Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Partition coefficient

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
07 Jun - 29 Jul 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)
Qualifier:
according to guideline
Guideline:
other: EU Method A.8 - Appendix 1. Calculation/estimation methods
GLP compliance:
yes (incl. QA statement)
Remarks:
Swiss Federal Office of Public Health, Bern, Switzerland
Type of method:
estimation method (solubility ratio)
Partition coefficient type:
octanol-water
Analytical method:
high-performance liquid chromatography
Key result
Type:
log Pow
Partition coefficient:
-3.8
Temp.:
22 °C
pH:
ca. 8.5
Remarks on result:
other: determined by estimation method (solubility ratio)
Type:
log Pow
Partition coefficient:
-3.45
Temp.:
22 °C
pH:
ca. 8.5
Remarks on result:
other: Shake flask method; this value is below the applicability range of the method (-2 to 4)

Results for Partition Coefficient (n-octanol/water) Log POW

The measurement of test item in n-octanol solution saturated with test item gave a test item concentration of 34.5 ± 0.1 mg/L (0.152 mmol/L).

n-Octanol Saturated with Test Item

Sample No.

Measured Concentration in n-Octanol

[mg/L]

Mean ± SD

[mg/L]

1

34.6

34.5 ± 0.1

2

34.4

3

34.6

The tabulated values of the samples represent rounded results obtained by calculation using the exact data.

 

The results of the individual measurements of both phases and the calculation of the log POW values are given in the following table.

n-Octanol/Water Ratio

Measured Concentration in n-Octanol

[mg/L]

Measured Concentration in water

[mg/L]

log POW

Mean

SD

9

0.0987

293

-3.472

-3.45

±0.08

0.103

301

-3.465

18

0.0669

149

-3.349

0.0658

150

-3.358

4.5

0.190

625

-3.516

0.189

658

-3.541

The tabulated values of the samples represent rounded results obtained by calculation using the exact data.

 

The following value for the log POW was obtained: -3.45 ± 0.08

 

Considering that this value is below the applicability range of the shake-flask method (-2 to 4), the log POW was estimated using the n-octanol solubility and the water solubility (see section 4.8 for more details on water solubility) as recommended in the EU Method A.8 - Annex 1.

The log POW value was calculated using the water solubility value 219 ± 4 g/L and the n-octanol solubility value 34.5 ± 0.1 mg/L.

The resulting estimated log POW is -3.80 ± 0.01.

 

Data for Analytical Method

Two analyzed analytical control samples (water saturated with n-octanol and n-octanol saturated with water) did not significantly affect the chromatogram at the retention time of the test item. The calibration solutions contained a peak specific for the test item, which area changed accordingly with known concentration.

The R² fit of the calibration curve used was 0.9999. This reflects the fit of the analytical system within the calibration range of 0.544 - 109 mg test item /L.

The analytical method was verified by preparing quality control samples in water and n-octanol.

Quality control samples accurately fortified at relevant concentrations of test item (3.02 mg test item/L and 0.102 mg test item/L n-octanol), were prepared, extracted and analyzed. The recoveries for the extracted quality control samples ranged from 89 to 96 %.

Quality control samples at levels of 4.16, 29.4 and 87.4 mg/L in water (saturated with n-octanol) were analyzed and evaluated against the calibration curve and yielded to recoveries of 92 to 95 %.

These data show the correct preparation of the calibration standards and the applicability of the extraction method.

 

Conclusion

During this study, the partition coefficient (n-octanol/water) log POW of the test item was calculated from the individual solubilities of the test item in n-octanol (measured in this study) and water (see section 4.8).

The following value for the log POW was obtained: -3.80 ± 0.01

Conclusions:
A n-octanol/water partition coefficient of log Pow = -3.80 at 22 °C, pH ca. 8.5 was determined for the test substance according to EU Method A.8

Description of key information

Log POW: -3.8 at 22 °C, pH ca. 8.5 (EU Method A.8 - Appendix 1, estimation method (solubility ratio))

Key value for chemical safety assessment

Log Kow (Log Pow):
-3.8
at the temperature of:
22 °C

Additional information

A log POW of -3.45 ± 0.08 was obtained according to OECD Guideline 107 (shake-flask method). Considering that this value is below the applicability range of the method (-2 to 4), the log POW was estimated using the n-octanol solubility and the water solubility (see section 4.8 for more details on water solubility) as recommended in the EU Method A.8 - Appendix 1.