Trisodium 5-[[5-[[4-chloro-6-[(3-sulphonatophenyl)amino]-1,3,5-triazin-2-yl]amino]-2-sulphonatophenyl]azo]-1-ethyl-1,2-dihydro-6-hydroxy-4-methyl-2-oxopyridine-3-methanesulphonate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 06, 2017 - February 02, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

refer to 'Any other information on materials and methods' section.

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

yes

Remarks:

refer to 'Any other information on materials and methods' section.

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Deviations:

yes

Remarks:

refer to 'Any other information on materials and methods' section.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: RY-95-001
- Expiration date of the lot/batch: July 1, 2022

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature (20 +/- 5°C) in the dark

Key result

Water solubility:

338.3 g/L

Conc. based on:

test mat. (dissolved fraction)

Loading of aqueous phase:

625 g/L

Incubation duration:

96 h

Temp.:

20 °C

pH:

6.3

Preliminary test:

A preliminary test for the water solubility was carried out. The solubility of the test item was estimated by visual solubility testing described in the guidelines. About 100 mg of the test item were filled in a glass-stoppered 10 mL glass tube and increasing volumes of water were added. After each addition the mixture was shaken vigorously for about 10 minutes and afterwards checked for any undissolved parts of the test item.

The solubility of the test item in water was estimated to be about 500 g/L in the preliminary test.

Based on the guideline the shake flask method has to be used for the test performance for substances with solubility > 10 mg/L.

Flask method:

A first approach was conducted with 10 ml of water added to 25 g test item (five-fold concentration derived from the pre-test). After the incubation at 30°C was completed, the test item showed a hard glass-like surface with lots of unwetted test item below. The added water was completely soaked in, no liquid remained. A saturated solution cannot be separated.

The second approach was conducted with 8 ml of water added to 5 g of test item.

After the incubation at 30°C, two of the samples (24h-incubation, Sample 2 and 48h-incubation Sample 1) were completely dissolved; in all of the other samples a saturated solution with remaining visible test item resulted. The saturation at 20°C was prolonged from 24 to 96 hours to ensure total precipitation. Here, all samples showed significant amounts of remaining test item. The solutions were filtered and the concentration of the test item was determined in the clear aqueous phase (saturated solution) separated.

Additionally, a repetition of the filtration and analytical measurement has been conducted because in the two samples completely dissolved after the 30°C-incubation, ongoing precipitation was visible.

Conclusions:

The water solubility of Reactive Yellow 95 (meta) was determined to be 338.3 g/L at 20°C using the flask method.

Executive summary:

The water solubility of the test item was determined using the shake flask method. The saturation mass concentrations of the test item were determined using HPLC.

The results showed no tendency to increase time-dependent; therefore the study is considered to be valid.

Corresponding to the analyses the water solubility was determined to be 338.3 g/L at 20 °C.

The test item showed extraordinary behaviour. There is only a small window between total solubility and complete absorption of the added liquid.

Two of the six samples seemed to show a super-saturation phenomenon. After the prolonged saturation time at 20°C, additional test item precipitated. These samples were not incorporated in the calculation.

Description of key information

The water solubility of Reactive Yellow 95 (meta) was determined to be 338.3 g/L at 20°C using the flask method.

Key value for chemical safety assessment

Water solubility:

338 g/L

at the temperature of:

20 °C

Additional information

The water solubility of the test item was determined using the shake flask method. The saturation mass concentrations of the test item were determined using HPLC.

The results showed no tendency to increase time-dependent; therefore the study is considered to be valid.

Corresponding to the analyses the water solubility was determined to be 338.3 g/L at 20 °C.

The test item showed extraordinary behaviour. There is only a small window between total solubility and complete absorption of the added liquid.

Two of the six samples seemed to show a super-saturation phenomenon. After the prolonged saturation time at 20°C, additional test item precipitated. These samples were not incorporated in the calculation.