1,4-bis[[4-(1,1-dimethylethyl)phenyl]amino]-5,8-dihydroxyanthraquinone

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

(1995)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

(2008)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Other quality assurance:

ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories)

Type of method:

column elution method

Key result

Water solubility:

< 3 µg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

ca. 7

 

Column 1 (12 mL/h)			Column 2 (24 ml L/h)
Fraction no.	pH value	Concentration	Fraction no.	pH value	Concentration
		[β] = g/L			[β] = g/L
11	7.3	< 3	1	6.4	< 3
12	7.4	< 3	2	6.3	< 3
13	7.1	< 3	3	6.5	< 3
14	7.3	< 3	4	6.6	< 3
15	7.0	< 3	5	6.7	< 3
16	7.2	< 3	6	6.7	< 3
17	7.5	< 3	7	6.5	< 3
18	6.7	< 3	8	6.5	< 3
19	7.4	< 3	9	6.6	< 3
20	6.8	< 3	10	6.6	< 3

Conclusions:

The water solubility determined by the column elution method at 20 °C was lower than 3 μg/L.

Executive summary:

The water solubility was determined using the method (OECD Guideline 105, EC Guideline A.6).

The water solubility of the test item, given by the sponsor, was lower than 10 mg/L. Therefore, the column elution method was chosen for the determination of the water solubility. For the main test the test item was eluted with water from a micro-column which is charged with silica gel, previously coated with an excess of the test item. At 20 °C twenty fractions were collected at a flow rate of 12 mL/h (column 1) and ten fractions at a flow rate of 24 mL/h (column 2). For each fraction 10 mL were collected. After dilution with acetonitrile the concentration of Solvent Green 28 in the solutions was determined by HPLC-analysis.

The water solubility determined by the column elution method at 20 °C was lower than 3 μg/L.

Description of key information

The water solubility determined by the column elution method at 20 °C was lower than 3 μg/L.

Key value for chemical safety assessment

Water solubility:

1.2 µg/L

at the temperature of:

20 °C

Additional information

The mean value determined with column 1 was 1.82 μg/L and the value determined with column 2 was 0.56 μg/L. For this reason, a mean value (1.19 μg/L) from these two values is used as a basis for assessing the chemical safety assessment.