2-[[4-[ethyl(2-hydroxyethyl)amino]phenyl]azo]-6-methoxy-3-methylbenzothiazolium methyl sulphate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

For justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Water solubility:

46 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

238 g/L

Incubation duration:

4 d

Temp.:

20 °C

pH:

3

Conclusions:

The water solubility of the test item a temperature of 20 °C was determined according to the flask method to be:         cS= 46 g/L(± 3 g/L)

Executive summary:

The water solubility of the test subtance was deteremined according to OECD 105 using preliminary visual estimation and flask method. For the preliminary visual estimation of the water solubility a mixture of water and test item ist prepared and assessed visually.

The approximate water solubility of the test item, resulting from the preliminary test, indicates which of the two methods (column elution method < 10 g/L; flask method > 10 g/L). Additionally, the results of the preliminary test provide information regarding the appropriate amount of test item to be used in the main test. As the preliminary visual estimation indicated a solubility above 10 g/L, the flask method was performed.

For the flask method , the quantity of test item necessary to saturate the desired volume of water is estimated from the preliminary test and about five times that quantity is weighed into each of three glass vessels fitted with glass stoppers. The batches including a blank flask without test item are stirred for different times at 30 °C (24 h experiment, 48 h experiment, 72 h experiment) in tightly closed flasks. After equilibration (further stirring for 24 h at 20 °C) the suspensions are taken and prepared for the analytical determination via HPLC. The pH values of the saturated solutions are determined.

The water solubility c_Sof the test item at a temperature of 20 °C was determined to be:         c_S= 46 g/L(± 3 g/L)

This information is used in a read-across approach in the assessment of the target substance.

For justification of read-across please refer to the attached read-across report (see IUCLID section 13).

Description of key information

The water solubility of the test substance was determined according to OECD 105 using preliminary visual estimation and flask method as the preliminary estimation indicated a solubility above 10 g/L. For the flask method, three batches of a measured amount of the test item and deionized water are stirred for 24, 48, and 72 hours at 30°C followed by equilibration (further stirring for 24 h at 20°C).After preparation the concentration of the test item was determined using HPLC.

The water solubility c_Sof the test item at a temperature of 20 °C was determined to be:         c_S= 46 g/L (± 3 g/L)

This information is used in a read-across approach in the assessment of the target substance.

For justification of read-across please refer to the attached read-across report (see IUCLID section 13).

Key value for chemical safety assessment

Water solubility:

46 g/L

at the temperature of:

20 °C