.beta.-Alanine, N-[2-chloro-4-[2-(4-nitrophenyl)diazenyl]phenyl]-, 2-[2-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)ethoxy]-2-oxoethyl ester

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From February 15 to May 14, 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Version / remarks:

1981

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1992

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Yellow 981

IUPAC Name:

Yellow 981

Test material form:

solid: particulate/powder

Study design

Analytical monitoring:

yes

Buffers:

pH 4, 7, 9

Duration of test

Duration of test 1

Duration:

2.4 h

pH:

4

Temp.:

50 °C

Duration of test 2

Duration:

2.4 h

pH:

7

Temp.:

50 °C

Duration of test 3

Duration:

2.4 h

pH:

9

Temp.:

50 °C

Number of replicates:

2

Positive controls:

no

Negative controls:

no

Results and discussion

Preliminary study:

The preliminary study demonstrated a half-life of less than one day at pH 4 and 9 (degradation of over 50 % within 2.4 hours), therefore, the substance is considered hydrolytically unstable and no main test was required.
The solubility of test item in buffer solution pH 7.0 is too low to follow the degradation.

Test performance:

Performance of the test
A preliminary test was performed at 50.2 °C at each of pH 4.0, pH 7.0 and pH 9.0. Aliquots of each test solution were analysed in time intervals using HPLC-UV/vis. Analysis was performed before incubation, after 2.4 hours and after 120 hours.

Preparation of the test solutions
pH 4.0
12.5 mg of test item were dissolved in 100 ml buffer solution (pH a.0) containing 2 % dimethylformamide as solubilizer. This mixture was ultrasonified for 3 minutes and submitted to a 0.2 µm filtration. To obtain a test solution of not more than half the water solubility, the solution was diluted 1:1 with the respective buffer. Two aliquots of this test solution of approximately 50 ml each were transferred into 50 ml Erlenmeyer flasks in order to perform a duplicate test.

pH 7.0
11.8 mg of test item were dissolved in 100 ml buffer solution (pH 7.0) containing 2 % dimethylformamide as solubilizer. This mixture was ultrasonified for 3 minutes and submitted to a 0.2 pm filtration. To obtain a test solution of not more than half the water solubility, the solution was diluted 1:1 with the respective buffer. Two aliquots of this test solution of approximately 50 ml each were transferred into 50 ml Erlenmeyer flasks in order to perform a duplicate test.

pH 9.0
10.3 mg of test item were dissolved in 100 ml buffer solution (pH 9.0) containing 2 % dimethylformamide as solubilizer. This mixture was ultrasonified for 3 minutes and submitted to a 0.2 pm filtration. To obtain a test solution of not more than half the water solubility, the solution was diluted 1:1 with the respective buffer. Two aliquots of this test solution of approximately 50 ml each were transferred into 50 ml Erlenmeyer flasks in order to perform a duplicate test.

Transformation products:

not specified

Total recovery of test substance (in %)

Total recovery of test substance (in %) 1

% Recovery:

< 50

pH:

4

Temp.:

50 °C

Duration:

2.4 h

Total recovery of test substance (in %) 2

pH:

7

Temp.:

50 °C

Duration:

2.4 h

Remarks on result:

other: poor solubility

Total recovery of test substance (in %) 3

% Recovery:

< 50

pH:

9

Temp.:

50 °C

Duration:

2.4 h

Dissipation DT50 of parent compound

Dissipation DT50 of parent compound 1

pH:

4

Temp.:

25 °C

DT50:

< 1 d

Type:

not specified

Dissipation DT50 of parent compound 2

pH:

9

Temp.:

25 °C

DT50:

< 1 d

Type:

not specified

Dissipation DT50 of parent compound 3

pH:

7

Remarks on result:

not determinable because of methodological limitations

Remarks:

solubility too low

Details on results:

The results of pH 4.0 and pH 9.0 showed a significant degradation of test item at 50 °C.
The degradation of test item was higher than 50 % after 2.4 hours. Accordingly, it can be concluded, that the estimated half-life time is shorter than one day under representative environmental conditions (25 °C). Therefore, test item was considered to be hydrolytically unstable, and no further testing was necessary at these pH values.
The solubility of test item in buffer solution pH 7.0 is too low to follow the degradation. A main test was not possible.

Applicant's summary and conclusion

Conclusions:

Half-life of the substance at 25 °C and pH 4 and 9 is less than one day, thus, it is hydrolytically unstable.