[No public or meaningful name is available]

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Rekker calculation method (Pow)

Principles of method if other than guideline:

The Rekker calculation method was performed for a preliminary estimation of the partition coefficient (n-octanol/water), Pow. Although the calculation method yielded a log Pow value >6 which is out of the applicability range of the HPLC method, the HPLC method was used to confirm the result of the calculation method.

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

benzene, 1,4-bis[2-[3,5-dimethoxy-4-(1- methylpropoxy)phenyl]ethenyl]-

Cas Number:

586410-55-1

Molecular formula:

C34 H42 O6

IUPAC Name:

benzene, 1,4-bis[2-[3,5-dimethoxy-4-(1- methylpropoxy)phenyl]ethenyl]-

Details on test material:

Read-across from CASRN586410-55-1 to the substance defined in section 1 allowed by belgian authority.
Stocksolutions for the HPLC method:
A 1254mg/l stock solution of the test substance was prepared in acetonitrile. The test solution was prepared by diluting the stock solution by a factor of 100 with mobile phase. This resulted in final concentration of 12.5mg/l. The test substance blank solution was prepared by adding 50µl acetonitrile to a 5.0ml volumetric flask. This flask was subsequently fileld up to the mark with mobile phase.
A 1008mg/l solutionof 2,4-DDT in methanol (HPLC grade) was diluted by a factor of 200 with mobile phase. This solution was used as the reference solution. The corresponding blank solution was prepared by adding 50µl methanol to a 10.0ml volumetric flask. This flask was subsequently filled up to the mark with mobile phase.

Results and discussion

Partition coefficient

Type:

log Pow

Partition coefficient:

> 12

Remarks on result:

other: Rekker calculation method

Details on results:

- Calculation of the dissociation constant (pKa): from the structural formula, no pKa values were calculated using the Perrin's calculation method. At neutral pH, >90% of the test substance is in a non-ionised form. Therefore, the aqueous part of the mobile phase during the HPLC method was not buffered.
- Calculation of the Pow: log Pow=12.0
- HPLC method: One large test subtance peak and one small test substance peak were observed at retention times of 18.1 and 17.5 minutes respectively, while the retention time of 2,4-DDT (log Pow=6.2) was 10.0 minutes. Hence, it was concluded that the log Pow of the test substance >6.2.Althoug the results of the calculation method and the HPLC were in agreement, the result of the calculation method is reported above because Pow of the test substance was out of the applicability range of the HPLC method.

Applicant's summary and conclusion

Conclusions:

Due to the above mentioned high log Pow (>4), the low water solubility (<1mg/l), the 48EC50 and 72LC50 which might both be >100mg/l and the non-readily biodegradability, the substance should be classified for 'chronic aquatic toxicity' (DSD: R53, CLP: cat.4).