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Physical & Chemical properties

Water solubility

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Reference
Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
19 Aug 2017 to 22 Sep 2017
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
according to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes
Type of method:
flask method
Specific details on test material used for the study:
- Lot number: 70518-X
- Appearance: Yellowish Liquid
- Expiration date: 18-08-2017
- Purity: 99.2 %
Remarks on result:
not determinable
Remarks:
test substance is unstable in water. Therefore, measurement of the water solubility is not possible.
Details on results:
The mean measured concentration of the test substance decreased from 21.416 g/L at t=24h to 11.223 g/L at t=72h. As the test substance is unstable in contact with water (hydrolisation and polymerisation), the test results are considered unreliable. For an overview of and additional comments on the results of the study, see 'Any other information on results incl. tables'.

Table: Analytical Determinations

Flask No.

Dil. Factor

pH

Peak Area 1

Peak Area 2

Mean concentration (g/L)

1

50

N/A

5499953

5498623

21.416

2

50

N/A

4293839

4305348

16.745

3

50

N/A

2884875

2877626

11.223

ADDITIONAL COMMENTS

- Preliminary estimation: It was difficult to accurately determine a preliminary estimation of the solubility of the product, due to the limitations in seeing droplets of a clear liquid in water. A visual estimated solubility of 2.5 mg/L was observed. Consequently a saturated solution was prepared and filtered through a 0.1 μm syringe filter to give a clear liquid. This solution was analysed by HPLC using a single point calibration to give a concentration of approximately 40 mg/mL. This was noticeably greater than the visual estimation of 2.5 mg/mL. The saturated solution was prepared using a concentration of 4.1 g/100 mL. At this concentration the majority of the test material did not dissolve.

- Observations during preparation: The three day saturated solution was prepared by transferring 4.1 g of the test material into a 250 mL screw topped conical flask and adding 100 mL of water. The flask was shaken at 150 rpm. After 24 and 48 hours additional flasks were added to the shaker. After 72 hours from the start of the shaking all three samples were allowed to equilibrate at 20°C for 24 hours prior to analysis. It was noted that the clear pale yellow liquid sample turned to opaque yellow droplets after 24 hours. After 48 and 72 hours of shaking the solution became slightly cloudy.

- Stability of the test substance: From the results above it can be seen that the solubility of the test material appears to decrease with time. As the area of the product peak seen the HPLC analysis decreases over the three day period, it can be seen that some early eluting peaks correspondingly increase over this period. The implication being that the test substance is not stable to the test conditions used. A fresh sample was taken from the Day 1 shaken solution. This sample was centrifuged, filtered and reanalysed 4 days after the original analysis. The concentration of the test substance peak had reduced from approximately 21.4 g/L to 12.8 g/L. This result further supports the suggestion that the product is not stable in the presence of water under the test conditions used. Due to the hydrolysis and polymerisation of the test substance when being in contact with water, and the unknown kinetics behind these reactions, it can be determined that the test substance is unstable in water and a measurement of water solubility is therefore technically not feasible.

Description of key information

Determination of the water solubility of the test substance was not possible in a study according to OECD TG 105. Due to the hydrolysis and polymerisation of the test substance when being in contact with water, and the unknown kinetics behind these reactions, it can be determined that the test substance is unstable in water and a measurement of water solubility is therefore technically not feasible.

Key value for chemical safety assessment

Additional information