m,m'-[carbonylbis[imino(3-methoxy-p-phenylene)azo]]bis(benzenesulphonic) acid, compound with 2,2'-iminodiethanol (1:2)

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 105

Version / remarks:

see 'Principles of method if other than guideline'

Principles of method if other than guideline:

Octanol solubility was determined equivalent to OECD guideline 105 'water solubility'. Afterwards the partition coefficient was determined by calculation.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Remarks:

Octanol solubility was determined equivalent to OECD guideline 105 'water solubility'. Afterwards the partition coefficient was determined by calculation.

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

> -4.06

Temp.:

20 °C

Remarks on result:

other: pH is not reported

Details on results:

The estimation of the log POW is performed by calculation with the determined water solubility and the determined 1-octanol solubility. The determined water solubility is 150.2 g/L. The highest determined value for 1-octanol solubility afte 10 days is 13.2 mg/L. As the equilibrium for the 1-octanol solubility was not reached (uprising trend until day 10), the result is given as: logKow > -4.06.
As long as the octanol solubility is lower than the water solubility which is assumed, the logKow is < 0.

Results of individual determinations:

1 -Octanol solubility test at 20°C	Flask C1	Flask B1	Flask A1	Flask C	Flask B	Flask A
Concentration of Bayscript yellow GGN [mg/L]	2.39	4.42	6.36	6.21	8.52	13.17
Stirring time at 30°C (+1 day at 20°C) [days]	1	2	3	5	7	10

Conclusions:

The partition coefficient was calculated by water and octanol solubility resulting in a logKow of > -4.06.

Executive summary:

The 1-octanol solubility of the test item Bayscript Yellow GGN was determined with the shake flask method at 20 °C based on OECD 105 and OPPTS 830.7840.

The concentration of the test item in the test solutions was determined by HPLC analysis with UV detection.

First tests were performed over one, two and three days. In those flasks there was an uprising trend present and therefore another test period was started for five, seven and ten days.

The values for the 1-octanol solubility of Bayscript Yellow GGN at 20 °C were determined between approx. 2.4 and 13.2 mg/L.

The estimation of the log POW is performed by calculation with the determined water solubility and the determined 1-octanol solubility. The determined water solubility is 150.2 g/L. The highest determined value for 1-octanol solubility after 10 days is 13.2 mg/L. The calculation with these values (150.2 g/L and 13.2 mg/L) gives an estimated log POW of -4.06. As the equilibrium for the 1-octanol solubility was not reached (uprising trend until day 10), the result is given as:

log POW > -4.06

As long as the octanol solubility is lower than the water solubility which is assumed, the log POW is < 0.

Description of key information

The 1-octanol solubility of the test item Bayscript Yellow GGN was determined with the shake flask method at 20 °C based on OECD 105 and OPPTS 830.7840.

The values for the 1-octanol solubility of Bayscript Yellow GGN at 20 °C were determined between approx. 2.4 and 13.2 mg/L.

The estimation of the log POW is performed by calculation with the determined water solubility and the determined 1-octanol solubility. The determined water solubility is 150.2 g/L. The highest determined value for 1-octanol solubility is 13.2 mg/L. The calculation with these values (150.2 g/L and 13.2 mg/L) gives an estimated log POW of -4.06. As the equilibrium for the 1-octanol solubility was not reached (uprising trend until day 10), the result is given as:

log POW > -4.06

As long as the octanol solubility is lower than the water solubility which is assumed, the log POW is < 0.

Key value for chemical safety assessment

Log Kow (Log Pow):

-4.06

at the temperature of:

20 °C

Additional information

The dissolved test item is just existent in its dissociated form in all relevant pH-values. Based on this effect, a shift appears in the chromatograms of the HPLC-method in comparison to the reference substances depending on the eluent, e.g. the use of 40:60 ACN:water results in a different partition coefficient than 45:55 ACN:water. Therefore, the result of studies executed according to OECD 117 have to be declared as not reliable for the test substance.