Tetrasodium 7,7'-(carbonyldiimino)bis[4-hydroxy-3-[(2-methyl-4-sulphonatophenyl)azo]naphthalene-2-sulphonate]

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June from 18th to 22nd, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

adopted July 27, 1995

Deviations:

yes

Remarks:

for determination of water solubility about two times the quantity of test item necessary to saturate the desired volume of water (estimated by the preliminary test) was applied. The deviation does not impact the reliability of test results.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Water solubility:

191 g/L

Conc. based on:

test mat.

Incubation duration:

24 - 72 h

Temp.:

20 °C

pH:

8.2

Details on results:

PRELIMINARY TEST
The water solubility of the test item was estimated to be ca 339 g/l in a preliminary test and therefore the shake-flask method was used in the main test.

MAIN TEST
The water solubility of the test item was determined to be 191 ± 9.1 g/l (95 % confidence interval) at 20 ± 1 °C and pH ca 8.2, using the shake-flask method for the performance.
The measured concentrations are constant within ± 15 % and thus within the range required by the guidelines.

Sampling time	Measured concentration of test item (g/l)			Measured pH
	Test vessels	Mean with the 95 % confidence intervals
After 24h	195	191 ± 9.0		8.21
	192			8.24
	187			8.23
After 48h	182	188 ± 12.7		8.23
	192			8.24
	188			8.25
After 72h	195	195 ± 0.9		8.22
	195			8.21
	195			8.25
Solubility of the test item (g/l)		191 ± 9.1	-
RSD%		2	-
pH of ultra-pure water		-	6.9

Conclusions:

191 ± 9.1 g/l at 20 ± 1 °C and pH ca 8.2

Executive summary:

The water solubility of the test item was determined in accordance with the method and procedures outlined into the OECD guideline 105. A preliminary test for solubility was carried out to choose between column elution method or flask method for the performance of the main test. The water solubility of the test item was estimated to be ca 339 g/l in a preliminary test and therefore the shake-flask method was used in the main test.

The concentration of the test item was determined by HPLC-UV/Vis validate method. The pH of each sample was recorded.

The water solubility of the test item was determined to be 191 ± 9.1 g/l (95 % confidence interval) at 20 ± 1 °C and pH ca 8.2, using the shake-flask method for the performance.  

Measured concentrations are constant within ± 15 % and thus within the range required by the guidelines.

Conclusion

191 ± 9.1 g/l at 20 ± 1 °C and pH ca 8.2

Description of key information

191 ± 9.1 g/l at 20 ± 1 °C and pH ca 8.2

Key value for chemical safety assessment

Water solubility:

191 g/L

at the temperature of:

20 °C

Additional information

OECD 105 - Flask Method