2-bromo-5-hydroxy-4-methoxybenzaldehyde

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998-01-06 to 1998-03-10

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The purity of the test substance was 91.3 % (according to OECD 111 the purity of the test substance should be at least 95%).

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

yes

Remarks:

- Lighting conditions during the incubation period not reported. - Purity of test substance: 91.3 %

Qualifier:

according to guideline

Guideline:

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

Principles of method if other than guideline:

not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate issued by the Swiss GLP monitoring authorities.

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 00265786
- Expiration date of the lot/batch: 1998-07-01 (retest date)
- Purity test date: no data

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature at about 20°C

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

- Sampling intervals for the parent/transformation products: before the start of incubation, at 2.4 and 120 hours
- Sampling method: no data
- Sampling methods for the volatile compounds, if any: no data
- Sampling intervals/times for pH measurements: not performed
- Sampling intervals/times for sterility check: not performed
- Sample storage conditions before analysis: no data
- Other observation, if any (e.g.: precipitation, color change etc.): no data

Buffers:

- pH: 4, 7, 9
- Type and final molarity of buffer: biphthalate (pH 4.0); phosphate (pH 7.0); borate/potassium chloride/NaOH (pH 9.0), the final molarity not provided
- Composition of buffer: The buffer solutions contained 2% dimethylformamide (DMF) as a solubilizing agent. The buffer solutions were sterilized for 25 minutes in an autoclave prior to first use. Nitrogen was passed through the buffer solutions for 2 minutes except when freshly sterilized.

Estimation method (if used):

not applicable

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: The hydrolysis was carried out in glass Erlenmeyer flasks which were stoppered or sealed with an inert material (e.g., PTFE).
- Sterilisation method: All glassware was inert in the applied pH range applied and was rinsed with sterile buffer. The buffer solutions were sterilized for 25 minutes in an autoclave prior to first use.
- Lighting: no data
- Measures taken to avoid photolytic effects: no data
- Measures to exclude oxygen: Nitrogen was passed through the buffer solutions for 2 minutes except when freshly sterilized.
- Details on test procedure for unstable compounds: not applicable
- Details of traps for volatile, if any: not applicable
- If no traps were used, is the test system closed/open: The hydrolysis was carried out in flasks which were stoppered or sealed with an inert material (e.g. PTFE).
- Is there any indication of the test material adsorbing to the walls of the test apparatus?: no data

TEST MEDIUM
- Volume used/treatment: 50 mL
- Kind and purity of water: Milli-Q
- Preparation of test medium: Appropriate amounts of the test substance were dissolved in 100 mL buffer solution (pH 4.0 - ph 7.0 and pH9) containing 2 %
DMF as solubilizer. This mixture was ultrasonified for 1 minute and was passed through a 0.45 µm polyamide filter. 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.
- Renewal of test solution: no
- Identity and concentration of co-solvent: DMF (2%)

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Dissolved oxygen: no data

Duration:

120 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

>= 89.1 - <= 89.8 mg/L

Duration:

120 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

>= 80 - <= 80.7 mg/L

Duration:

120 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

>= 95 - <= 95.1 mg/L

Number of replicates:

2

Positive controls:

no

Negative controls:

no

Statistical methods:

no data

Preliminary study:

The results at pH 4.0, 7.0 and pH 9.0 showed no significant degradation of T002019 at 50 °C. According to the guideline, no further tests were required.

Test performance:

There were no circumstances that may have affected the quality or integrity of the study.

Transformation products:

not measured

Details on hydrolysis and appearance of transformation product(s):

- Formation and decline of each transformation product during test: no data
- Pathways for transformation: no data
- Other: no data

% Recovery:

> 90

pH:

4

Temp.:

50 °C

Duration:

120 h

% Recovery:

> 90

pH:

7

Temp.:

50 °C

Duration:

120 h

% Recovery:

> 90

pH:

9

Temp.:

50 °C

Duration:

120 h

Key result

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Other kinetic parameters:

no data

Validity criteria fulfilled:

not specified

Conclusions:

The hydrolysis determination of T002019 at pH 4.0, 7.0 and 9.0 (OECD 111) showed no significant degradation of the test substance at 50°C. The degradation of the test substance was less than 10 % after 5 days. It can be concluded, that the estimated half-life time is higher than one year under representative environmental conditions (25°C). Therefore, the test substance was considered to be hydrolytically stable, and no further testing was necessary. The results of the test can be considered reliable with restriction: the fulfilling of the validity criteria were not specified. Moreover a purity of 91.3 % was reported for the test substance (according to OECD 111 the purity of the test substance should be at least 95%).

Description of key information

One study (Tognucci, 1998) was performed according to OECD guideline 111 and regarded as a key study (Klimisch score of 2). A half-life time of > 1 year at 25 °C and pH 7, was determined for T002019.