Bismuth hydroxide nitrate oxide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 January 2010 to 29 January 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in accordance with EU and OECD guidelines and in compliance with GLP.

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:

Deviation from the Guideline: Deionised water was used for the determination of the solubility in water of Bismuth hydroxide nitrate oxide, instead of doubly distilled water, as the validation showed, that the usage of deionised water was acceptable for the determination of the solubility in water of Bismuth compounds. This is considered as uncritical concerning the outcome of the study.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Water solubility:

900.7 mg/L

Temp.:

20 °C

Remarks on result:

other: Standard deviation of all samples was 113.8 mg/L

Details on results:

All replicates showed very good correspondence. Standard deviation of all samples was 113.8 mg/L, corresponding to a relative standard deviation of 12.8%.
Equilibration time can be considered as < 24 hours, as the values which were measured on consecutive days did not give significantly different values.
Accuracy measurements via standard addition showed a correlation of 0.995, indicating that no matrix effects were present.
No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

Measurements during Equilibration

The data which was acquired during equilibration is presented in the following table:

Day	Flask	Temperature in °C	pH	Dilution factor	Bi Concentration in mg/L	Difference to previous sam­ple
1	1	20	3	1010	0.620	-
2	1	20	3	1010	0.650	+ 4.8%
3	1	20	3	1010	0.605	- 7.0 %

After the analysis of the sample of day 3, the plateau was considered as reached.

Measurements at Plateau

The following table gives the values which were measured at the plateau:

Flask	2	3	4	5	6
pH	2.78	2.68	2.68	2.77	2.60
Concentration Bi in mg/L (diluted sample)	0.768	0.654	0.511	0.718	0.573
Dilution factor	1010	1010	1010	1010	1010
Concentration Bi in mg/L (original sample)	775.6	660.9	516.4	724.9	578.4
Factor (Bi/test item)	0.41471	0.41471	0.41471	0.41471	0.41471
Concentration test item in mg/L	1085.2	924.7	722.5	1014.3	809.3

All measurements of the days 1 - 3 were included in the calculation of the mean since the differences between the measured concentrations lay below 15%:

Day	Mean Conc. (mg/L)	Total Mean (mg/L)	Total Stand. Dev.
1	876.5	900.7 mg/L	113.8 mg/L (12.8%)
2	918.9
3	854.6
3	1085.2
3	924.7
3	722.5
3	1014.3
3	809.3

 

Conclusions:

Interpretation of results (migrated information): moderately soluble (100-1000 mg/L)
Using the flask method, at the plateau, the concentration of Bismuth subnitrate in water had reached 900.7 ±113.8 mg/L at 20 ± 0.5 °C (mean value ± standard deviation of six individual vessels) 

Executive summary:

In a pre-test, solubility was believed to lie below 10 mg/L. Therefore, the column elution method was employed. The results of the measurements of the fractions showed, though, that solubility was far above 10 mg/L. The experiment was aborted, and solubility was determined using the flask method. The results of the column elution method are not reported.

For the flask method, 11000 - 13000 mg/L were weighed into each of six individual vessels, water was added, and the vessels were shaken at 20 ± 1.7 °C.

On the days 1, 2, and 3, vessel 1 was taken from the shaking apparatus and stored at 20 ± 0.5 °C for equilibration. Samples were taken, centrifuged or filtrated and analysed using AAS as shaking of the test vessels was continued.

No differences above 15% in the concentration of the solution could be determined between the sampling dates 1, 2, and 3, supporting the hypothesis, that the maximum concentration of the test item had been reached. Therefore, on day 3, vessels 2-5 were sampled and analysed in the same fashion.

At the plateau, the concentration of Bismuth subnitrate in water had reached 900.7 ±113.8 mg/L at 20 ± 0.5 °C (mean value ± standard deviation of six individual vessels) 

Description of key information

The water solubility of bismuth subnitrate is 900.7 mg/L.

Key value for chemical safety assessment

Water solubility:

900.7 mg/L

at the temperature of:

20 °C

Additional information

A study was conducted to determine the water solubility of bismuth subnitrate in accordance with OECD Guideline 105 and EU Method A.6.

Using the flask method, at the plateau, the concentration of bismuth subnitrate in water had reached 900.7 ±113.8 mg/L at 20 ± 0.5 °C (mean value ± standard deviation of six individual vessels)