Alcohols, C12-13, branched and linear, ethoxylated, sulfates, sodium salts

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 - 28 Oct 2014

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

yes

Remarks:

visual assessment; no data about pH

Principles of method if other than guideline:

Company standard operating procedure reference: CTL SOP No. 406B.

GLP compliance:

yes

Remarks:

The Department of Health of the Government of the United Kingdom

Type of method:

flask method

Key result

Water solubility:

> 300 g/L

Temp.:

30 °C

Remarks on result:

other: pH not determined

Preliminary test:

32010 mg dissolved in 80 mLwater gives estimated solubility of 200-1000 g/L. Analysis method: shake flask. Flask method is chosen for the main test.

Main test:

16 Oct:: 1 mg/mL solution in water was prepared and analysed by HPLC. The chromatogram showed a single peak with significant tailing. It was not thought that an HPLC method could be developed in order to give accurate sample concentration values. The product had limited UV absorbance and could only be detected at low UV wavelengths.

20 Oct.: 8.07 g of Na C12-13 AES was added to 80 mL water and placed on a shaker. After being shaken for 1 hour at 30 °C, the sample was fully dissolved. A second sample was prepared 24.06 g of Na C12-13 AES was added to 80 mL water and placed on a shaker. After being shaken for approximately 18 hours at 30 °C, the sample was fully dissolved to give a clear colourless slightly viscous liquid.

21. Oct: A third sample was prepared 32.01 g of Na C12-13 AES was added to 80 mL water and placed on a shaker. After being shaken for approximately 24 hours at 30 °C, the sample was fully dissolved to give a clear colourless noticeably viscous liquid.

22. Oct: A fourth sample was prepared 43.89 g of Na C12-13 AES was added to 48 mL water and placed on a shaker.

23. Oct: After being shaken for approximately 18 hours at 30°C, the fourth sample was a mixture of un-dissolved material and a viscous liquid. Upon stirring the mixture the sample formed a paste. A portion of the 8, 24 and 32 g samples was filtered through a 0.1 μm filter and diluted by a factor of 100:1 with water (HPLC grade). The UV spectrums of these samples were compared against the corresponding unfiltered samples (also diluted by a factor of 100:1). No significant differences in the corresponding UV spectra were noticed. The assumption being that Na C12-13 AES (a known surfactant) does not form micelles or the micelles formed are smaller than 0.1 μm.

24. Oct: An additional 18 mL of water was added to the fourth sample and shaken for a further 24 hours. The sample, with the additional water, remained as a mixture of an opaque gel and a clear very viscous gel / liquid.

Table of results:

Sample no.	Wt sample [g]	Wt water added [g]	Sample conc. [wt/wt]	Time taken to dissolve when shaken at 30 °C [h]
1	8.07	80	9.2	1
2	24.06	80	23.1	18
3	32.01	80	28.6	24
4	43.89	48	47.8	Paste formed
4+	43.89	66	40	Gel formed*)

*) After additional 24 hours the sample was a mixture of an opaque gel and a clear viscous gel/liquid.

At a concentration of approx. 10 g/L there was a noticeable change in the viscosity of the solution. The substance remained as a mobile solution until >300 g/L until gelling was observed from 400 g/L onwards.

Description of key information

Water solubility: ca.  300 g/L at 30 °C. (EU A.6, flask method)

Additional information

The substance remained as a mobile solution until gelling was observed from 400 g/L onwards.