Dibutyl [[bis[(2-ethylhexyl)oxy]phosphinothioyl]thio]succinate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 November 2017 to 13 September 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

CAS No.: 68413-48-9
Purity: 84%
Description: Pale yellow, clear liquid

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

> 6.5

Temp.:

25 °C

pH:

5

The log partition coefficient (log Pow) values determined for the two components detected in the test substance were as follows:

Diluted 

Peak	Test Substance	Mean Retention Time (minutes)	Mean Calculated log Pow	Mean Reported log Pow
1	Component 1	15.448	5.211	5.2
2	Component 2	85.653	7.724	7.7*

*Exceeds the latest mean retention time of the reference standards (4,4’-DDT, 39.3 minutes); log Pow of the test substance was therefore extrapolated using a linear regression model.

 

Undiluted 

Peak	Test Substance	Mean Retention Time (minutes)	Mean Calculated log Pow	Mean Reported log Pow
1	Component 1	15.421	5.208	5.2
2	Component 2	85.173	7.716	7.7*

 *Exceeds the latest mean retention time of the reference standards (4,4’-DDT, 39.3 minutes); log Pow of the test substance was therefore extrapolated using a linear regression model.

 

The test substance contains the major component and a known impurity. Based on the chromatography from the test substance characterization by the Sponsor, the impurity elutes prior to the main constituent, under similar conditions as used in this study. It is therefore reasonable to postulate that the impurity is Component 1 and the main constituent is Component 2. 

Conclusions:

The partition coefficient (log Pow) of the substance was determined to be greater than 6.5, the highest Log Kow of reference standards tested (p,p-DDT).

Executive summary:

In a study performed to the standardised guideline OECD 117, under GLP conditions, the partition coefficient (log Pow) of the substance was determined by the reverse-phase high-performance liquid chromatography (HPLC) method.

The partition coefficient (log Pow) of the substance was concluded to be greater than 6.5, the highest Log Kow of reference standards tested (p,p-DDT). 

Description of key information

In a study performed to the standardised guideline OECD 117, under GLP conditions, the partition coefficient (log Pow) of the substance was determined by the reverse-phase high-performance liquid chromatography (HPLC) method.

The partition coefficient (log Pow) of the substance was concluded to be greater than 6.5, the highest Log Kow of reference standards tested (p,p-DDT) (Smithers Viscient, 2018).

Key value for chemical safety assessment

Log Kow (Log Pow):

6.5