Trisodium bis[4-[4,5-dihydro-4-[(2-hydroxy-5-nitrophenyl)azo]-3-methyl-5-oxo-1H-pyrazol-1-yl]benzene-1-sulphonato(3-)]cobaltate(3-)

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From September 09th to 14th, 2019

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

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

2014

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Version / remarks:

1998

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Water solubility:

18.6 g/L

Conc. based on:

test mat.

Remarks:

95 % confidence interval

Incubation duration:

24 h

Temp.:

20 °C

pH:

ca. 5.38

Water solubility:

17.7 g/L

Conc. based on:

test mat.

Remarks:

95 % confidence interval

Incubation duration:

48 h

Temp.:

20 °C

pH:

>= 5.38 - <= 5.39

Water solubility:

17.4 g/L

Conc. based on:

test mat.

Remarks:

95 % confidence interval

Incubation duration:

72 h

Temp.:

20 °C

pH:

>= 5.37 - <= 5.38

Details on results:

-Calibration: the calibration solutions were prepared in 0.05-10 µg/ml range. The calibration samples were analysed by HPLC-UV-VIS with three replicate injections from each. Concentration of tet item was calculated with the help of the calibration equation.

-Results of water solubility test: result of the test and measured concentration are summarised in a table. The measured concentrations are constant within ±15 % and thus within the range required by the guidelines.

-There was no deviation to the study plan.

-There was no amendment to the study plan.

Results of determination of test item concentrations

Sampling time	Measured concentration of test item (g/l)			Measured pH
	Test vessels	Mean with the 95 % confidence intervals
After 24h	18.5	18.6 ± 4.1		5.38
	20.3			5.38
	17			5.38
After 48h	17.4	17.7 ± 1.0		5.39
	18.2			5.38
	17.5			5.38
After 72h	17.1	17.4 ± 0.7		5.38
	17.7			5.38
	17.5			5.37
Solubility of the test item (g/l)		17.9 ± 1.6	-
RSD %		4	-
pH of Ultra-pure water		-	6.69

Conclusions:

In conclusion the water solubility of test item was determined to be 17.9 ± 1.6 g/l (95 % confidence interval) at 20 ± 1 °C and pH ca. 5.4, using the shake-flask method for the performance.

Executive summary:

The objective of this study was to determine the solubility of the test item in water at 20 ± 1 °C. A preliminary test for the water solubility was carried out as a range finding test for the decision whether the column elution method or the flask method has to be used for the performance of the main test.

In the course of this study the water solubility of test item was determined using the shake-flask method for the performance of the main test. Water solubility was 17.9 ± 1.6 g/l (95 % confidence interval) at 20 °C and pH 5.4.

Description of key information

17.9 ± 1.6 g/l (95 % confidence interval) at 20 ± 1 °C and pH ca. 5.4, using the shake-flask method for the performance.

Key value for chemical safety assessment

Water solubility:

17.9 g/L

at the temperature of:

20 °C

Additional information

OECD guideline 105 - shake-flask method.