Tar bases, coal, lutidine fraction

Hydrolysis

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Experimental start: 27 March 2017, Experimental completion: 03 April 2017, Final Report: 12 December 2017

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

Triplicate samples were taken at the begin of the study (immediately after preparation of the test solutions) and after 5 days.

Buffers:

- pH: 4
- Type and final molarity of buffer: 0.01
- Composition of buffer: citrate/hydrochloric acid buffer prepared in sterile ultra pure water

- pH: 7
- Type and final molarity of buffer: 0.01
- Composition of buffer: hydrogenphosphate/dihydrogenposphate buffer prepared in sterile ultra pure water


- pH: 9
- Type and final molarity of buffer: 0.01
- Composition of buffer: Borid acid/potassium chloride/sodium hydroxide buffer prepared in sterile utra pure water

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: glass vials and screw caps
- Sterilisation method: test vessels and screw caps were removed from freshly opened packings, no further sterilisation applied
- Lighting: dark
- Measures taken to avoid photolytic effects: not applicable
- No traps for volatiles were used
- If no traps were used, is the test system closed/open
- There was no indication of the test material adsorbing to the walls of the test apparatus

TEST MEDIUM
- Volume used/treatment
- Kind and purity of water: sterile water was used to prepare buffers
- Preparation of test medium: for tier 1 experiments, a stock solution of the test substance was prepared by dissolving 19.6 mg test substance (purity 99.6%) in 20 mL of acetonitrile in a volumetric flask. A treatment solution of 10 µg pure substance per mL was prepared by dissolving 204.9 µL of the stock solution in 20 mL of acetonitrile in a volumetric flask. Triplicate vessels were prepared for each sampling time. 0.99 mL of the respective buffer solution was transferred into each test vessel and 10 µL of the solution of test substance in acetonitrile was added.
- Identity and concentration of co-solvent: acetonitrile (for details see above)

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

0.104 µg/L

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

0.109 µg/L

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

0.106 µg/L

Number of replicates:

3

Positive controls:

no

Negative controls:

no

Preliminary study:

Less than 10% hydrolysis of the test substance was observed at 50 °C over a period of 5 days at pH 4, 7 and 9.Therefore, the test substance is considered to be hydrolytically stable.

Transformation products:

no

pH:

4

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

pH:

7

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

pH:

9

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

Validity criteria fulfilled:

yes

Conclusions:

The test substance 2,4-lutidine, a major component of CA3490A, was hydrolytically stable.

Executive summary:

A study on the hydrolysis of the test substance 2,4-lutidine, a major component of CA3490A, was conducted under GLP in accordance with OECD TG 111 (version 2004). The experiment is considered relevant, adequate and conclusive.

Appropriate buffer solutions were prepared in sterile water to achieve pH 4, 7 and 9. A stock solution of the test substance in acetonitrile was prepared. An aliquot of 0.99 mL of the appropriate buffer solution was filled into 1.5 mL glass vials, and 0.1 mL of the solution of test substance in acetonitrile was added. The vials were then closed with screw caps. Three replicates per sampling point (at start of the experiment and after 5 days) were prepared for each pH value. All preliminary tests were conducted at 50 °C in the dark over a period of five days. The concentration of the test substance in the test solutions was analysed by HPLC with MS detection. At 50 °C over 5 days, parent compound concentration varied from 104.0% at day 0 to 96.9% of the nominal concentration at pH 4, from 109.3% to 102.2% at pH 7 and from 106.3 to 101.0% at pH 9. Less than 10% hydrolysis of 2,4-Lutidine was observed at 50 ± 0.5°C over 5 days at pH 4, 7 and 9. Therefore, 2,4-lutidine, a major component of CA3490A, is considered to be hydrolytically stable.

Reference 2

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Experimental start: 05 April 2017, Experimental completion: 22 May 2017, Report finalisation: 12 December 2017

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

Triplicate samples were taken at the begin of the study (immediately after preparation of the test solutions) and after 5 days.

