Oxo(propan-2-olato)aluminium

Water solubility

Administrative data

Endpoint:

water solubility

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is hydrolytically unstable at pH 4, 7 and 9 (half-life less than 12 hours)

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27-Feb-17 to 26-Apr-17.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

not specified

Principles of method if other than guideline:

The objective of the study was to estimate the solubility in water and to assess fast hydrolysis
at 3 pHs (i.e. acidic, neutral and basic: about pH 4 to 9) of the test item.

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

Hydrolysis tests were performed at 20 ± 0.5°C until at least 80 % or more of the test item
were hydrolyzed. Hydrolysis was examined in demineralized water and in aqueous buffer
solutions at pH 4, 7 and 9. Aliquots of the hydrolysis system were collected at several time
points and analysed immediately by HS-GC-MS to follow the formation of the expected
hydrolysis product 2-propanol. Analysis of the intact test item complex was considered not
possible.

Buffers:

Aqueous buffer solutions were prepared as follows:
pH 4 (0.05 M) Citrate Buffer: 23 g of potassium dihydrogen citrate was dissolved in 1 L of water. An aliquot of 0.50 L was mixed with 0.09 L of 0.1 M NaOH and filled up with water to 1 L to give a pH of 4.
pH 7 (0.05 M) Phosphate Buffer: 13.6 g of potassium dihydrogen phosphate was dissolved in 1 L of water. An aliquot of 0.50 L was mixed with 0.296 L of 0.1 M NaOH and filled up with water to 1 L to give a pH of 7.
pH 9 (0.05 M) Borate Buffer: 19 g of sodium tetraborate decahydrate were dissolved in 1 L of water. An aliquot of 0.85 L was mixed with 0.15 L of 0.1 M HCl (prepared from 10 M HCl, Merck,
32 %) to give a pH of 9.

Details on test conditions:

Generally 25 μL of the spike solution (10 mg/mL XP 473) were diluted in a final volume of
250 mL of buffer solution or demineralized water in glass bottles and shaken vigorously or in
other volumes by considering the volume ratio. The resulting concentration of the substance was
1.0 mg/L (approx. 10 -5 mol/L).
Two replicate test solutions were prepared for water and each buffer solution.
Aliquots of the test solutions (2.0 mL) were transferred into individual autosampler vials.
These aliquots were measured with HS-GC-MS without delay.

Duration:

49 min

pH:

7

Temp.:

20 °C

Initial conc. measured:

1 mg/L

Remarks:

Substance dosed as 10 mg/mL solution in DMSO: e.g 0.05 mL (0.5 mg) added to 0.5 L of buffer,
resulting in an initial concentration of 1 mg substance / L of buffer. Ca 8% remaining after 2 min.

Duration:

76 min

pH:

4

Temp.:

20 °C

Initial conc. measured:

1 mg/L

Remarks:

Substance dosed as 10 mg/mL solution in DMSO: e.g 0.025 mL (0.25 mg) added to 0.25 L of buffer
sample, resulting in an initial concentration of 1 mg XP473 / L of buffer. Ca. 9% remaining after 4 min.

Duration:

49 min

pH:

9

Temp.:

20 °C

Initial conc. measured:

1 mg/L

Remarks:

XP473 dosed as 10 mg/mL solution in DMSO: e.g 0.05 mL (0.5 mg) added to 0.5 L of buffer sample,
resulting in an initial concentration of 1 mg XP473 / L of water/buffer. Ca. 5% remaining after 2 min.

Number of replicates:

2

Positive controls:

no

Negative controls:

no

Transformation products:

yes

No.:

#1

Key result

pH:

4

Temp.:

20 °C

DT50:

< 2 min

Key result

pH:

7

Temp.:

20 °C

DT50:

< 2 min

Type:

not specified

Key result

pH:

9

Temp.:

20 °C

DT50:

< 2 min

Type:

not specified

Validity criteria fulfilled:

yes

Remarks:

Mean accuracies were in the acceptable range from 105 % to 103 % of the expected nominal values.

Conclusions:

Within the first three minutes more than 80 % of the amount of test item dosed was already
hydrolysed to form 2-propanol. The half-life of the test item is estimated to be shorter than 2
minutes in demineralised water and in the pH 4, pH 7 and pH 9 aqueous buffer solutions.

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

Oxo(propan-2-olato)aluminium

EC Number:

270-365-0

EC Name:

Oxo(propan-2-olato)aluminium

Cas Number:

68425-65-0

Molecular formula:

C3 H7 Al O2

IUPAC Name:

oxo(propan-2-olato)aluminium

Test material form:

solid: particulate/powder