Vinylphosphonic acid

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2018-05-14 to 2018-06-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Analytical monitoring:

yes

Remarks:

HPLC-UV

Details on sampling:

At the start of the test five samples were taken from the test solutions and two samples were taken from the control buffers with two parallel of each. At the end of the test the treated samples were diluted with ultrapure water before the analysis. The control samples were measured without dilution.

Buffers:

- pH: 4
- Composition of buffer: 6.45 g citric acid monohydrate, 13.8 g di-sodium hydrogen phosphate dodecahydrate in 500 mL ultrapure water

- pH: 7
- Composition of buffer: 74 mL 0.2 M sodium hydroxide, 125 mL 0.2 M potassium dihydrogen phosphate in 500 mL ultrapure water

- pH: 9
- Composition of buffer: 53.5 mL 0.2 M sodium hydroxide, 125 mL 0.2 M boric acid - potassium chloride solution in 500 mL ultrapure water

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: screw-cap glass tubes with PTFE septa
- Sterilisation: yes
- Lighting: no
- Measures taken to avoid photolytic effects: The test was performed under darkness to avoir photolytic effects.
- Measures to exclude oxygen: Nitrogen was bubbled into the water for five minutes before the preparation of the solutions in order to exclude oxygen.
- If no traps were used, is the test system closed/open: closed with PTFE septa

TEST MEDIUM
- Volume used/treatment; 500 mL
- Kind and purity of water: ultrapure

OTHER TEST CONDITIONS
- Adjustment of pH: no

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

>= 1 032.5 - <= 1 047.7 mg/L

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

>= 1 050.9 - <= 1 073.3 mg/L

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

>= 1 022 - <= 1 041.4 mg/L

Number of replicates:

5

Positive controls:

no

Negative controls:

yes

Preliminary study:

Hydrolysis at pH 4, 7 and 9 was not observed - 0 to 2 % of the test item hydrolysed after 5 days. Therefore, the test item is considered to be hydrolytically stable and no main test was performed.

Transformation products:

not measured

% Recovery:

ca. 102

pH:

4

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

% Recovery:

ca. 101

pH:

7

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

% Recovery:

ca. 102

pH:

9

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

4

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

7

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

9

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

Validity criteria fulfilled:

yes

Conclusions:

The test item was determined to be hydrolytically stable at pH 4, 7 and 9 in the preliminary test.

Executive summary:

The hydrolysis of the test item was assessed in accordance with the OECD guideline 111 and the EU method C.7 in a preliminary test. The hydrolysis of the test item in different aqueous buffer solutions (pH = 4, 7 and 9) at 50 °C was investigated using HPLC-UV. The content of test item in the different pH buffer samples was determined at the beginning and the end of the test period. Five samples of the test item solutions were analysed at the start of the study. Two samples were taken from the control vessels at the start and at the end of the storage and these were measured without dilution. Less than 10 % of hydrolysis was observed after 5 days at each pH value. Based on the results obtained, test substance can be considered to be hydrolytically stable at pH 4, pH 7 and pH 9 under the conditions investigated.

Description of key information

The test item was determined to be hydrolytically stable at pH 4, 7 and 9 in the preliminary test.

Additional information

The hydrolysis of the test item was assessed in accordance with the OECD guideline 111 and the EU method C.7 in a preliminary test. The hydrolysis of the test item in different aqueous buffer solutions (pH = 4, 7 and 9) at 50 °C was investigated using HPLC-UV. The content of test item in the different pH buffer samples was determined at the beginning and the end of the test period. Five samples of the test item solutions were analysed at the start of the study. Two samples were taken from the control vessels at the start and at the end of the storage and these were measured without dilution. Less than 10 % of hydrolysis was observed after 5 days at each pH value. Based on the results obtained, test substance can be considered to be hydrolytically stable at pH 4, pH 7 and pH 9 under the conditions investigated.