
Milli-Q water, no pH reported
Key result
Type:
Pow
Partition coefficient:
101.934
Temp.:
20 °C
pH:
4
Remarks on result:
other: Pow = 101.934 ± 8.556, log Pow = 2.01 ± 0.03
Key result
Type:
Pow
Partition coefficient:
0.531
Temp.:
20 °C
pH:
7
Remarks on result:
other: Pow = 0.531± 0.013, log Pow = -0.28 ± 0.01
Key result
Type:
Pow
Partition coefficient:
0.015
Temp.:
20 °C
pH:
9
Remarks on result:
other: Pow = 0.0149 ± 0.0025, log Pow = -1.83 ± 0.07

Any other information on results incl. tables

The analysed concentration of the test substance stock solutions prepared in n-octanol presaturated for the tests with Milli-Q water and pH 4.0, 7.0, and 9.0 aqueous buffer solutions were 8.647, 7.743, 8.305, and 7.826 µg/mL, respectively.

 The mean partition coefficient log Pow(Pow) of the test substance is presented below:

OCTANOL-AQUEOUS PHASE

RATIO

MEAN POW

MEAN LOG POW

Octanol-Milli-Q Water

1:1

3.018

0.48

1:2

4.23

0.63

2:1

3.09

0.49

Octanol-pH 4.0

1:1

101.714

2.01

1:2

111.422

2.05

2:1

92.666

1.97

Octanol-pH 7.0

1:1

0.54

-0.27

1:2

0.527

-0.28

2:1

0.527

-0.28

Octanol-pH 9.0

1:1

0.0158

-1.8

1:2

0.0158

-1.81

2:1

0.0131

-1.89

 The overall mean partition coefficient log Powand Powof the test substance at 20 ± 1ºC is presented below:

OCTANOL-AQUEOUS PHASE

OVERALL MEAN MEAN POW± S.D.

OVERALL MEAN LOG POW± S.D.

Octanol-Milli-Q Water

3.446 ± 0.616

0.53 ± 0.08

Octanol-pH 4.0

101.934 ± 8.556

2.01 ± 0.03

Octanol-pH 7.0

0.531± 0.013

-0.28 ± 0.01

Octanol-pH 9.0

0.0149 ± 0.0025

-1.83 ± 0.07

Applicant's summary and conclusion

Conclusions:
The pH has a significant effect on the octanol / water partition coefficient (Pow) of the test substance.
log Pow = -0.28 at pH 7 and 20°C
Pow = 0.531 at pH 7 and 20°C

Executive summary:

The study was conducted to determine the partition coefficient of the test substance. The partition coefficient was determined according to OECD Guideline 107 and OPPTS 830.7550. The study was conducted using Milli-Q water and pH 4.0, 7.0 and 9.0 aqueous buffer solutions to determine the effect of pH on the partition coefficient of the test substance.

The overall mean partition coefficient log Pow and Pow of the test substance at 20 ± 1ºC is presented below.

OCTANOL-AQUEOUS PHASE

OVERALL

MEAN POW± S.D.

OVERALL MEAN

LOG POW± S.D.

Octanol-Milli-Q Water

3.446 ± 0.616

0.53 ± 0.08

Octanol-pH 4.0

101.934 ± 8.556

2.01 ± 0.03

Octanol-pH 7.0

0.531± 0.013

-0.28 ± 0.01

Octanol-pH 9.0

0.0149 ± 0.0025

-1.83 ± 0.07

.