Copper, diamminebis(nitrato-kO)

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Prior to the water solubility test, an analytical method has been developed to study the behaviour of the substance in aqueous solution. Indeed, according to available data, CDDN in contact with water decomposes into ammonium, nitrate and copper hydroxide which in turn converted in copper oxide as function of the pH. Both copper oxide and hydroxide are not soluble in wter; consequently, only nitrate and ammonium could be analysed.
The present study consists in verifying CDDN solubility by analysis of its potential dissociation products (copper and ammonia) after solubilisation of CDDN in aqueous solution.
If the substance can remain in aquous solution without dissociation, copper can be analysed by ICP-OES in the dissolved phase, while it will not be possible to analyse nitrate and ammonia by ionic chromatography.
Conversely, if the substance dissociates quickly in aqueous solution, copper should be in the solid phase. It will not be possible to analyse copper by ICP-OES in the dissolved phase. In case of dissociation of the substance, ammonia can be analysed by ionic chromatography.
Analyses of copper and ammonia will allow to know the behaviour of CDDN in solution. In case CDDN dissociates in aqueous solution, the kinetics of dissociation will be studied by analyses of the products of dissociation in solution after different times of solubilisation.

GLP compliance:

no

Type of method:

other: not indicated

Test material

Test material information

Constituent 1

Reference substance name:

Copper, diamminebis(nitrato-kO)

EC Number:

604-942-9

Cas Number:

15414-04-7

Molecular formula:

CuH6N4O6

IUPAC Name:

Copper, diamminebis(nitrato-kO)

Results and discussion

Water solubility

Key result

Remarks on result:

not determinable because of methodological limitations

Remarks:

the substance is not stable is water and dissociates very quickly.

Details on results:

See Tables 1-5 of the joint document:
For ammonia, around 80 % ammonia are very quickly solubilized for all the concentrations. This solubilisation rate is stable and there is no evolution of this solubilisation with the time.
For copper, the percentage of the dissolved copper decreases in function of the concentration. More than 50 % of copper are solubilized at the low concentration (approximately 1 mg/L). Less than 5 % of copper are solubilized at the upper concentrations of 100 mg/L, 1 g/L and 10 g/L.
The immediate presence of ammonia in solution reflects the dissociation of the CDDN substance in solution.
At the three highest concentrations there is no dissolved copper in solution. In contact with water, CDDN is dissociated and copper precipitate in solid phase. Only less than 5 % can be analysed as dissolved copper.
The behavior of copper is more complex at the two lowest concentrations. It appears that between 55 % and 95 % of Cu can be analysed as dissolved copper in the aqueous solutions with 1 mg/L of CDDN. For the aqueous solutions with 10 mg/L of CDDN, between 9% and 25 % of Cu can be analysed as dissolved copper.

Applicant's summary and conclusion

Conclusions:

This results, particularly from the ammonia analysis, shows the dissociation of the CDDN substance in solution. This dissociation appears very quickly.
There is no possibilities to find a specific analytical method for the CDDN substance in aqueous solution. Water solubility study can then not be performed.