1,4-bis[[4-(1,1-dimethylethyl)phenyl]amino]-5,8-dihydroxyanthraquinone

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Version / remarks:

(adopted, May 2008)

Deviations:

yes

Remarks:

The column temperature was 40 °C.

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

10.7

Temp.:

25 °C

pH:

5.3

Remarks on result:

other: Retention time [tr] (min): 64.355

Details on results:

The reference Pow-values in the OECD-guideline presumably refer to 25 °C. Even though the column temperature was 40 °C, this temperature is without influence on the result of the determination. The calibration was done referring to Pow- values of reference substances determined at 25 °C.

The validity criteria concerning repeatability and reproducibility have been met.

Conclusions:

The partition coefficient (log Pow) of 10.7 was determined at 25 °C.

Executive summary:

The partition coefficient (Pow) was determined according to the HPLC method at 40 °C. In order to comply with the guideline OECD 117 and considering environmental relevance, buffered water at pH 5 was chosen. The reference Pow-values in the OECD-guideline presumably refer to 25 °C. Even though the column temperature was 40 °C, this temperature is without influence on the result of the determination. The calibration was done referring to Pow- values of reference substances determined at 25 °C. For the determination of the partition coefficient (Koc) four calibration standards with log Koc from 1.7 -5.7 are established in the EG-test method. As no calibration standard with log Pow > 5.7 is established in the EG-test method, two new reference substances (bis(2-ethylhexyl)phthalate and decachlorobiphenyl) were used in this test. For both reference substances the log Pow–values were determined by the slow stirring method. The log Pow-values of 7.5 for bis(2 -ethylhexyl)phthalate and the log Pow of 8.3 for decachlorobiphenyl were published by Jack de Bruin, Frans Busser, Willem Seinen and Joop Hermens in the ‘Environmental Toxicology and Chemistry, Vol 8, pp 499-512, 1989. The chromatogram of C.I. Solvent Green 28 showed one signal eluting at 64.4 minutes. No calibration substance with a Pow–value above the value for the signal of the test item was available. For this reason the results for this signal was extrapolated. The partition coefficient (log Pow) of 10.7 was determined at 25 °C. The validity criteria concerning repeatability and reproducibility have been met.

Description of key information

The partition coefficient (log Pow) of 10.7 was determined at 25 °C.

Key value for chemical safety assessment

Log Kow (Log Pow):

10.7

at the temperature of:

25 °C

Additional information

The validity criteria concerning repeatability and reproducibility have been met.