Sodium 2-(1-carboxylatoethoxy)-1-methyl-2-oxoethyl laurate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-06-22 to 2018-09-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

no

Type of method:

flask method

Specific details on test material used for the study:

- Test item: Esterlac SLL
- CAS No.: 13557-75-0
- Molecular weight: 294.37 g/mol
- Sum formula: C18H31NaO6
- Identity: 64.2% aicd value, 194 saponification number
- Physical state: Light yellow paste
- Storage: 10 °C - 30 °C

Key result

Water solubility:

> 114 g/L

Conc. based on:

test mat. (dissolved fraction)

Incubation duration:

>= 24 - <= 72 h

Temp.:

20 °C

pH:

6.8

Preliminary test

In a stepwise procedure, increasing volumes of demineralised water were added at room temperatue to a defined amount of the test item. After each addition the mixture was treated with ultrasound for 10 minutes and visually checked for any undissolved particles (Table 1). The preliminary test showed that the water solubility of the test item is > 10 mg/L. Accordingly, the water solubility was determined by the flask method in the main test.

Table 1: Results of the preliminary test

Amount of test item / mg	Added volume of demineralised water / mL	Total volume of demineralised water / mL	Appearance of mixture
106.1	0.1	0.1	Not dissolved
	0.4	0.5	Not dissolved
	0.5	1.0	Not dissolved
	1	2	Not dissolved
	8	10	Dissolved (slightly turbid)

Flask method

During stirring the solutions with the test item showed the formation of foam. After the equilibration the solutions were extremely viscous but mostly clear and no precipitate was observed. The viscous masses were centrifuged and filtered. The following preparation for the analysis needed several days (time needed for the solution to settle in a measuring cylinder for dilution). Due to the high viscosity the pH was measured after the first dilution step from approximately 2 mL (due to the high viscosity it was not possible to use exactly 2 mL, therefore the present test mixture was used (2.0 mL for 24 h experiment, 2.8 mL for 48 h experiment, 1.6 mL for 72 h experiment)) to 10.0 mL with demineralised water (this first dilution step resulted in different dilution factors for each experiment). After the first dilution step the solutions with the test item were turbid (the turbidity had no influence on the final result). Results of the water solubility experiments with the test item are summarised in Table 2.

Table 2: Water solubility experiments of the test item

Experiment	24 h	48 h	72 h	Blank experiment (72 h)
Amount of test item / g	2.505	2.517	2.513	-
Added amount of demineralised water for the test solutions / mL	10	10	10	10
Stirring time at 30 °C / h	24	48	72	72
pH at ambient temperature	6.8	6.8	6.8	5.7
Dilution factor	5556	3571	3125	1000
Measured concentration* / mg/L	19.62 / 19.84	34.80 / 35.64	33.89 / 33.69	- / -
Mean concentration / mg/L	19.73	35.22	33.79	-
Water solubility / g/L	109.6	125.8	105.6	-

*under consideration of an estimated carbon content of 61.2 % (molecular mass 294.4 g/mol, containing 15 carbon atoms) for the test item and without correction of the purity.

The water solubility of the test item at 20 °C was determined to be > 114 g/L (the water solubility could have been influenced by self-organisation of the test item).

The used analytical method (TOC) only detects any carbon present in the test solutions and is therefore not specific to the target molecule. Furthermore, the determination of the water solubility of the test item was associated with uncertainties (e.g. foaming, equilibrated solution very viscous, time needed for solution settling). Nevertheless, the experimental results on the solubility of the test item in water are considered adequate and therefore constitute the best possible approximation to the behaviour of the test item in water.

Conclusions:

The water solubility of the test item at 20 °C was determined to be > 114 g/L (pH 6.8).

Executive summary:

The water solubility of the test item at 20 °C was determined according to OECD 105 using the flask method. The water solubility was determined to be > 114 g/L (pH 6.8).

Description of key information

The water solubility of the test item at 20 °C was determined according to OECD 105 using the flask method. The water solubility was determined to be > 114 g/L (pH 6.8).

Key value for chemical safety assessment

Water solubility:

114 g/L

at the temperature of:

20 °C