2-ethyl-N-(3-methoxyphenyl)-N-methylbutanamide

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 10 May 2018 and 11 June 2018.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Reliability 1 is assigned because the study conducted according to OECD TG (2006) No 111 in compliance with GLP, without deviations that influence the quality of the results.

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Identification: FRET 15-0735
Appearance/physical state: clear, colorless liquid
Storage conditions: room temperature, in the dark

Analytical monitoring:

yes

Remarks:

High performance liquid chromatography (HPLC)

Details on sampling:

The sample solutions were taken from the waterbath at various times and the pH of each solution recorded.

Samples
Duplicate aliquots (A and B) of each initial sample solution were diluted by a factor of 4, using methanol, for analysis. For the following samples, duplicate, independently incubated vessels were removed from the waterbath for each pH under evaluation, at each time point. An aliquot of each incubated sample was then diluted by a factor of 4, using methanol, prior to analysis.

Standards
Duplicate standard solutions of test item were prepared in methanol: relevant buffer solution (75:25 v/v) at a nominal concentration of 100 mg/L.

Matrix blanks
Methanol: relevant buffer solution (75:25 v/v).

Buffers:

The test system consisted of sterile buffer solutions at pH’s 4, 7 and 9.
Buffer solution(pH) Components Concentration(mol dm-3)
4 Citric acid 0.06
Sodium chloride 0.04
Sodium hydroxide 0.07
7 Disodium hydrogen orthophosphate (anhydrous) 0.03
Potassium dihydrogen orthophosphate 0.02
Sodium chloride 0.02
9 Disodium tetraborate 0.01
Sodium chloride 0.02

These solutions were subjected to ultrasonication and degassing with nitrogen to minimize dissolved oxygen content.

Details on test conditions:

Preparation of the Test Solutions
Sample solutions were prepared in stoppered glass flasks at a nominal concentration of 0.40 g/L in the three buffer solutions. A 1% co-solvent of acetonitrile was used to aid solubility.
The test solutions were split into individual vessels for each data point.
The solutions were shielded from light whilst maintained at the test temperature.

Preliminary Test
Sample solutions at pH 4, 7 and 9 were maintained at 50.0 ± 0.5 °C for a period of 120 hours.

Duration:

120 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

0.4 g/L

Duration:

120 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

0.4 g/L

Duration:

120 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

0.39 g/L

Number of replicates:

Duplicate

Positive controls:

no

Negative controls:

yes

Remarks:

Matrix blank

Preliminary study:

No significant responses were observed in any matrix blank solution at the retention time of the test item during analysis.
pH 4 at 50.0 ± 0.5 ºC: Less than 10% hydrolysis after 5 days at 50 °C, equivalent to a half-life greater than 1 year at 25 °C.
pH 7 at 50.0 ± 0.5 ºC: Less than 10% hydrolysis after 5 days at 50 °C, equivalent to a half-life greater than 1 year at 25 °C.
pH 9 at 50.0 ± 0.5 ºC: Less than 10% hydrolysis after 5 days at 50 °C, equivalent to a half-life greater than 1 year at 25 °C.

Test performance:

The linearity of the detector response with respect to concentration was assessed over the nominal concentration range of 10 to 150 mg/L for each of the three analytical matrices used during the study. The results were satisfactory, with first order correlation coefficients (r) of 0.9998 being obtained for all three plots.

Transformation products:

not measured

Remarks on result:

hydrolytically stable based on preliminary test

Remarks on result:

hydrolytically stable based on preliminary test

Preliminary Test

The mean peak areas relating to the standard and sample solutions are shown in the following table:

Solution	Mean Peak Area
Standard 102 mg/L	9.1348 x 10^6
Standard 102 mg/L	9.1677 x 10^6
Initial Sample A, pH 4	9.0222 x 10^6
Initial Sample B, pH 4	9.0746 x 10^6
Standard 102 mg/L	9.1752 x 10^6
Standard 102 mg/L	9.2929 x 10^6
Initial Sample A, pH 7	9.1242 x 10^6
Initial Sample B, pH 7	9.1206 x 10^6
Standard 102 mg/L	9.1911 x 10^6
Standard 102 mg/L	9.2513 x 10^6
Initial Sample A, pH 9	9.0256 x 10^6
Initial Sample B, pH 9	9.0171 x 10^6
Standard 101 mg/L	8.9849 x 10^6
Standard 100 mg/L	8.9757 x 10^6
24 Hour Sample A, pH 4	9.0225 x 10^6
24 Hour Sample B, pH 4	9.0208 x 10^6
Standard 101 mg/L	9.0898 x 10^6
Standard 100 mg/L	9.0924 x 10^6
24 Hour Sample A, pH 7	9.1995 x 10^6
24 Hour Sample B, pH 7	9.1594 x 10^6
Standard 101 mg/L	9.0191 x 10^6
Standard 100 mg/L	9.0122 x 10^6
24 Hour Sample A, pH 9	9.0843 x 10^6
24 Hour Sample B, pH 9	9.0317 x 10^6
Standard 101 mg/L	9.0175 x 10^6
Standard 100 mg/L	9.0592 x 10^6
120 Hour Sample A, pH 4	8.9478 x 10^6
120 Hour Sample B, pH 4	9.1025 x 10^6

 

Solution	Mean Peak Area
Standard 101 mg/L	9.1470 x 10^6
Standard 100 mg/L	9.1502 x 10^6
120 Hour Sample A, pH 7	9.1354 x 10^6
120 Hour Sample B, pH 7	9.1006 x 10^6
Standard 101 mg/L	9.0798 x 10^6
Standard 100 mg/L	9.0518 x 10^6
120 Hour Sample A, pH 9	9.0420 x 10^6
120 Hour Sample B, pH 9	9.0586 x 10^6

pH 4 at 50.0 ± 0.5 ºC

Time (Hours)	Concentration (g/L)		% of mean initial concentration
	A	B	A	B
0	0.402	0.404	-	-
24	0.404	0.404	100	100
120	0.399	0.406	99.0	101

pH 7 at 50.0 ± 0.5 ºC

Time (Hours)	Concentration (g/L)		% of mean initial concentration
	A	B	A	B
0	0.403	0.402	-	-
24	0.407	0.405	101	101
120	0.402	0.401	99.9	99.6

pH 9 at 50.0 ± 0.5 ºC

Time (Hours)	Concentration (g/L)		% of mean initial concentration
	A	B	A	B
0	0.399	0.398	-	-
24	0.405	0.403	102	101
120	0.402	0.402	101	101

Validity criteria fulfilled:

yes

Conclusions:

The hydrolysis of the test item, FRET 15-0735, was assessed according to OECD Test Guideline 111.
The estimated half-life of the test item at 25 °C is shown in the following table:
pH Estimated Half-life at 25 °C
4 >1 year
7 >1 year
9 >1 year

Executive summary:

Assessment of the hydrolytic stability of FRET 15-0735was carried out using a procedure designed to be compatible with Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004. The results are as follows:

pH	Estimated Half-life at 25 °C
4	>1 year
7	>1 year
9	>1 year

Description of key information

Assessment of the hydrolytic stability of FRET 15-0735was carried out using a procedure designed to be compatible with Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004. The results are as follows:

pH	Estimated Half-life at 25 °C
4	>1 year
7	>1 year
9	>1 year

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

25 °C