Disodium 4,4'-methylenebis[3-hydroxy-2-naphthoate]

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 MAR 2013 - 20 JUN 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

European Commission Regulation (EC) No. 440/2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

no

GLP compliance:

no

Type of method:

flask method

Water solubility:

43 g/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

7

Preliminary Visual Estimation of the Water Solubility

Different amounts of the test item and water were treated with ultrasound or stirred at room temperature until the mixture appeared dissolved or the water solubility could be estimated to be below 10 mg/L.

Amount of test item in mg	Total volume in mL	Appearance of mixture
85.9	0.1	undissolved^1)
	0.5	undissolved^1)
	1.0	dissolved^1)

¹⁾: After adding the indicated amount of water, the solution was treated with ultrasound for 10 minutes.

According to the preliminary visual estimation the water solubility of the test item is above 86 g/L. Consequently the flask method was performed as main test.

Due to the high water solubility it had to be tested which amount of the test item could be stirred in a defined volume of water.

Amount of test item in g	Total volume in mL	Appearance of mixture
4.83	1	could not be stirred at room temperature
	2	could not be stirred at room temperature
	3	could not be stirred at room temperature
	3.5	could be stirred at room temperature
	5	could not be stirred at 20 °C
	6	could not be stirred at 20 °C
	6.5	could be stirred at 20 °C

The stirring test showed that a test item water mixture with a concentration of 743 g/L test item can be used for the flask method.

Flask method

Experiment	A	B	C	D (blank)
Amount of test Item (g)	9.69	9.66	9.65	--
Amount of destilled water (ml)	13	13	13	13
Stirring time at 30 °C (h)	24	48	72	72
pH at 23.2-23.5 °C	9.5	9.4	9.5	6.9
Aliquot of the flasks (mL)	0.1	0.1	0.1	0.1
Dilution (mL)	25	25	25	25
Aliquot of the diluted sample (mL)	1	1	1	1
Dilution (mL)	25	25	25	25
Dilution factor	6250	6250	6250	6250
Measured concentration (mg/L)	6.69/6.69	6.96/7.01	6.92/6.88	--/--
Mean concentration (mg/L)	6.69	6.98	6.90	--
Water solubility (g/L)^1)	41.8	43.7	43.1	--

¹⁾At the end of the equilibration time at 20 °C the test item water mixtures were no longer stirrable. It was assumed

that this had no effect on the final result as the stirring times of 24, 48 and 72 hours were reached.

The water solubility of the test item at 20 °C was determined to be 43 g/L (SD = 1 g/L).

The water solubility is calculated from the measured and unrounded concentration values and not from the rounded values given in Table before.

Conclusions:

The water solubility of the test item at 20 °C is 43 g/L.

Executive summary:

The water solubility of the test item was tested according to EU Method A.6 and OECD Guideline 105 in a non-GLP study. The water solubility c_s of the test item at a temperature of 20 °C was determined via HPLC with the flask method to be (without correction for the purity): c_s = 43 g/L (± 1 g/L).

Description of key information

The water solubility of the test item was tested according to EU Method A.6 and OECD Guideline 105 in a non-GLP study. The water solubility c_sof the test item at a temperature of 20 °C was determined via HPLC with the flask method to be (without correction for the purity): c_s= 43 g/L (± 1 g/L).

Key value for chemical safety assessment

Water solubility:

43 g/L

at the temperature of:

20 °C