2-Propenamide, N-[4-[[(4,6-dimethyl-2-pyrimidinyl)amino]sulfonyl]phenyl]-2-methyl-

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

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)

Version / remarks:

March 04, 2016

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.2120 (Hydrolysis of Parent and Degradates as a Function of pH at 25°C)

Version / remarks:

October 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

March 04, 2016

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

The concentration of the test item in the test samples was determined immediately after preparation (t=0) and after 5 days. The samples taken at t=5 days were cooled to room temperature using running tap water.
The samples were diluted in a 3:1 (v:v) ratio with acetonitrile and analyzed.
Blank buffer solutions containing a similar content of blank spiking solution were treated similarly as the test samples and analyzed at t=0.

Buffers:

Acetate buffer pH 4, 0.1 M
Solution of 16.7% 0.1 M sodium acetate in water and 83.3% 0.1 M acetic acid in water. Buffer contained 0.0009% (w/v) sodium azide.
Phosphate buffer pH 7, 0.1 M
Solution of 0.1 M potassium di-hydrogen-phosphate in water adjusted to pH 7 using 1N sodium hydroxide. Buffer contained 0.0009% (w/v) sodium azide.
Borate buffer pH 9, 0.1 M
Solution of 0.1 M boric acid in water and 0.1 M potassium chloride in water adjusted to pH 9 using 1N sodium hydroxide. Buffer contained 0.0009% (w/v) sodium azide.

Details on test conditions:

The buffer solutions were filter-sterilised through a 0.2 µm FP 30/0.2 CA-S filter (Whatman, Dassel, Germany) and transferred into a sterile vessel. To exclude oxygen, nitrogen gas was purged through the solution for 5 minutes. The test item was spiked to the solutions at a target concentration of 2 mg/L using a spiking solution in acetonitrile. For each sampling time, duplicate sterile vessels under vacuum were filled with 6 mL test solution and placed in the dark in a temperature controlled environment at 50.1°C +- 0.1°C.
The spiking volume was < 1% of the sample volume. Nominal concentrations were not corrected for the spiking volume.

Positive controls:

no

Negative controls:

yes

Preliminary study:

At pH 4, pH 7 and pH 9, a degree of hydrolysis of < 10% was observed after 5 days. It demonstrated that the half-life time of the test item at 25°C is > 1 year. According to the guideline, no further tests were required.

Test performance:

No test item was detected in the blank buffer solutions.
The mean recoveries of the of the test item containing buffer solutions at t=0 fell within the criterion range of 90-110%. It demonstrated that the analytical method was adequate to support the hydrolysis study on the test item.

Transformation products:

not measured

% Recovery:

104

pH:

4

Temp.:

20 °C

% Recovery:

104

pH:

7

Temp.:

20 °C

% Recovery:

105

pH:

9

Temp.:

20 °C

Remarks on result:

hydrolytically stable based on preliminary test

Other kinetic parameters:

Degree of hydrolysis (%)
pH 4: 7.2
pH 7: 4.3
pH 9: 3.3

Validity criteria fulfilled:

yes

Conclusions:

The preliminary test (Tier 1) was performed for the determination of the rate of hydrolysis of V123109 at pH values normally found in the environment (pH 4-9).
At each pH value a degree of hydrolysis of < 10% was observed after 5 days. According to the guideline, performance of the main study (Tier 2) was not required.
The half-life times of the test item were as follows:
pH 4: > 1 year
pH 7: > 1 year
pH 9: > 1 year

Description of key information

The half-life times of the test item were as follows:
pH 4: > 1 year
pH 7: > 1 year
pH 9: > 1 year

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

20 °C