Heptanal, oligomeric reaction products with aniline

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 July 2016 - 03 November 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Deviations:

no

GLP compliance:

yes

Type of method:

column elution method

Water solubility:

< 0.36 mg/L

Conc. based on:

test mat.

Loading of aqueous phase:

12 mg/L

Incubation duration:

24 h

Temp.:

20 °C

pH:

>= 6.6 - <= 7.1

Water solubility:

< 1.4 mg/L

Conc. based on:

test mat.

Loading of aqueous phase:

120 mg/L

Incubation duration:

24 h

Temp.:

20 °C

pH:

>= 6.6 - <= 7.1

Key result

Water solubility:

< 0.16 mg/L

Conc. based on:

test mat.

Incubation duration:

24 h

Temp.:

20 °C

pH:

>= 6.6 - <= 7.1

Remarks on result:

other: value estimated on the loading rates of both 12 and 120mg/L

Details on results:

Results as obtained with the validated analytical method (transition m/z 380.3→ m/z 252.1, retention time approximately 1.5 min)

Preliminary test
The content of test item dissolved in the water sample was 2.32 mg/L.

Main study
In both main studies, analysed concentrations increased with stirring time. The establishment of a plateau was not indicated. During the hydrolysis study it was observed that the concentration of the test item determined based on the transition m/z 380.3 → m/z 252.1 at a retention time of approximately 1.5 min increased in course of the test. This was most probably due to the fact that the monitored component was formed by degradation of a higher molecular-weight component. During water-solubility testing the concentration of the monitored component increased with stirring time most probably due to degradation of a higher molecular weight component, too. Concentrations measured in the water-solubility samples were heightened by the degradation reaction and did not reflect the water solubility of the test item. It was, therefore, not possible to accurately determine the concentration of the test item with chemical analysis. Assuming that the part of component m/z 380.3 → m/z 252.1 at a retention time of approximately 1.5 min which was already present in the test item before degradation had already reached its equilibrium concentration after 24 hours, the water solubility was estimated as < 0.36 mg/L at a loading rate of 12 mg/L and < 1.4 mg/L at a loading rate of 120 mg/L.

At all stirring times and in both main studies, undissolved test item was observed in the glass vessels. Based on visual observation, the water solubility of the test item was < 12 mg/L at a loading rate of 12 mg/L and < 120 mg/L at a loading rate of 120 mg/L.

A small response was detected in the pre-treated sample from the blank water mixture after 72 and 193 hours of stirring. The concentration was 0.00033 mg/L and 0.00091 mg/L, respectively. Due to the small contribution, there was no impact on the water-solubility study.

Results estimated based on non-validated components
During the validation of the analytical method several signals turned out not sufficiently stable for accurate quantification of the test item. As degradation prohibited determining the water solubility based on transition m/z 380.3 → m/z 252.1 (retention time approximately 1.5 min), test-item concentrations were estimated based on the non-validated components (i.e. m/z 211.2 → m/z 193.2 with the retention time 2.4 min, m/z 380.3 → m/z 252.1 with the retention time 3.6 min and m/z 414.3 → m/z 296.3 with the retention times 2.3 and 2.4 min).

Calibration and sample solutions did not show signals for the components with a transition of m/z 211.2 → m/z 193.2 (retention time 2.4 min) and m/z 380.3 → m/z 252.1 (retention time 3.6 min). No conclusions could be drawn for these components.

Calibration solutions injected before and after the water solubility samples generated signals for the components m/z 414.3 → m/z 296.3 (retention time 2.3 and 2.4 min), while none of the water-solubility samples exhibited these responses. It was, therefore, estimated that at both loading rates the water solubility based on components with an m/z 414.3 → m/z 296.3 at a retention time of 2.3 and 2.4 min was smaller than 0.16 mg/L (i.e. the lowest concentration of a calibration standard, taking a dilution factor of 400 into account).

