Trisodium [μ-[3-[[4'-[[6-benzamido-1-hydroxy-3-sulpho-2-naphthyl]azo]-3,3'-dihydroxy[1,1'-biphenyl]-4-yl]azo]-4,5-dihydroxynaphthalene-2,7-disulphonato(7-)]]dicuprate(3-)

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 09 April, 2019 to 12 April, 2019

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

GLP compliance:

not specified

Type of method:

flask method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

Identification: FAT 11127/E TE
Lot: 2024 (Thailand)
Appearance: Dark blue powder

Analytical method:

high-performance liquid chromatography

Key result

Type:

Pow

Partition coefficient:

ca. 0.007

Temp.:

20 °C

Remarks on result:

other: pH not specified

Key result

Type:

log Pow

Partition coefficient:

ca. -2.16

Temp.:

20 °C

Remarks on result:

other: pH not specified

Individual Results

Preliminary Visual Estimation of the n-Octanol solubility

10 mg of the test item were stirred with different amounts of n-octanol at room temperature and visually checked for any undissolved particles. The test item did not dissolve in upto 900 ml n-octanol. According to this preliminary test the solubility of the test item in n-octanol is below 0.01 g/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

where s : saturation

With the data obtained from the experiments (cs octanol < 0.01 g/l) and the preliminary test (cs water = 0.255 g/l), the partition coefficient was calculated as log POW < -2.4.

Due to the fact that the estimated log Pow is below -2, the partition coefficient n-octanol/water has to be estimated from the individual solubilities in water and n-octanol.

Determination of the solubility in the n-Octanol phase: Flask Method

Average experiments A to C: 1.75 mg/l

The recovery ranged from 96.6 % to 99.5 % indicates a sufficient accuracy of the analytical method.

Calculation of the partition coefficient log Pow from the individual solubility in water and n-octanol

By means of the flask method, the saturation concentration of the test item in n-octanol was determined to: cs octanol = 0.00175 g/l

By means of the flask method, the saturation concentration of the test item in water was determined to: cs water = 0.255 g/l

Pow = cs octanol / cs water

0.00175 g/l / 0.255 g/l = 0.0069

log Pow = - 2.16

Conclusions:

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 be -2.16 (log Pow).

Executive summary:

The partition coefficent n-octanol/water of the test item (FAT 11127/E) was determined according to flask method speficied in OECD test guideline 107. Based on the individual solubility of test item in n-octanol and water, the n-octanol/water partition coefficient was determined to be -2.16 (log Pow).

Description of key information

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 be -2.16 (log Pow).

Key value for chemical safety assessment

Log Kow (Log Pow):

-2.16

at the temperature of:

20 °C

Additional information

The partition coefficent n-octanol/water of the test item (FAT 11127/E) was determined according to flask method speficied in OECD test guideline 107. Based on the individual solubility of test item in n-octanol and water, the n-octanol/water partition coefficient was determined to be -2.16 (log Pow).