2-Thiophenecarboxylic acid, 5-chloro-

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 Feb - 28 Feb 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Analytical monitoring:

yes

Remarks:

HPLC-UV

Details on sampling:

- Sampling method: Before, during and after the test period samples were taken and HPLC analysis were performed.

Buffers:

pH:4
buffer: citric acid / sodium hydroxide / sodium chloride, Riedel de Haen Art. No. 33643, ready to use solution

pH:7
buffer: potassium dihydrogen phosphate / Di-sodium hydrogen phosphate, Riedel de Haen Art. No. 33646, ready to use solution

pH: 9
buffer: borax / hydrochloric acid, Riedel de Haen Art. No. 33648, ready to use solution

Duration:

5 d

pH:

9

Temp.:

50 °C

Remarks:

The initial nominal test concentration was 18 mg/L

Duration:

5 d

pH:

7

Temp.:

50 °C

Remarks:

The initial nominal test concentration was 18 mg/L

Duration:

5 d

pH:

4

Temp.:

50 °C

Remarks:

The initial nominal test concentration was 18 mg/L

Number of replicates:

Three replicates

Positive controls:

no

Negative controls:

no

Preliminary study:

A preliminary study was performed and the results indicates that the test substance is hydrolytically stable at pH 4, pH 7, and pH 9 and no further study was performed.

Transformation products:

not measured

% Recovery:

99.3

pH:

9

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

% Recovery:

99.8

pH:

7

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

% Recovery:

99.4

pH:

4

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

9

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

7

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

4

Temp.:

50 °C

Remarks on result:

hydrolytically stable based on preliminary test

Validity criteria for the hydrolysis study:

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
The analytical method used will depend on the nature of the substance and must be sufficiently precise and sensitive to detect a reduction of 10 % of the initial concentration.	Analysis via HPLC-UV is senstive enough to detect a reduction of 10% of the initial concentration.	Yes
A sufficient number of samples (not less than four) should be chosen to cover the range 20 to 70 % of hydrolysis to test for pseudo-first order behaviour at the specified pH values.	pH 4 (50°C): 3 measurements pH 7 (50°C): 3 measurements pH 9 (50°C): 3 measurements The test substance is not degradable at pH 4, 7 and 9, therefore 3 measurements were sufficent to cover hydrolysis behavior.	Yes
The method must be specific to allow determination of the test substance at the test solution concentrations and may well consist of some combination of suitable analytical techniques.	The test substance was determined by HPLC-UV detection at 250 nm. Chromatograms of the test and calibration solutions demonstrate the specificity of the method.	Yes

 

Validity criteria fulfilled:

yes

Remarks:

See 'Any other information on results incl. tables'

Conclusions:

The test substance is not degradable at pH 4, pH 7 and pH 9.

Executive summary:

The study was performed to determine the hydrolysis of the test stubstance as a functon of pH according to EG guideline 92/69/EEC C.7. Solutions with a concentration of 0.11 mmol/L (18 mg/L) of the test substance in buffer soltuions with 1% solubilizer (acetonitrile) were tempered at 50°C for about 5 days. Results of preliminiary tests showed that within 5 days the degradation was less than 10% for the test substance at pH 4, pH 7 and pH 9. Based on the result the substance is considered hydrolytically stable at pH 4, pH 7, and pH 9.

Description of key information

A study was performed to determine the hydrolysis of the test stubstance as a functon of pH according to EG guideline 92/69/EEC C.7. Solutions with a concentration of 0.11 mmol/L (18 mg/L) of the test substance in buffer soltuions with 1% solubilizer (acetonitrile) were tempered at 50°C for about 5 days. Results of preliminiary tests showed that within 5 days the degradation was less than 10% for the test substance at pH 4, pH 7 and pH 9. Based on the result the substance is considered hydrolytically stable at pH 4, pH 7, and pH 9.