Main study at a loading of 12 mg/L - water solubility of the test item as obtained with the validated analytical method (transition m/z 380.3 → m/z 252.1, retention time approximately 1.5 min)

Stirring time [hours]	Analysed concentration [mg/L]	pH
24	0.362	6.6
48	0.407	6.8
72	0.493	6.9
145	0.578	6.8
169	0.658	6.9
193	0.775	6.8

 

Main study at a loading of 120 mg/L - water solubility of the test item as obtained with the validated analytical method (transition m/z 380.3 → m/z 252.1, retention time approximately 1.5 min)

Stirring time [hours]	Analysed concentration [mg/L]	pH
24	1.41	6.8
48	1.90	7.1
72	2.50	7.0
145	6.92	6.9
169	8.17	6.9
193	9.39	6.9

 

Conclusions:

Accordingly, it was not possible to accurately determine the water solubility of the test item with chemical analysis. Assuming that the part of the monitored component which was already present in the test item before degradation had reached its equilibrium concentration after 24 hours, the water solubility was estimated as < 0.36 mg/L at a loading rate of 12 mg/L and < 1.4 mg/L at a loading rate of 120 mg/L.

Based on analytical data for non-validated components(i.e. m/z 414.3 → m/z 296.3 at aretention time of 2.3 and 2.4 min) the water solubility was estimated as smaller than 0.16 mg/L both at a loading rate of 12 mg/L and 120 mg/L.

Executive summary:

The slow-stirring flask method was applied for the determination of the water solubility of Hepteen Base®. As the substance is a UVCB, the method was performed at two different loading rates.

 

With the validated analytical method (i.e. based on component m/z 380.3 → m/z 252.1 at are tention time of approximately 1.5) it was observed that the test-item concentrations increased with time. Maximum stirring time was 193 hours. The establishment of a plateau was not indicated. The observed increase in test-item concentration was most probably due to degradation of a (not-quantified) higher molecular weight component forming the component used for quantification. Accordingly, it was not possible to accurately determine the water solubility of the test item with chemical analysis. Assuming that the part of the monitored component which was already present in the test item before degradation had reached its equilibrium concentration after 24 hours, the water solubility was estimated as < 0.36 mg/L at a loading rate of 12 mg/L and < 1.4 mg/L at a loading rate of 120 mg/L.

 

Based on analytical data for non-validated components(i.e. m/z 414.3 → m/z 296.3 at aretention time of 2.3 and 2.4 min) the water solubility was estimated as smaller than 0.16 mg/L both at a loading rate of 12 mg/L and 120 mg/L.

 

The pH of the aqueous samples was 6.6 - 7.1.

Description of key information

Assuming that the part of the monitored component which was already present in the test item before degradation had reached its equilibrium concentration after 24 hours, the water solubility was estimated as < 0.36 mg/L at a loading rate of 12 mg/L and < 1.4 mg/L at a loading rate of 120 mg/L.

With the validated analytical method (i.e. based on component m/z 380.3 → m/z 252.1 at a retention time of approximately 1.5) it was observed that the test-item concentrations increased with time. Maximum stirring time was 193 hours. The establishment of a plateau was not indicated. The observed increase in test-item concentration was most probably due to degradation of a (not-quantified) higher molecular weight component forming the component used for quantification. Accordingly, it was not possible to accurately determine the water solubility of the test item with chemical analysis. Assuming that the part of the monitored component which was already present in the test item before degradation had reached its equilibrium concentration after 24 hours, the water solubility was estimated as < 0.36 mg/L at a loading rate of 12 mg/L and < 1.4 mg/L at a loading rate of 120 mg/L.

Based on analytical data for non-validated components (i.e. m/z 414.3 →  m/z 296.3 at a retention time of 2.3 and 2.4 min) the water solubility was estimated as smaller than 0.4 µg/L both at a loading rate of 12 mg/L and 120 mg/L.

The pH of the aqueous samples was 6.6 - 7.1.

 

Key value for chemical safety assessment

Water solubility:

0.16 mg/L

at the temperature of:

20 °C

Additional information

A study using UPLC / MS was conducted to determine the water solubility of Hepteen Base ®. The experiment was conducted in accordance with the following guidelines in a GLP accredited laboratory.

European Community (EC), EC no. 260/2014, Part A: Methods for the Determination of Physico-Chemical Properties, Guideline A.6: “Water Solubility”, Official Journal of the European Union no. L81, March 19, 2014.

Organization for Economic Co-operation and Development (OECD), OECD Guidelines for the Testing of Chemicals no. 105: "Water Solubility", July 27, 1995.

United States Environmental Protection Agency (EPA), Product Properties Test Guidelines no. OPPTS 830.7840: "Water Solubility: Column Elution Method; Shake Flask Method", March 1998.