Levomenol

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2017-04-06 to 2017-06-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

no

Type of method:

flask method

Key result

Water solubility:

22 mg/L

Incubation duration:

>= 24 - <= 72 h

Temp.:

20 °C

pH:

>= 5.9 - <= 6.2

Preliminary visual estimation of the water solubility

Amount of test item / mg	Total volume of dist. Water / mL	Appearance of mixture
12.8	100	Not dissolved
10.7	500	Not dissolved
4.7	500	Not dissolved

The preliminary visual experiments showed that the water solubility of the test item is < 10 mg/L. According to the preliminary visual estimation in the main test the water solubility should be determined with the column elution method. However a measurement with the aforementioned method showed a decreasing tendency. Therefore, the water solubility of the test item was determined by the flask method.

Flask method

After the equilibration time precipitate was observed in the flasks of the experiments excluding in the blank experiment. The water solubility was calculated from the measured and unrounded concentration values and not from the rounded values given in the table below:

Experiment	24 h experiment	48 h experiment	72 h experiment	Blank experiment (72 h)
Amount of test item / mg	36.2	34.7	34.7	-
Amount of demineralized water / mL	50	50	50	50
Stirring time at 30 °C / h	24	48	72	72
pH at 22 °C	2.9	6.2	6.1	6.1
Aliquot of the flasks /mL	0.1	0.1	0.1	0.1
1st dilution to volume / mL	5	5	5	5
Dilution factor	50	50	50	50
Measured concentration / mg/L	0.452 / 0.435	1.461 / 0.466	1.435 / 0.436	- / -
Mean concentration / mg/L	0.444	0.463	0.435	-
Water solubility / mg/L	22.2	23.2	21.8	-

The water solubility of the test item at 20 °C was determined to be 22 mg/L (± 0.7 mg/L).

Conclusions:

The water solubility of the test item at 20 °C was determined to be 22 mg/L (± 0.7 mg/L).

Executive summary:

The water solubility was determined according to OECD 105 and Regulation (EC) No. 440/2008 method A.6 using the shake flask method with HPLC analysis. About 34 - 36 mg test item were weighed into 100 mL stoppered Erlenmeyer flasks (nine parallels) according to the estimated solubility based on the Preliminary Test. After the addition of 50 mL demineralised water, the flasks were agitated at 30 °C. After 24, 48 and 72 hours, three of the vessels were removed and re-equilibrated at 20 °C for further 24 hours. An aliquot of the samples was taken and diluted 50 times before the analysis. The pH of each sample was recorded. The water solubility of the test substance was determined to be 22 ± 0.7 mg/L at 20 °C ± 1 °C (pH 5.9 - 6.1).

Description of key information

The water solubility of the test item was determined to be 22 mg/L.

Key value for chemical safety assessment

Water solubility:

22 mg/L

at the temperature of:

20 °C

Additional information

The water solubility was determined according to OECD 105 and Regulation (EC) No. 440/2008 method A.6 using the shake flask method with HPLC analysis (reference 4.8-1). About 34 - 36 mg test item were weighed into 100 mL stoppered Erlenmeyer flasks (nine parallels) according to the estimated solubility based on the Preliminary Test. After the addition of 50 mL demineralised water, the flasks were agitated at 30 °C. After 24, 48 and 72 hours, three of the vessels were removed and re-equilibrated at 20 °C for further 24 hours. An aliquot of the samples was taken and diluted 50 times before the analysis. The pH of each sample was recorded. The water solubility of the test substance was determined to be 22 ± 0.7 mg/L at 20 °C ± 1 °C (pH 5.9 - 6.1).