Bis(5-oxo-L-prolinato-N1,O2)zinc

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 November 2016 to 08 November 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

See below

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

yes

Remarks:

See below

Principles of method if other than guideline:

The guideline specifies that the test item in excess should be added to water however the physical properties of the test item do not permit this. The study method therefore deviates from the guideline but is considered scientifically valid.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

94 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

100 g/L

Incubation duration:

10 min

Temp.:

20 °C

pH:

> 4.63 - < 4.64

Details on results:

Based on the measured concentrations the test mixtures were homogeneous and the whole amount of the added test substance was dissolved.
The water solubility of the test material was greater than 94.0 g/L at 20 ± 0.5 °C.

Table 1: Results of the determination of the test item concentrations

Nominal Conc. mg/mL	pH	Calculated concentration mg/mL	Mean g/L
98.3	4.63	92.1	94.0
		95.9
95.4	4.64	100.2	97.2
		94.3
95.7	4.64	98.8	100.9
		103.0

Conclusions:

As the measured concentrations correspond to the total dissolution of the test substance, and also based on the justification measurement, the water solubility of the test material is higher than 94.0 g/L at 20 ± 0.5 °C.

Executive summary:

The water solubility of the test material was investigated in accordance with the standardised guideline OECD 105 and EU Method A.6.

As the expected water solubility is above 10^-2 g/L, the flask method was applied.

About 2.0 g of test item was weighed into Erlenmeyer flasks. After addition of 20 mL water, the mixtures were stirred for 10 minutes. Three parallel solutions were made. The density of the test solutions was 1.05 g/mL (mean of three replicates).

After stirring the flasks were removed and the concentration in the clear solvent phase was determined by HPLC. The pH of each sample was recorded.

Before the HPLC analysis, samples were diluted in two consecutive steps. Two replicate dilutions were carried out using water.

Based on the measured concentrations, the test mixtures were homogeneous and the whole amount of the added test substance was dissolved.

As the measured concentrations correspond to the total dissolution of the test substance, and also based on the justification measurement, the water solubility of the test material is higher than 94.0 g/L at 20 ± 0.5 °C.

Description of key information

As the measured concentrations correspond to the total dissolution of the test substance, and also based on the justification measurement, water solubility of the test material is higher than 94.0 g/L at 20 ± 0.5 °C.

Key value for chemical safety assessment

Water solubility:

94 g/L

at the temperature of:

20 °C

Additional information

The water solubility of the test material was investigated in accordance with the standardised guideline OECD 105 and EU Method A.6. The study was assigned a reliability score of 1 in accordance with the criteria for assessing data quality set forth by Klimisch et al. (1997).

As the expected water solubility is above 10^-2 g/L, the flask method was applied.

About 2.0 g of test item was weighed into Erlenmeyer flasks. After addition of 20 mL water, the mixtures were stirred for 10 minutes. Three parallel solutions were made. The density of the test solutions was 1.05 g/mL (mean of three replicates).

After stirring the flasks were removed and the concentration in the clear solvent phase was determined by HPLC. The pH of each sample was recorded.

Before the HPLC analysis, samples were diluted in two consecutive steps. Two replicate dilutions were carried out using water.

Based on the measured concentrations, the test mixtures were homogeneous and the whole amount of the added test substance was dissolved.

As the measured concentrations correspond to the total dissolution of the test substance, and also based on the justification measurement, the water solubility of the test material is higher than 94.0 g/L at 20 ± 0.5 °C.