Disodium 5-[[4-[(2-bromo-1-oxoallyl)amino]-2-sulphonatophenyl]azo]-4-hydroxy-6-(methylamino)naphthalene-2-sulphonate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 July 2014 to 25 July 2014

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:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - HPLC Method)

Deviations:

no

GLP compliance:

no

Type of method:

flask method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: SBL/036/LR5B

Type:

log Pow

Temp.:

20 °C

Remarks on result:

other: pH not specified

Type:

Pow

Partition coefficient:

0.003

Temp.:

20 °C

Remarks on result:

other: pH not specified

Details on results:

Preliminary visual estimation of the n-octanol solubility:
100 mg of the test item were stirred with different amounts of n-octanol at room temperature and visually checked for any undissolved particles. According to this preliminary test, the solubility of the test item in n-octanol is below 100 mg/l (without correction of the purity).

Calculation of the partition coefficient log Pow from the preliminary tests:
The partition coefficient Pow may be estimated from the saturation concentrations in n-octanol and water by the following equation:
Pow = cs octanol /cs water
s= saturation
With the data obtained from the experiments in chapter 3.5.1 (cs <100 mg/l) and in the preliminary test (water solubility: cs = 7.1 g/l), the partition coefficient was calculated as log Pow < -1.9
Due to the fact, that the n-octanol solubility is nearly the LoQ, the partition coefficient n-octanol/water has to be estimated from the individual solubility in water and n-octanol.

Determination of the solubility in the n-octanol phase: Flask Methods: Average (3): 23.0 mg/l.

Calculation of the partition coefficient log Pow from the individual solubility:

By means of the flask method, the saturation concentration of the test item in n-octanol was determined to: 23.0 mg/l.

By means of the flask method, the saturation concentration of the test item in water was determined to: 7.1 g/l.

Pow = cs octanol /cs water: Pow = cs octanol /cs water

Pow: Pow = cs octanol /cs water

Pow: 0.003239

log Pow: -2.49

The partition coefficent n-octanol/water of the test item at 20 °C, from the individual solubility in water and n-octanol, was determined to: log Pow = - 2.49

Conclusions:

The n-octanol/water partition coefficient of FAT 92354/B at 20 °C, from the individual solubilities in n-octanol and water, was determined to be - 2.49 (log Pow; Pow = 0.003239).

Executive summary:

The study was carried out to determine the n-octanol / water partition coefficient of FAT 92354/B according to the EU A.8, OECD 107 and OECD 117 guidelines using the flask method. For the main test, three flasks were prepared with about 1000 mg and 5 ml n-octanol. The concentration were quantified with absorbance vs concentration. The standards were prepared by dissolving the test item in n-octanol and diluting the stock solutions. The UV was checked (calibration). In the preliminary visual estimation of the n-octanol solubility, 100 mg of the test item was stirred with different amounts of n-octanol at room temperature and visually checked for any undissolved particles. According to this preliminary test, the solubility of the test item in n-octanol is below 100 mg/l (without correction of the purity). Hence, it was chosen to calculate the partition coefficient (log Pow) from the individual solubilities by means of the flask method. The saturation concentration of the test item in n-octanol was determined to be 23.0 mg/l. The saturation concentration of the test item in water was determined to be 7.1 g/l.

 

Based on the study results, the n-octanol/water partition coefficient of FAT 92354/B at 20 °C, from the individual solubilities in n-octanol and water, was determined to be - 2.49 (log Pow; Pow = 0.003239).

Description of key information

The n-octanol/water partition coefficient of FAT 92354/B at 20 °C, from the individual solubilities in n-octanol and water, was determined to be - 2.49 (log Pow; Pow = 0.003239).

Key value for chemical safety assessment

Log Kow (Log Pow):

-2.49

at the temperature of:

20 °C

Additional information

The study was conducted to determine the n-octanol/water partition coefficient of FAT 92354/B according to the EU A.8, OECD 107 and OECD 117 guidelines using the flask method. For the main test, three flasks were prepared with about 1000 mg and 5 ml n-octanol. The concentration were quantified with absorbance vs concentration. The standards were prepared by dissolving the test item in n-octanol and diluting the stock solutions. The UV was checked (calibration). In the preliminary visual estimation of the n-octanol solubility, 100 mg of the test item was stirred with different amounts of n-octanol at room temperature and visually checked for any undissolved particles. According to this preliminary test, the solubility of the test item in n-octanol is below 100 mg/l (without correction of the purity). Hence, it was chosen to calculate the partition coefficient (log Pow) from the individual solubilities by means of the flask method. The saturation concentration of the test item in n-octanol was determined to be 23.0 mg/l. The saturation concentration of the test item in water was determined to be 7.1 g/l.

 

Based on the study results, the n-octanol/water partition coefficient of FAT 92354/B at 20 °C, from the individual solubilities in n-octanol and water, was determined to be - 2.49 (log Pow; Pow = 0.003239).