(2-hydroxypropyl)trimethylammonium 2-ethylhexanoate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.6 (Water Solubility)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Principles of method if other than guideline:

The determination was carried out using a flask method designed to be compatible with Method A.6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 105 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

Batch number: meyers1.20160601
Purity: 96.5% active in water
Expiry date: 01 June 2017
Storage conditions: Room temperature in the dark

Key result

Water solubility:

ca. 10 vol%

Conc. based on:

test mat.

Temp.:

20 °C

pH:

> 6 - < 8

Water solubility:

ca. 20 vol%

Conc. based on:

test mat.

Temp.:

20 °C

pH:

> 6 - < 8

Details on results:

The test item was determined to be essentially miscible in water. Complete solubility was observed for aqueous solutions prepared at 5.0% w/w and all sample solutions evaluated at ≥25.0% w/w. Additional samples prepared within this region of immiscibility confirmed that the test item was not miscible with water within the concentration range of 7.49% w/w to 20.2% w/w. The water solubility of the test item in this region was therefore addressed analytically at two different initial nominal saturation loading rates of 10% w/w and 20% w/w. This evaluation indicated that the major components of the test item remained highly solubilized even when a visible excess was observed.
On completion of the re-equilibration period, the saturated samples prepared for analytical evaluation were straw colored, clear solutions with excess test item present on the surface of each sample. The solutions were centrifuged and filtered following removal from the static waterbath and exclusion of this excess undissolved test item was visually confirmed prior to diluting for analysis.
It was noted that the solution matrix blanks contained significant responses at the appropriate retention times of interest on analysis. This was attributed to the “sticky” nature of salts on analytical instrumentation. However this was considered not to impact on the accuracy of the quantification. This was since through the use of calibration curves, blank responses are automatically corrected for through displacement of the y axis intercept from the origin and also as all definitively quantified concentrations were obtained by interpolation from within the valid standard concentration range analyzed for the assay.

The test item was determined to be essentially miscible in water. Complete solubility was observed for aqueous solutions prepared at 5.0% w/w and all sample solutions evaluated at ≥25.0% w/w. Analysis of visibly saturated solutions prepared at two different initial nominal loading rates in the region of immiscibility resulted in data as summarized in the following table; indicating that the major components of the test item remained highly solubilized even when a visible excess was observed. All evaluations were performed at a test temperature of 20.0 ± 0.5 °C.

	Analyzed concentration (Equivalent test item concentration, g/L)
Nominal loading concentration (% w/w)	Quaternary amine cation	2-Ethylhexanoic acid content
10	105	89.8
20	222	214

Conclusions:

The test item was determined to be essentially miscible in water. Complete solubility was observed for aqueous solutions prepared at 5.0% w/w and all sample solutions evaluated at ≥25.0% w/w. Analysis of visibly saturated solutions prepared at two different initial nominal loading rates in the region of immiscibility resulted in data as summarized in the following table; indicating that the major components of the test item remained highly solubilized even when a visible excess was observed. All evaluations were performed at a test temperature of 20.0 ± 0.5 °C.

Executive summary:

Hydroxypropyl, N-2-, N,N,N-trimethylammonium 2-ethylhexanoate was determined to beessentially miscible in water. Complete solubility was observed for aqueous solutionsprepared at 5.0% w/w and all sample solutions evaluated at ≥25.0% w/w. Analysis of visiblysaturated solutions prepared at two different initial nominal loading rates in the region ofimmiscibility resulted in data as summarized in the following table; indicating that the majorcomponents of the test item remained highly solubilized even when a visible excess wasobserved. All evaluations were performed at a final test temperature of 20.0 ± 0.5 °C, using aflask method designed to be compatible with Method A.6 Water Solubility of CommissionRegulation (EC) No 440/2008 of 30 May 2008 and Method 105 of the OECD Guidelines forTesting of Chemicals, 27 July 1995.

Description of key information

The test item was determined to be essentially miscible in water. Complete solubility was observed for aqueous solutions prepared at 5.0% w/w and all sample solutions evaluated at ≥25.0% w/w. Analysis of visibly saturated solutions prepared at two different initial nominal loading rates in the region of immiscibility resulted in data as summarized in the following table; indicating that the major components of the test item remained highly solubilized even when a visible excess was observed. All evaluations were performed at a test temperature of 20.0 ± 0.5 °C.

Key value for chemical safety assessment

Water solubility:

200 g/L

at the temperature of:

20 °C