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Physical & Chemical properties

Partition coefficient

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Reference
Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
from 2018-01-15 to 2018-02-06
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reference:
Composition 0
Qualifier:
according to
Guideline:
OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.8 (Partition Coefficient - 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 (incl. certificate)
Type of method:
flask method
Partition coefficient type:
octanol-water
Test material information:
Composition 1
Specific details on test material used for the study:
Batch No.: VPS9016001
Purity: 97.3 %
Analytical method:
high-performance liquid chromatography
Key result
Type:
Pow
Partition coefficient:
0.021
Temp.:
20 °C
pH:
>= 2.37 - <= 2.57
Key result
Type:
log Pow
Partition coefficient:
-1.69
Temp.:
20 °C
pH:
>= 2.37 - <= 2.57

Calibration

The calibration solutions were prepared in 0.1 – 20 µg/mL range.

Table 1. Regression data

Analytical occasion

Constant

X Coefficient

R. Squared

24 January 2018

12328

161035

0.9998

 

Results

The test item concentrations were calculated with the help of the calibration equation.

Table 2. Measured concentration

Ratio of solvents
(n-Octanol : Water)

Measured concentration in
n-octanol phase
(µg/mL)

Measured concentration in
aqueous phase
(µg/mL)

pH

 

1:1

7.546

386.9

2.44

 

7.626

377.2

2.46

 

7.545

394.8

2.46

 

Mean

7.572

386.3

2.45

 

RSD %

1

2

-

 

Measured quantity of test item (Mo; Mw)

189 µg

9657 µg

-

 

Total nominal quantity of test item (Ms)

9374µg

 

Total quantity of test item (Mo+Mw)

9847 µg

 

Recovery

105 %

Ratio of solvents
(n-Octanol : Water)

Measured concentration in
n-octanol phase
(µg/mL)

Measured concentration in
aqueous phase
(µg/mL)

pH

 

2:1

14.33

565.5

2.38

 

15.27

565.2

2.36

 

15.31

575.5

2.37

 

Mean

14.97

568.7

2.37

 

RSD%

4

1

-

 

Measured quantity of test item (Mo; Mw)

499 µg

9469 µg

-

 

Total nominal quantity of test item (Ms)

9374µg

 

Total quantity of test item (Mo+ Mw)

9969 µg

 

Recovery

106 %

 

1:2

4.541

282.4

2.58

 

4.485

285.6

2.57

 

4.664

288.3

2.56

 

Mean

4.563

285.4

2.57

 

RSD%

2

1

-

 

Measured quantity of test item (Mo; Mw)

76 µg

9519 µg

-

 

Total nominal quantity of test item (Ms)

9374µg

 

Total quantity of test item (Mo+ Mw)

9595 µg

 

Recovery

102 %

 

 

 

 

Table 3: Calculated partition coefficient (Pow) and log Pow

 

Ratio of solvents
(n-Octanol : Water)

Partition coefficient

Log Partition coefficient

 

Pow

Log Pow

 

1:1

0.0196

-1.71

 

2:1

0.0263

-1.58

 

1:2

0.0160

-1.80

 

Mean all

0.0206

-1.69

 

Conclusions:
In conclusion, the partition coefficient (Pow) of the test item in an n-octanol - water two-phase system was determined to be 0.0206 ± 0.0035 (95 % confidence interval) using shake flask method. The log Pow is -1.69 ± 0.073 (95 % confidence interval).
Executive summary:

A study was conducted in accordance with OECD TG 107, Regulation (EC) No 440/2008 method A.8 and OPPTS 830.7550 to determine the partition coefficient of the test substance using the shake flask method. A stock solution of the test substance was prepared in n-octanol presaturated with water. The samples in the octanol phase were extracted with water. The water phase was diluted and analysed using HPLC. Test vessels with octanol/water mixture in different ratios were shaken for 5 minutes by hand. Separation of the two phases was achieved by centrifugation at 20 °C (5 min, 4000 rpm). Then the two phases were analysed using HPLC. The partition coefficient of the test item was determined to be 0.0206. The log Pow is -1.69.

Description of key information

The partition coefficient of the test item was determined to be 0.0206. The log Pow is -1.69.

Key value for chemical safety assessment

Log Kow (Log Pow):
-1.69
at the temperature of:
20 °C

Additional information

A study was conducted in accordance with OECD TG 107, Regulation (EC) No 440/2008 method A.8 and OPPTS 830.7550 to determine the partition coefficient of the test substance using the shake flask method. A stock solution of the test substance was prepared in n-octanol presaturated with water. The samples in the octanol phase were extracted with water. The water phase was diluted and analysed using HPLC. Test vessels with octanol/water mixture in different ratios were shaken for 5 minutes by hand. Separation of the two phases was achieved by centrifugation at 20 °C (5 min, 4000 rpm). Then the two phases were analysed using HPLC. The partition coefficient of the test item was determined to be 0.0206. The log Pow is -1.69.