3-methoxy-N,N-dimethylpropionamide

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 19 September 2011 to 24 September 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

other: Reference to the HPLC analytical method used for quantification of the hydrolysis samples.

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Version / remarks:

2004

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2008

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

PREPARATION OF THE SAMPLES
- 250 mL sterile solutions were prepared.
- To exclude oxygen, nitrogen gas was purged through the solutions for 5 minutes.
- The solutions were transferred into 20 mL screw cap tubes
- Five replicate samples and one control.


SAMPLING DETAILS
- Samples for analysis were taken at the start (t=0) and after 5 days of incubation.

Buffers:

- Buffer pH 4: 2 ml 0.2 M Sodium hydroxide and 250 ml 0.2 M Potassium hydrogen phthalate diluted to 1000 ml with water
- Buffer pH 7: 147.8 ml 0.2 M Sodium hydroxide and 250 ml 0.2 M Potassium dihydrogen phosphate diluted to 1000 ml with water
- Buffer pH 9: 107 ml 0.2 M Sodium hydroxide and 250 ml 0.2 M Boric acid and Potassium chloride diluted to 1000 ml with water.

- Type of water: tap water purified by a Millipore purification system, sterile

Details on test conditions:

The tubes were thermostated at 50°C ± 1 °C in the dark.

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

1.29 g/L

Remarks:

mean

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

1.3 g/L

Remarks:

mean

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

1.3 g/L

Remarks:

mean

Number of replicates:

5

Positive controls:

no

Negative controls:

no

Preliminary study:

Concentration analysed (mean) after 5 days:
pH4: 1.28 g/L
pH 7: 1.26 g/L
pH 9: 1.27 g/L

At pH 4, 7 and pH 9, hydrolysis < 10% was observed after 5 day. According to the guideline, no further tests were required.

Transformation products:

no

Key result

pH:

4

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

7

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

9

Remarks on result:

hydrolytically stable based on preliminary test

Conclusions:

The substance is hydrolytically stable at pH 4, 7 and 9 (half-life time at 25°C of > 1 year).

Executive summary:

The rate of hydrolysis of the substance at pH values normally found in the environment (pH 4-9) was determined in a GLP-compliant study according to EC C.7 and OECD 111. In the preliminary Tier 1 study, a degree of < 10% of hydrolysis was observed at pH 4, 7 and 9 after 5 days at 50°C. This corresponds with a half-life time at 25°C of > 1 year and the substance can be considered hydrolytically stable at pH 4, 7 and 9.

Description of key information

The substance is hydrolytically stable at pH 4, 7 and 9 (half-life time at 25°C of > 1 year).

Key value for chemical safety assessment

at the temperature of:

25 °C

Additional information

A preliminary Tier 1 study was performed at 50°C (EC C.7, OECD 111, OPPTS 830.2120). The buffers were prepared in tap water purified by a Millipore purification system.