p-[4,5-dihydro-4-[[2-methoxy-5-methyl-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulphonic acid, sodium salt

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 19, 2016 - June 03, 2016

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:

no

Type of method:

flask method

Key result

Water solubility:

366 g/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

ca. 5

 Individual results

Preliminary visual estimation of the water solubility

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 15 minutes and visually checked for any undissolved particles.

Table4: Results of the preliminary visual estimation of the water solubility

Amount of test item / mg		Added volume of dist. water / mL		Total volume / mL		Appearance of mixture
111.0		0.1		0.1		not dissolved
		0.4		0.5		dissolved

The preliminary visual experiments showed that the water solubility of the test item is > 222 g/L and < 1110 g/L. According to the preliminary visual estimation in the main test the water solubility was determined by the flask method.

Experiments followed to check whether the concentrated test item solution mixtures can be stirred. The results are compiled in Table5.

Table5: Results of the stirrer experiments of the aqueous mixtures

Amount of test item / g		Added volume of dist. water / mL		Total volume / mL		Appearance of mixture
5.3951		2		2		Could not be stirred.
		1		3		Could not be stirred.
		1		4		Could not be stirred.
		0.5		4.5		Could not be stirred.
		0.5		5		Could not be stirred.
		0.5		5.5		Could be stirred.

Thus a concentration of approx. 1 g test item / mL water was defined for the main test.

Flask method

The flask method was performed as described. The data for the evaluation are given in Table6. The water solubility was calculated from the measured and unrounded concentration values and not from the rounded values given in Table6.

Table6: 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	10.2957	10.0526	10.1676	--
Amount of demineralized water / mL	10	10	10	10
Stirring time at 30 °C / h	24	48	72	72
pH at 23 - 24 °C	5.0	4.9	4.8	5.3
Aliquot of the flasks / mL	0.1	0.1	0.1	0.1
1^stDilution to volume / mL	10	10	10	10
Aliquot of the flasks / mL	0.02	0.02	0.02	0.02
2^ndDilution to volume / mL	1	1	1	1
Dilution factor	5000	5000	5000	5000
Measured concentration / mg/L	77.7 / 77.6	68.1 / 68.1	73.5 / 73.6	-- / --
Mean concentration / mg/L	77.6	68.1	73.6	--
Water solubility / g/L	388	340	368	--

The water solubility of the test item at 20 °C was determined to be366 g/L (± 24 g/L).

Executive summary:

The water solubility c_Sof the test item Reactive Yellow 15 at a temperature of 20 °C was determined to be:

                                                                 c_S=366 g/L (± 24 g/L)

The purity of the test item was not taken into account. The sample was tested as received.

Description of key information

 The water solubility of the test item Reactive Yellow 15 at a temperature of 20 °C was determined to be 366 g/L without correction for purity 

Key value for chemical safety assessment

Water solubility:

366 g/L

at the temperature of:

20 °C

Additional information

The water solubility c_Sof the test itemReactive Yellow 15 at a temperature of 20 °C was determined to be:

                                                                 c_S=366 g/L (± 24 g/L)

The purity of the test item was not taken into account. The sample was tested as received.