Copper dibromide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-12-03 to 2018-12-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Determination of the solubility in water of Cupric Bromide according to OECD 105 resp. EU A.6 and under GLP conditions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

GLP compliance:

yes (incl. QA statement)

Remarks:

2018-08-15

Type of method:

flask method

Specific details on test material used for the study:

- Molecular formula: CuBr2
- Molecular weight: 223.35 g/mol

Key result

Water solubility:

1 068 g/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

0

Remarks on result:

other: The determination of the pH was not possible due to a very dark colour of the test item solution (pH paper was discoloured)

Conclusions:

The water solubility of Cupric Bromide was stated as 1068 ± 77 g/L with the relative standard deviation of 7.2 %.

Executive summary:

The solubility in water of the registered substance cupric dibromide was determined in an experimental study performed according to OECD 105 resp. EU A.6 and under GLP conditions.

The solubility of the test item in water was determined by measurement of the copper (Cu) concentration in the filtrated test solutions using ICP-OES. The concentration of the test item was calculated from the measured Cu concentrations and the Cu content in the test item. For the calibration, a dilution series in demineralised water was prepared using a stock solution. The method was validated for the parameters specificity, linearity, accuracy, precision and limits of detection and quantification (LOD and LOQ).

In the preliminary test, the concentration of Cu was stated as > 1000 g/L. Therefore, the highest possible nominal load 3333 g/L was determined and used in the main test.

According to the guideline, the flask method was used for the determination of the solubility of the test item in water.

In the main test, six replicates were prepared (flasks 1A, 1B, 1C and 2 – 4). As the nominal concentration of five times of the quantity, necessary for saturation (as determined in the pre-test) was not possible and resulted in non-filterable mixtures, the highest possible nominal load determined in the preliminary test 3333 g/L was used (deviation from the guidelines). All replicates were prepared with the same loading rate. Four vessels (flasks blank, 1C (for the sampling point 72 h) and 2 – 4) were set onto the shaking apparatus immediately. After 24 ± 2 hours, flask 1B (for the sampling point 48 h) and after 48 ± 2 hours, flask 1A (for the sampling point 24 h) were set on the shaker and all flasks were shaken for further 24 ± 2 hours at room temperature. Then, flasks 1A-C were taken from the shaker, tempered at 20.0 ± 0.5 °C, samples were taken, filtrated and prepared for Cu analysis via ICP-OES. Due to a difference more than 15 % in the concentrations on days 2 and 3 (flasks 1B and 1C), the test was prolonged and flask 1C was measured on days 4 and 5. Because of a difference of less than 15 % in the concentrations on days 4 and 5 and no upward tendency, the test was finished on day 5.

Due to a very dark colour of the filtrated test item solutions the determination of Tyndall effect was not possible (no laser beam was visible).

All values were taken into account in the calculation of the mean except the concentration in flask 1C (3 d) which was stated as an outlier (Grubbs’ outlier test). 

The concentration of Cupric Bromide in water was stated as: 1068 ± 77 g/L at 20.0 ± 0.5 °C = 1068 ± 77 kg/m3 (SI units) (mean value ± standard deviation of six individual vessels). No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

Description of key information

The water solubility of Cupric Bromide was stated as 1068 ± 77 g/L with the relative standard deviation of 7.2 %.

Key value for chemical safety assessment

Water solubility:

1 068 g/L

at the temperature of:

20 °C