Reaction products of diazotised 2-amino-5-{[2-(sulfooxy)ethyl]sulfonyl}benzenesulfonic acid coupled with 4-amino-5-hydroxynaphthalene-2,7-disulfonic acid under acidic conditions, further coupled with diazotised reaction products of 2,4,6-trifluoro-1,3,5-triazine with 2-[(2-anilinoethyl)sulfonyl]ethyl hydrogen sulfate and 2,4-diaminobenzenesulfonic acid (1:1:1) under alkaline conditions, potassium sodium salts

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 05, 2018 - October 15, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

128.5 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

637 g/L

Incubation duration:

24 h

Temp.:

20 °C

pH:

5.8

Remarks on result:

other: calculated for the UVCB

Key result

Water solubility:

81.1 g/L

Conc. based on:

other: main constituent 1

Loading of aqueous phase:

637 g/L

Incubation duration:

24 h

Temp.:

30 °C

pH:

5.8

Key result

Water solubility:

47.4 g/L

Conc. based on:

other: main constituent 2

Loading of aqueous phase:

637 g/L

Incubation duration:

24 h

Temp.:

30 °C

pH:

5.8

Water solubility:

67.8 g/L

Conc. based on:

other: main constituent 1

Loading of aqueous phase:

632 g/L

Incubation duration:

48 h

Temp.:

30 °C

pH:

5.9

Water solubility:

37 g/L

Conc. based on:

other: main constituent 2

Loading of aqueous phase:

632 g/L

Incubation duration:

48 h

Temp.:

30 °C

pH:

5.9

Water solubility:

69.9 g/L

Conc. based on:

other: main constituent 1

Loading of aqueous phase:

640 g/L

Incubation duration:

72 h

Temp.:

30 °C

pH:

6

Water solubility:

36.6 g/L

Conc. based on:

other: main constituent 2

Loading of aqueous phase:

640 g/L

Incubation duration:

72 h

Temp.:

30 °C

pH:

6

Preliminary test

In a stepwise procedure, increasing volumes of demineralized water were added at room temperature to a defined amount of the test item. After each addition of an amount of water the mixture was treated with ultrasound for 10 minutes and visually checked for any undissolved particles.

Table6: Results of the preliminary test

Amount of test item / mg	Added volume of demineralized water / mL	Total volume of demineralized water / mL	Appearance of mixture
91.1	0.1	0.1	not dissolved
	0.4	0.5	dissolved, dark blue solution, no solid was visually detectable.

The preliminary test showed that the water solubility of the test item is > 10 mg/L. According to the preliminary test the water solubility was determined by the flask method in the main test. As the water solubility determined in the preliminary test was very high (>182 g/L), an additional stirring test was performed to determine the highest amount of test item that can still be stirred sufficiently in a mixture with water.

 

Table7: Results of the stirring test

Amount of test item / g	Added volume of demin. water / mL	Total volume / mL	Observation
4.9958	5	5	could not be stirred
	1	6	could not be stirred
	1	7	could not be stirred
	1	8	could be stirred*

Remark: *):solids could not be detected visually, as the mixture was dark blue.

According to the stirring test mixtures with a concentration of approx. 625 g/L test item in demineralized water were used in the main test.

Flask method

The flask method was performed as described above. The data for the evaluation are given in Table8. After the equilibration time precipitate was observed in the flasks of the experiments excluding in the blank experiment.The water solubility was calculated from the measured and unrounded concentration values and not from the rounded values given in Table8.

Table8: Water solubility experiments of the test item

Experiment	24 h experiment	48 h experiment	72 h experiment	Blank experiment (72 h)
Amount of test item / g	5.0952	5.0545	5.1187	--
Amount of demineralized water / mL	8	8	8	8
Stirring time at 30 °C / h	24	48	72	72
pH* at ambient temperature	5.8	5.9	6.0	6.6
Dilution factor	10,000	10,000	10,000	10,000
Results for main constituent 1
Measured concentration / mg/L	8.11 / 8.10	6.77 / 6.80	6.99 / 6.99	-- / --
Mean concentration / mg/L	8.11	6.78	6.99	--
Water solubility / g/L	81.1	67.8	69.9	--
Results for main constituent 2
Measured concentration / mg/L	4.73 / 4.75	3.70 / 3.69	3.65 / 3.66	-- / --
Mean concentration / mg/L	4.74	3.70	3.66	--
Water solubility / g/L	47.4	37.0	36.6	--

Remark: *) The pH was measured after the first dilution step due to the available small volume

    of the undiluted centrifuged and filtered samples.

The water solubility of the test item showed a falling tendency for both main constituents 1 and 2 for the 24h and 48h experiment. As the test item could undergo hydrolysis during treatment with water, as a conservative approach the highest measured value of the water solubility was stated.

 

Thus the water solubility of the test item at 20 °C was determined to be

81.1 g/L for main constituent 1 and

47.4 g/L for main constituent 2,

resulting in a total water solubility of

128.5 g/L main constituent 1 & 2.

Executive summary:

The water solubility c_S of the test item, which consisted of two main constituents, at a temperature of 20 °C was determined according to the flask method. It was found to be:

c_S = 81.1 g/L for main constituent 1 and

c_S = 47.4 g/L for main constituent 2,

resulting in a total water solubility of

c_S = 128.5 g/L main constituent 1 & 2.

Description of key information

The water solubility c_S of the test item, which consisted of two main constituents, at a temperature of 20 °C was determined according to the flask method. It was found to be:

c_S = 81.1 g/L for main constituent 1 and

c_S = 47.4 g/L for main constituent 2,

resulting in a total water solubility of

c_S = 128.5 g/L main constituent 1 & 2.

Key value for chemical safety assessment

Water solubility:

128.5 g/L

at the temperature of:

20 °C