4-propylcyclohexanone

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1990-09-12 to 1990-09-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

yes

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

Samples were taken immediately after the start of the test and after 2.4 h and 5 days.

Buffers:

- pH 4.0: 50 mL potassium dihydrogen phosphate solution (0.1 mol/L) at 50 °C pH adjusted to 4.0 with HCL (0.1 mol/L), diluted with water to 100 mL.
- pH 7.0: 50 mL potassium dihydrogen phosphate solution (0.1 mol/L) at 50 °C pH adjusted to 7.0 with NaOH (0.1 mol/L), diluted with water to 100 mL.
- pH 9.0: 50 mL boric acid solution (0.1 mol/L in KCl (0.1 mol/L) at 50 °C pH adjusted to 9.0 with NaOH (0.1 mol/L), diluted with water to 100 mL.

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks: Iodine determination flask, brown glass, 100 mL
- Measures to exclude oxygen: flasks aerated with nitrogen gas
- Is the test system closed/open: closed system
- Is there any indication of the test material adsorbing to the walls of the test apparatus? No

TEST MEDIUM
- Volume used/treatment: 50 mL
- Renewal of test solution: no

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

400 mg/L

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

400 mg/L

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

400 mg/L

Number of replicates:

3

Positive controls:

yes

Remarks:

acetylsalicylic acid

Negative controls:

not specified

Statistical methods:

Mean values and standard deviation were calculated with a programmed pocket calculator (TI SR-51-11).

Transformation products:

not measured

% Recovery:

92.73

St. dev.:

6.66

pH:

4

Temp.:

50 °C

Duration:

5 d

% Recovery:

87.5

St. dev.:

3.02

pH:

4

Temp.:

50 °C

Duration:

2.4 h

% Recovery:

86.63

St. dev.:

4.9

pH:

7

Temp.:

50 °C

Duration:

5 d

% Recovery:

81.77

St. dev.:

5.04

pH:

7

Temp.:

50 °C

Duration:

2.4 h

% Recovery:

96.6

St. dev.:

3.8

pH:

9

Temp.:

50 °C

Duration:

5 d

% Recovery:

88.57

St. dev.:

4.47

pH:

9

Temp.:

50 °C

Duration:

2.4 h

Key result

pH:

4

Temp.:

50 °C

DT50:

> 1 yr

Type:

not specified

Key result

pH:

7

Temp.:

50 °C

DT50:

> 1 yr

Type:

not specified

Key result

pH:

9

Temp.:

50 °C

DT50:

> 1 yr

Type:

not specified

Details on results:

The test substance is an arylketone, theoretical no hydrolisation is possible. The test results after 2.4 h exposure in aqueous medium in a decrease in concentration of approx. 10-20%. Since the values are again higher after 5 days it can be assumed that this decline is not due to degradation, but an artifact of the method could be responsible. As the water solubility of the substance is not good, the determination of the concentration is only possible with a relatively large error. The results lead to a DT50 of the test substance in the environment of more than one year.

Results with reference substance:

The reference substance acetylsalicylic acid is totally hydrolysed after 5 days at pH 7 and 9. After 5 days at pH 4 0.1% of the start concentration was measured. After 2.4 h at pH 4 72.73 % of the start concentration were measured, at pH 7 50.93% and at pH 9 45.60%.

Validity criteria fulfilled:

yes

Conclusions:

The hydrolysis of the test substance was determined according to OECD 111. Under the given conditions the DT50 is more than one year.

Executive summary:

The hydrolysis of the test substance was determined according to OECD TG 111. The test substance (400 mg/L) and 50 mL of the buffer solution (pH 4, 7 and 9) were put in brown iodine determination flasks. The three replicates were analysed with GC after 2.4 h and 5 days. Additionally the hydrolysis of the reference substance acetylsalicylic acid was determined the same way and analysed with HPLC. Mean values and standard deviation were calculated with a programmed pocket calculator (TI SR-51-11). The hydrolysis of the test substance was below 50% independent of the pH. The reference substance acetylsalicylic acid is totally hydrolysed after 5 days at pH 7 and 9. After 5 days at pH 4 0.1% of the start concentration was measured. After 2.4h at pH 4 72.73 % of the start concentration were measured, at pH 7 50.93% and at pH 9 45.60%. The test substance is an arylketone, theoretical no hydrolisation is possible. The test results after 2.4 h exposure in aqueous medium in a decrease in concentration of approx. 10-20%. Since the values are again higher after 5 days it can be assumed that this decline is not due to degradation, but an artifact of the method could be responsible. As the water solubility of the substance is not good, the determination of the concentration is only possible with a relatively large error. The results lead to a DT50 of the test substance in the environment of more than one year.

Description of key information

The hydrolysis of the test substance was determined according to OECD 111. Under the given conditions the DT50 is more than one year (reference 5.2.1-1).

Additional information

The hydrolysis of the test substance was determined according to OECD TG 111. The test substance (400 mg/L) and 50 mL of the buffer solution (pH 4, 7 and 9) were put in brown iodine determination flasks. The three replicates were analysed with GC after 2.4 h and 5 days. Additionally the hydrolysis of the reference substance acetylsalicylic acid was determined the same way and analysed with HPLC. Mean values and standard deviation were calculated with a programmed pocket calculator (TI SR-51-11). The hydrolysis of the test substance was below 50% independent of the pH. The reference substance acetylsalicylic acid is totally hydrolysed after 5 days at pH 7 and 9. After 5 days at pH 4 0.1% of the start concentration was measured. After 2.4h at pH 4 72.73 % of the start concentration were measured, at pH 7 50.93% and at pH 9 45.60%. The test substance is an arylketone, theoretical no hydrolisation is possible. The test results after 2.4 h exposure in aqueous medium in a decrease in concentration of approx. 10-20%. Since the values are again higher after 5 days it can be assumed that this decline is not due to degradation, but an artifact of the method could be responsible. As the water solubility of the substance is not good, the determination of the concentration is only possible with a relatively large error. The results lead to a DT50 of the test substance in the environment of more than one year (reference 5.1.2-1).