N-(4-amino-9,10-dihydro-3-methoxy-9,10-dioxo-1-anthryl)benzenesulphonamide

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016

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)

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 12-45 (China)
- Expiration date of the lot/batch: 05 March 2019

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature in the dark

Analytical monitoring:

yes

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 sample solution were diluted

Standards
Duplicate standard solutions of test item were prepared in DMSO: relevant buffer solution (25:75 v:v) at a nominal concentration of 0.53 mg/L.

Matrix blanks
DMSO: relevant buffer solution (25:75 v:v)

Buffers:

The test system used sterile buffer solutions at pH’s 4, 7 and 9

Specification of the Buffer Solutions
Buffer Solution (pH) Components Concentration

4 Citric acid 0.006
Sodium chloride 0.004
Sodium hydroxide 0.007
7 Disodium hydrogen orthophosphate (anhydrous) 0.003
Potassium dihydrogen orthophosphate 0.002
Sodium chloride 0.002
9 Disodium tetraborate 0.001
Sodium chloride 0.002

These solutions were subjected to ultrasonication, filtration through 0.2 μm filters and degassing with nitrogen to minimize dissolved oxygen content.

Duration:

120 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

0.7 mg/L

Remarks:

The extent of hydrolysis after 120 hours indicated that further tests (Tier 2), conducted at 50 ± 0.5°C, 60 ± 0.5°C and 70 ± 0.5 °C, were required to estimate the rate constant and half-life at 25 °C.

Duration:

120 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

0.7 mg/L

Remarks:

Less than 10% hydrolysis after 5 days at 50.0 ± 0.5 °C, equivalent to a half-life of greater than 1 year at 25 °C.

Duration:

120 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

0.7 mg/L

Remarks:

The extent of hydrolysis after 120 hours indicated that further tests (Tier 2), conducted at 50 ± 0.5°C, 60 ± 0.5°C and 70 ± 0.5 °C, were required to estimate the rate constant and half-life at 25 °C.

Duration:

432 h

pH:

4

Temp.:

50 °C

Duration:

264 h

pH:

4

Temp.:

60 °C

Duration:

264 h

pH:

4

Temp.:

70 °C

Duration:

480 h

pH:

9

Temp.:

50 °C

Duration:

360 h

pH:

9

Temp.:

60 °C

Duration:

240 h

pH:

9

Temp.:

70 °C

Positive controls:

no

Negative controls:

no

Statistical methods:

None

Transformation products:

not specified

pH:

4

Hydrolysis rate constant:

0

DT50:

> 1 yr

Adsorption Coefficient (Koc). 2.17 x 104, log10Koc 4.34, using the HPLC screening method, designed to be compatible with Method C19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001. These values indicate that the test item will be immobile in the environment.

Validity criteria fulfilled:

not specified

Conclusions:

The estimated half-life at pH 4, 7 and 9 at 25 °C was >1 year.

Executive summary:

The determination of hydrolysis as a function of pH for FAT 36034/H was carried out in a study conducted according to OECD Guideline 111. In the preliminary test, sample solutions were prepared at a nominal concentration of 0.7 mg/L at pH 4, 7 and 9 and maintained at 50.0 ± 0.5 °C for a period of 120 hours. The preliminary testing at pH 4 and 9 demonstrated 54 and 79 % hydrolysis at 120 hours (for pH 4 and pH 9 respectively), therefore Tier 2 testing was required. In addition the preliminary testing for pH 7 was conducted twice in order to conclude if there was less than 10% hydrolysis as the margin was very close, it was however, established that the hydrolysis was less than 10 % and no tier 2 testing was required. The Tier 2 testing for pH 4 produced an overall half-life of 501 days which was greater than 1 year. The results for pH 9 also showed no significant hydrolysis at any of the temperatures, and therefore a limit value of 1 year reported for pH 9 as well.

Description of key information

The estimated half-life at pH 4, 7 and 9 at 25 °C was >1 year.

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

25 °C

Additional information

The determination of hydrolysis as a function of pH for FAT 36034/H was carried out in a study conducted according to OECD Guideline 111. In the preliminary test, sample solutions were prepared at a nominal concentration of 0.7 mg/L at pH 4, 7 and 9 and maintained at 50.0 ± 0.5 °C for a period of 120 hours. The preliminary testing at pH 4 and 9 demonstrated 54 and 79 % hydrolysis at 120 hours (for pH 4 and pH 9 respectively), therefore Tier 2 testing was required. In addition the preliminary testing for pH 7 was conducted twice in order to conclude if there was less than 10% hydrolysis as the margin was very close, it was however, established that the hydrolysis was less than 10 % and no tier 2 testing was required. The Tier 2 testing for pH 4 produced an overall half-life of 501 days which was greater than 1 year. The results for pH 9 also showed no significant hydrolysis at any of the temperatures, and therefore a limit value of 1 year reported for pH 9 as well.