Buffers:

- pH: 4
- Type and final molarity of buffer: 0.01
- Composition of buffer: citrate/hydrochloric acid buffer prepared in sterile ultra pure water

- pH: 7
- Type and final molarity of buffer: 0.01
- Composition of buffer: hydrogenphosphate/dihydrogenposphate buffer prepared in sterile ultra pure water


- pH: 9
- Type and final molarity of buffer: 0.01
- Composition of buffer: Borid acid/potassium chloride/sodium hydroxide buffer prepared in sterile utra pure water

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: glass vials and screw caps
- Sterilisation method: test vessels and screw caps were removed from freshly opened packings, no further sterilisation applied
- Lighting: dark
- Measures taken to avoid photolytic effects: not applicable
- No traps for volatiles were used
- If no traps were used, is the test system closed/open
- There was no indication of the test material adsorbing to the walls of the test apparatus

TEST MEDIUM
- Volume used/treatment
- Kind and purity of water: sterile water was used to prepare buffers
- Preparation of test medium: for tier 1 experiments, a stock solution of the test substance was prepared by dissolving 19.6 mg test substance (purity 99.6%) in 20 mL of acetonitrile in a volumetric flask. A treatment solution of 10 µg pure substance per mL was prepared by dissolving 204.9 µL of the stock solution in 20 mL of acetonitrile in a volumetric flask. Triplicate vessels were prepared for each sampling time. 0.99 mL of the respective buffer solution was transferred into each test vessel and 10 µL of the solution of test substance in acetonitrile was added.
- Identity and concentration of co-solvent: acetonitrile (for details see above)

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

0.094 µg/L

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

0.103 µg/L

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

0.102 µg/L

Number of replicates:

3

Positive controls:

no

Negative controls:

no

Preliminary study:

Less than 10% hydrolysis of the test substance was observed at 50 °C over a period of 5 days at pH 4, 7 and 9.Therefore, the test substance is considered to be hydrolytically stable.

Transformation products:

no

pH:

4

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

pH:

7

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

pH:

9

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

Validity criteria fulfilled:

yes

Conclusions:

The test substance 2,5-lutidine, a major component of CA3490A, was hydrolytically stable.

Executive summary:

A study on the hydrolysis of the test substance 2,5-lutidine, a major component of CA3490A, was conducted under GLP in accordance with OECD TG 111 (version 2004). The experiment is considered relevant, adequate and conclusive.

Appropriate buffer solutions were prepared in sterile water to achieve pH 4, 7 and 9. A stock solution of the test substance in acetonitrile was prepared. An aliquot of 0.99 mL of the appropriate buffer solution was filled into 1.5 mL glass vials, and 0.1 mL of the solution of test substance in acetonitrile was added. The vials were then closed with screw caps. Three replicates per sampling point (at start of the experiment and after 5 days) were prepared for each pH value. All preliminary tests were conducted at 50 °C in the dark over a period of five days. The concentration of the test substance in the test solutions was analysed by HPLC with MS detection. At 50°C over 5 days, parent compound concentration varied from 94.0% at day 0 to 102.7% of the nominal concentration at pH 4, from 102.9% to 103.7% at pH 7 and from 102.4% to 105.4% at pH 9. Less than 10% hydrolysis of 2,5-Lutidine was observed at 50 ± 0.5°C over 5 days at pH 4, 7 and 9. Therefore, 2,4-lutidine, a major component of CA3490A, is considered to be hydrolytically stable.

Description of key information

Hydrolysis studies were conducted with two main constituents of the substance, 2,4-lutidine and 2,5-lutidine. Less than 10% hydrolysis of the test substances was observed at a temperature of 50 °C and at pH values of 4, 7 and 9 over a period of five days. It is therefore concluded that the test substances are not hydrolysable under environmentally relevant conditions, demonstrating that the two main constituents of the UVCB substance, which are representative of other dimethylpyridines contained in the substance, are not hydrolysable. Furthermore, the UVCB substance contains a range of methylpyridines, such as 4- and 3-methylpyridine. No significant hydrolysis of these substances is anticipated, as their molecular structure lacks functional groups that hydrolyse under environmental conditions. However, these substances are readily biodegradable, and hydrolysis studies were not conducted. It is concluded that the UVCB substance is not undergoing hydrolysis under environmental conditions.