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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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:
12 May 2015 to 16 July 2015
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)
Version / remarks:
1995
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method A.8 (Partition Coefficient - Shake Flask Method)
Version / remarks:
2008
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of method:
flask method
Partition coefficient type:
octanol-water
Analytical method:
high-performance liquid chromatography
Key result
Type:
Pow
Partition coefficient:
< 0.001
Temp.:
22.5 °C
pH:
7.08
Key result
Type:
log Pow
Partition coefficient:
< -3.04
Temp.:
22.5 °C
pH:
7.08
Details on results:
PRELIMINARY TEST
- Estimated log10 Pow: -3.93

MAIN TEST
- The mean peak areas obtained for the standard, stock and sample solutions were:
Organic Phase:
Standard 1.04 mg/L: 1.5057 x 10^6
Standard 1.06 mg/L: 1.8245 x 10^6
Organic phase matrix blank (comparable to sample areas): 1.1515 x 10^6
Sample 1: 1.0890 x 10^6
Sample 2: 1.1858 x 10^6
Sample 3: 1.0014 x 10^6
Sample 4: 1.1517 x 10^6
Sample 5: 1.2301 x 10^6
Sample 6: 1.2914 x 10^6

Aqueous Phase:
Standard 15.7 mg/L: 1.4242 x 10^7
Standard 15.9 mg/L: 1.4491 x 10^7
Aqueous phase matrix blank: -
Sample 1: 1.0601 x 10^7
Sample 2: 1.0149 x 10^7
Sample 3: 1.0139 x 10^7
Sample 4: 1.0287 x 10^7
Sample 5: 9.9992 x 10^6
Sample 6: 1.0413 x 10^7
Stock solution A: 1.0697 x 10^7
Stock solution B: 1.0243 x 10^7

- The total weights (mg) and analysed concentration (mg/L) of the respective phases are shown in Table 2. pH of stock solution : 7.08. Temperature : 22.5 ± 0.5 °C.
- The partition coefficient for each sample is shown in Table 3. Overall Pow : <9.12 x 10^-4. Overall log10 Pow : <-3.04

- Validation: The linearity of the detector response with respect to concentration was assessed over the nominal concentration range of 0.8 to 2 mg/L in organic matrix and 5 to 30 mg/L in aqueous matrix. The results were satisfactory, with a goodness of fit (r2) of 0.9866 and 0.9997 being obtained for the organic and aqueous matrices, respectively.

DISCUSSION
- The determination of partition coefficient was performed using the shake flask method. This choice was supported by the estimated partition coefficient obtained in the preliminary estimation.
- The stock solution was prepared in n-octanol saturated water in place of water saturated n-octanol due to the insolubility of the test material in the organic phase. This deviation to the guidelines has been considered to have a negligible impact on the overall result, as it was more appropriate to use this solvent to obtain a more realistic partition coefficient value. The stock solution was adjusted to neutral pH, since it was not possible to avoid the ionization of the test material in solution.
- All glassware used for the test was silanised, and low adsorption HPLC vials were used, in an attempt to minimise any test material adsorption to the glassware.
- The limit value used for the concentration of the organic phases (<2 mg/L) was derived from the nominal concentration of the standards (1 mg/L), which produced a response greater than the corresponding matrix blank, corrected for the dilution factor (2).
- The responses of the duplicate standards prepared for the analysis of the organic phases were significantly different. However, this inconsistency had no negative effect on the results, since the concentration of the organic phases was given as a limit value; therefore, it was sufficient to prove that the peak areas of all organic samples and matrix blank were lower than the peak areas of the respective standards.

Table 2: The total weights (mg) and analysed concentration (mg/L) of the respective phases during the study.

Sample Number

Total Weight (mg)

Organic Phase

 

% Recovery

Analysed Concentration (mg/L)

Weight (mg)

Analysed Concentration (mg/L)

Weight (mg)

pH

1

57.4

<2

<0.1

2.33 x 10^3

58.1

6.91

>101

2

62.0

<2

<0.1

2.23 x 10^3

60.1

6.88

>97.0

3

91.8

<2

<8x10^-2

2.22 x 10^3

89.0

7.08

>96.9

4

91.8

<2

<8x10^-2

2.26 x 10^3

90.2

7.05

>98.3

5

129

<2

<6x10^-2

2.19 x 10^3

123

7.32

>95.5

6

129

<2

<6x10^-2

2.28 x 10^3

128

7.34

>99.5

 

Table 3: Determination of the Partition Coefficient

Sample Number

Organic/Aqueous Volume Ratio

Partition Coefficient

Log10 Pow

Overall Partition Coefficient

1

2:1

<8.60 x 10-4

<-3.07

<8.99 x 10^-4

2

<8.99 x 10-4

<-3.05

3

1:1

<8.99 x 10-4

<-3.05

<8.99 x 10^-4

4

<8.87 x 10-4

<-3.05

5

1:2

<9.12 x 10-4

<-3.04

<9.12 x 10^-4

6

<8.76 x 10-4

<-3.06
Conclusions:
Under the conditions of this study, the partition coefficient of the test material has been determined to be less than 9.12 x 10^-4 at 22.5 ± 0.5 °C, log10 Pow less than -3.04, at 22.5 °C pH 7.08.
Executive summary:

The partition coefficient of the test material was determined in accordance with the standardised guidelines OECD 107 and EU Method A.8, under GLP conditions using the shake flask method.

The test system consisted of an aqueous and an n-octanol phase in the same vessel. A defined amount of test item was added (pre-dissolved in the appropriate phase). Partitioning of the test item between both phases was achieved by inversion of the mixture. The test temperature was in the range of 20 °C to 25 °C and kept constant (± 1 °C).

Under the conditions of this study, the partition coefficient of the test material has been determined to be less than 9.12 x 10^-4 at 22.5 ± 0.5 °C, log10 Pow less than -3.04, at 22.5 °C pH 7.08.

Description of key information

Under the conditions of this study, the partition coefficient of the test material has been determined to be less than 9.12 x 10^-4 at 22.5 ± 0.5 °C, log10 Pow less than -3.04, at 22.5 °C pH 7.08.

Key value for chemical safety assessment

Log Kow (Log Pow):
-3.04
at the temperature of:
22.5 °C

Additional information

The partition coefficient of the test material was determined in accordance with the standardised guidelines OECD 107 and EU Method A.8, under GLP conditions using the shake flask method. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

The test system consisted of an aqueous and an n-octanol phase in the same vessel. A defined amount of test item was added (pre-dissolved in the appropriate phase). Partitioning of the test item between both phases was achieved by inversion of the mixture. The test temperature was in the range of 20 °C to 25 °C and kept constant (± 1 °C).

Under the conditions of this study, the partition coefficient of the test material has been determined to be less than 9.12 x 10^-4 at 22.5 ± 0.5 °C, log10 Pow less than -3.04, at 22.5 °C pH 7.08.