Strontium 3-hydroxy-4-[(1-sulfonato-2-naphthyl)azo]-2- naphthoate 5/2 hydrate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Analytical method:

not specified

Key result

Type:

log Pow

Remarks on result:

not determinable

Remarks:

The estimation method was applied for the determination of the Pow of R507-2. However, the partition coefficient (n-octanol/ water), Pow, of R507-2 could not be calculated as a quotient of the n-octanol solubility and the water solubility due to the limited solubility in both water and n­ octanol. Due to the nature of the test substance, an alternative method cannot be used.

Details on results:

Preliminary test
The content of test substance dissolved in the n-octanol sample was < 2.68 x 10-3 g/L

n-Octanol solubility
No test substance was detected in any of the sub-samples taken from the flasks after 24, 48 and 72 hours of stirring, respectively.

In order to estimate the n-octanol solubility, the limit of detection (LOD) was determined. From a chromatogram of a 0.05 mg/I test substance solution the noise level was determined to be 35 µAU and the peak height was 330 µAU. Using these values, the limit of detection was 0.016 mg/L. Taking a dilution factor of 67 into account this corresponds to a LOD of 1.1 mg/L in end solution.

No test substance was detected in the pre-treated samples from the blank octanol mixture. The n-octanol solubility of R507-2 is < 1.1 x 10-3 g/L at 19.9 ± 0.6 °C.

Water solubility
Information on the water solubility of the test substance was < 7 x 10-5 g/L.

Conclusions:

The estimation method was applied for the determination of the Pow of R507-2. However, the partition coefficient (n-octanol/ water), Pow, of R507-2 could not be calculated as a quotient of the n-octanol solubility and the water solubility due to the limited solubility in both water and n­ octanol. Due to the nature of the test substance, an alternative method cannot be used.

Executive summary:

The estimation method was applied for the determination of the Pow of R507-2. However, the partition coefficient (n-octanol/ water), Pow, of R507-2 could not be calculated as a quotient of the n-octanol solubility and the water solubility due to the limited solubility in both water and n­ octanol. Due to the nature of the test substance, an alternative method cannot be used.

Description of key information

The estimation method was applied for the determination of the Pow of R507-2. However, the partition coefficient (n-octanol/ water), Pow, of R507-2 could not be calculated as a quotient of the n-octanol solubility and the water solubility due to the limited solubility in both water and n­ octanol. Due to the nature of the test substance, an alternative method cannot be used.