N-(4-amino-9,10-dihydro-3-methoxy-9,10-dioxo-1-anthryl)-4-methylbenzenesulphonamide

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 October, 2013 to 20 November, 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

GLP compliance:

no

Type of method:

shake-flask method to: flask method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

Test material: FAT 36034/W
Appearance: Pink powder

Analytical method:

photometric method

Key result

Type:

log Pow

Partition coefficient:

1.98

Temp.:

20 °C

pH:

7

Details on results:

Due to the fact, that the water solubility is nearly the LoQ, the partition coefficient n-octanol/water has to be estimated from the individual solubility in water and n-octanol.

Individual 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.

 

Table: Appearance of the test mixtures

Amount of test item in mg	Volume in ml	Total volume in ml	Stirring time	Appearance of mixture
10	5	5	60 min	undissolved
10	10	10	60 min	undissolved
10	50	50	60 min	dissolved

According to this preliminary test the solubility of the test item in n-octanol is above 200 mg/l (without correction of the purity).

Calculation of the partition coefficient log Pow from the preliminary tests

The partition coefficient P ow may be estimated from the saturation concentrations in n-octanol and water by the following equation:

P ow = cs octanol /cs water

s= saturation

With the data obtained from the experiments in chapter 3.5.1 (cs >200 mg/l) and in the preliminary test (water solubility: cs = 3.26 mg/l) the partition coefficient was calculated as log POW >1.8

Due to the fact, that the water 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

Table: Solubility of the test item –experiments A to D

Experiment	A	B	C	D (blank)
Amount of test item (mg)	500	500	500	--
Stirring time at 30 °C (h)	24	48	72	72
Aliquot of the flasks (ml)	0.15	0.15	0.15	0.15
End volume (ml)	10	10	10	10
Measured concentration (µg/ml)	3.63	4.06	4.63	--
Solubility (mg/l)	241.8	270.4	308.9	--

 

Table: Concentrations of the standards for recheck:

Standard	Measured concentration (µg/ml)	% Recovery
Standard 2 (c= 1.31 µg/ml)	1.35	102.8
Standard 3 (c= 6.55 µg/ml)	6.58	100.5
Standard 5 (c= 26.2 µg/ml)	25.9	98.9

 

Recovery range from 98.9 % to 102.8 % indicates a sufficient accuracy of the analytical method.

 

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: 308.9 mg/l.

By means of the flask method, the saturation concentration of the test item in water was determined to: 3.26 mg/l

Conclusions:

The partition coefficent n-octanol/water of the test item at 20 °C, calculated from the individual solubility in water and n-octanol, was determined to be (log Pow) 1.98.

Executive summary:

The n-octanol/water partition coefficient of FAT 36034/W was determined in a study conducted according to OECD Guideline 107 and EU Method A.8. Based on the solubility of FAT 36034/W in n-octanol and water, the partition coefficient was determined to be 1.98 (log Pow).

Description of key information

The n-octanol/water partition coefficient of FAT 36034/W was determined in a study conducted according to OECD Guideline 107 and EU Method A.8. Based on the solubility of FAT 36034/W in n-octanol and water, the partition coefficient was determined to be 1.98 (log Pow).

Key value for chemical safety assessment

Log Kow (Log Pow):

1.98

at the temperature of:

20 °C