2,5-di-tert-pentylhydroquinone

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04 August 2016 to 04 October 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

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.

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Version / remarks:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Specific details on test material used for the study:

No further details specified in the study report

Key result

Water solubility:

< 0.2 µg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

>= 6.3 - <= 6.4

Details on results:

Test item was detected at either flow rate only below the concentration of the lowest calibration standard. The analysed concentrations are, therefore, reported as below the lowest calibration standard, multiplied by the dilution factor.
Test item was detected when the loaded column material was analysed. This proved that the column was not depleted when the water solubility samples were taken.
The turbidity of the eluates was < 0.2 NTU. According to this, no undissolved particles were detected in the eluates.
Test item was detected below the concentration of the lowest calibration standard from the blank column in samples collected at a flow rate of 24 mL/h. At a rate of 12 mL/h no test item was detected in the samples from the blank column.

 

Main Study – water solubility of the test item

Flow rate [mL/h]	Sample no.	Concentration analysed					pH
		Individual [μg/L]	Mean^1 [μg/L]	CV [%]	Mean^1 [μg/L]	MD [%]
24	1 2 3 4 5 6 7 8 9 10	<0.20 <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 <0.20	<0.20	n.a.	<0.20	n.a.	6.3
12	1 2 3 4 5 6 7 8 9 10	<0.20 <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 <0.20	<0.20	n.a.			6.4

¹Mean of the concentrations was below the lowest calibration standard, taking the dilution factor of 2 into account.

Conclusions:

The column elution method was applied for the determination of the water solubility of Lowinox® AH25.
The water solubility of the test item at 20°C was < 0.2 μg/L. The pH of the aqueous samples was 6.3 – 6.4.

Executive summary:

The purpose of the study was to determine the following physico-chemical properties for Lowinox® AH25:

-Water solubility

 

The study was performed in accordance with the following guidelines:
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.

 

Two methods are available for the determination of the water solubility of a solid test item: Flask method and Column elution method. As determined in project 494311 the water solubility of the test item was < 0.08 mg/L. Accordingly the column elution method was carried out.

 

The column elution method was applied for the determination of the water solubility of Lowinox® AH25.

The water solubility of the test item at 20°C was < 0.2 μg/L. The pH of the aqueous samples was 6.3 – 6.4.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

22 June 2010-13 September 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study has been performed according to OECD and EC guidelines and according to GLP principles.

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:

yes (incl. QA statement)

Type of method:

column elution method

Key result

Water solubility:

< 0.08 mg/L

Temp.:

20 °C

pH:

7.5

Remarks on result:

other: The limit of detection (LOD) was determined to be 0.08 mg/l taking a dilution factor of two into account.

Preliminary test

The content of test substance dissolved in the water sample was 2.14 x10^-3 g/l.

Main study:

The water solubility of the test substance was given as the mean value of the measurements at both flow rates. No test substance was detected in the water samples. The limit of detection (LOD) was determined to be 0.08 mg/l taking a dilution factor of two into account.

 

No test substance was detected in the samples from the blank column.

No undissolved particles were detected in the eluates using the Tyndall effect.

Conclusions:

Interpretation of results (migrated information): insoluble (< 0.1 mg/L)
The column elution method was chosen for the determination of the water solubility of Lowinox® AH25. The water solubility of the test substance at 20°C was < 0.08 x 10-3 g/l. The pH of the aqueous samples was 7.5.

Executive summary:

The aim of the study was to determine the following physico-chemical properties for Lowinox® AH25: Water solubility in accordance with the following guidelines:

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

European Community (EC), EC no. 440/2008, Part A: Methods for the Determination of Physico-Chemical Properties, Guideline A.6: "Water Solubility", Official Journal of the European Union no. L 142, May 31, 2008.

 

A preliminary test was carried out as a range-finding test prior to performance of the column elution method or flask method.

 

Preliminary test

Test substance was stirred with double distilled water at a nominal concentration of 0.108 g/l at 20.1 ± 0.5 °C for 22 hours (1 day). After stirring, the water phase was centrifuged, treated and analysed. The centrifugation method was checked and was found to be sufficient to remove all undissolved test substance.

