3,7-dimethyl-6-octenyl 2-methylcrotonate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 September to 12 October 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

The test design given in the guideline was modified to a slow-stirring design. Time and temperature conditions were based on the flask method.

GLP compliance:

yes (incl. QA statement)

Remarks:

Swiss Federal Office of Public Health

Type of method:

other: Slow-stirring design

Remarks:

Since the test item is a liquid with a density < 1, the OECD guideline was adapted to a slow-stirring design, in order to avoid formation of an emulsion. Time and temperature conditions were based on the flask method.

Key result

Water solubility:

0.385 mg/L

Temp.:

20 °C

pH:

7.02

Results

After a stirring time of 24 hours, 48 hours and 72 hours, respectively, at 30 °C, the samples were equilibrated for another 24 hours at 20 °C. Afterwards, a duplicate aliquot of the samples was taken through a cock at the bottom of the flask. The samples were analysed by HPLC with UV-detection. The results of the individual measurements are shown in the table below.

 

Results of the Water Solubility of [test item].The tabulated values represent rounded results, obtained by calculation using the exact raw data.

Sample No.	Stirring time at 30 °C [hours]	Measured Concentration [mg/L]	Mean Value [mg/L]	Overall Mean ± Std.Dev. [mg/L]
24-1	24	0.172	0.173
24-2	24	0.173
48-1	48	0.226	0.266
48-2	48	0.227
72-1	72	0.383	0.386	0.385 ± 0.016 (RSD: 4.1 %)
72-2	72	0.389
96-1	96	0.366	0.385
96-2	96	0.404
120-1	120	0.286	0.301
120-2	120	0.317
144-1	144	0.236	0.258
144-2	144	0.280

 

After 72 hours stirring, no plateau was achieved and the values were still increasing. The test was repeated using longer equilibration times.

After 96 hours the values were similar as for 72 hours. After 96 hours they started to decrease. Thus, the water was saturated after 72 hours.

 

Final results

In this study, the water solubility of the test item was determined using a slow-stirring experiment. The time / temperature conditions for the test were based on the OECD Guideline for the Testing of Chemicals, No. 105: Water Solubility, shake flask method.

The water solubility of the test item was found to be 0.385 ± 0.016 mg/L, at an average pH of 7.02.

The maximum solubility was achieved after 72 hours.

Conclusions:

A water solubility value of 0.385 ± 0.016 mg/L (at 20 °C, pH = 7.02) was determined for the test substance according to OECD 105.

Description of key information

Water solubility: 0.385 ± 0.016 mg/L at 20 °C, pH = 7.02 (OECD 105, Slow-stirring design)

Key value for chemical safety assessment

Water solubility:

0.385 mg/L

at the temperature of:

20 °C

Additional information

Since the test item is a liquid with a density < 1, the OECD guideline was adapted to a slow-stirring design, in order to avoid formation of an emulsion. Time and temperature conditions were based on the flask method.