In the preliminary test the water solubility of the test substance was < 10-2 g/l. Therefore, the column elution method was chosen for the main study.

 

Main study

A solution with an absolute test substance quantity of 65.8 mg was prepared in acetone. The solution was mixed with 5 g LiChroprep Si 100 25-40 μm column material (Merck, Darmstadt, Germany). Acetone was completely evaporated at 40°C using a rotary evaporator. The loaded carrier material was stored at room temperature, prior to use. A 150 mm x 4.6 mm i.d. column was filled with the carrier material and 0.5 μm frits were used to enclose the column. Double distilled water was pumped through the column until it was completely filled. The system was allowed to equilibrate for two hours.

After the equilibration period, the column was eluted overnight with double distilled water at a flow rate of 12 ml/hour. The following day the flow was increased to 24 ml/hour. Ten consecutive samples of 2 ml were taken. The flow was halved to 12 ml/hour and ten consecutive samples of 2 ml were taken. The samples were diluted in a 1:1 (v:v) ratio with methanol and analysed.

After sampling, the remaining parts of the water samples were combined for pH measurement.

The pH was measured from the water fractions that were collected for the determination of the flow rates.

The eluates were checked for the presence of undissolved particles by examination for the Tyndall effect (light scattering). This was performed by recording an UV-Vis absorption spectrum between 200 nm and 900 nm.

The experiment was also performed using a column filled with blank carrier material. The procedure was identical to the procedure used for the column loaded with test substance. At each flow rate, two consecutive samples were taken for analyses.

The test was performed in a climate room where the temperature was 20.4 °C ± 0.6 °C.

 

Results

Preliminary test

The content of test substance dissolved in the water sample was 2.14 x 10-3 g/l.

 

Main study

The coefficient of variation (CV) (n = 10) was < 30% at both flow rates. The maximum difference (MD) on the water solubility was also < 30%. Therefore, the water solubility of the test substance was given as the mean value of the measurements at both flow rates. No undissolved particles were detected in the eluates using the Tyndall effect. No test substance was detected in the samples from the blank column. After the performance of the study it was confirmed that test substance was still present on the test substance column.

 

Conclusion

The column elution method was chosen for the determination of the water solubility of Lowinox® AH25. The water solubility of the test substance at 20 °C was < 0.08 x 10-3 g/l. The pH of the aqueous samples was 7.5.

Description of key information

The column elution method was applied The water solubility of the test item at 20°C was < 0.2 μg/L.

Key value for chemical safety assessment

Water solubility:

0.2 µg/L

at the temperature of:

20 °C

Additional information

Key Study

Two methods are available for the determination of the water solubility of a solid test item: Flask method and Column elution method. As determined in project 494311 the water solubility of the test item was < 0.08 mg/L. Accordingly the column elution method was carried out.

The column elution method was applied for the determination of the water solubility of Lowinox® AH25.

The water solubility of the test item at 20°C was < 0.2 μg/L. The pH of the aqueous samples was 6.3 – 6.4.

Supporting Study

A preliminary test was carried out as a range-finding test prior to performance of the column elution method or flask method.

In the preliminary test the water solubility of the test substance was < 10-2 g/l. Therefore, the column elution method was chosen for the main study.

 

Results

Preliminary test: The content of test substance dissolved in the water sample was 2.14 x 10-3 g/l.

 

Main study: The coefficient of variation (CV) (n = 10) was < 30% at both flow rates. The maximum difference (MD) on the water solubility was also < 30%. Therefore, the water solubility of the test substance was given as the mean value of the measurements at both flow rates. No undissolved particles were detected in the eluates using the Tyndall effect. No test substance was detected in the samples from the blank column. After the performance of the study it was confirmed that test substance was still present on the test substance column.

The column elution method was chosen for the determination of the water solubility of Lowinox® AH25. The water solubility of the test substance at 20 °C was < 0.08 x 10-3 g/l. The pH of the aqueous samples was 7.5.