Dibismuth trioxide

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2010-01-18 till 2010-01-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed by Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht Land Rheinland Pfalz (2007-01-11)

Type of method:

column elution method

Water solubility:

5.887 mg/L

Temp.:

21.3 °C

pH:

6

Remarks on result:

other: Measurements at flow rate 23.45 mL/hour. A standard deviation of 0.471 mg/L was calculated.

Water solubility:

0.777 mg/L

Temp.:

21.3 °C

pH:

6

Remarks on result:

other: Measurements at flow rate 12.33 and 6.15 mL/hour. A standard deviation of 0.0732 mg/L was calculated.

Details on results:

Mean at the plateau (5 measured samples) at the flow rate 23.45 ml/hour is 5.887 +/- 0.471 mg/L.
Mean at the plateau (11 measured samples) at the two last flow rates (12.33 and 6.15 mL/hour) is 0.777 +/- 0.0732 mg/L.

Conclusions:

Interpretation of results (migrated information): slightly soluble (0.1-100 mg/L)
The samples showed poor correspondence. At flow rate 23.45 mL/hour, solubility of Dibismuth trioxide was 5.887 +/- 0.471 mg/L. In contrast, at flow rates 12.33 and 6.15 mL/hour, solubility lay at 0.777 +/- 0.0732 mg/L.

Executive summary:

In a preliminary study, the solubility of the test item in water was estimated as <10 mg/L.

Following the guideline OECD 105 and EEC A.6 respectively the colum elution method was used to determine the solubility of Dibismuth trioxide in water. 5.2g of the test item was filled into the column.

A flow rate of 23.45 mL/hour was set. After discarding about 10 column volumes, fractions were collected and measured. After 5 consecutive fractions, the plateau was considered as reached, because variation was less than 30% and no upward tendency was observed.

A second run with a flow rate of 12.33 mL/hour was performed likewise. After 5 consecutive fractions with variation <30% and no upward tendency, a third run with a flow of approximately 6.15 mL/hour was performed and was finished after six consecutive fractions.

The difference of concentrations measured for both last flow rates only is much smaller than 30%, therefore independency of solubility and flow rate is not given.

At flow rate 23.45 mL/hour the concentration of Dibismuth trioxide in water had reached: 5.887 +/- 0.471 mg/L at 21.3 +/- 0.3°C = 5.887*10 ^-3 kg/m³ (SI units) (mean value of 5 fractions). At flow rates 12.33 and 6.15 mL/hour the concentration of Dibismuth trioxide in water had reached: 0.777 +/- 0.0732 mg/L at 21.3 +/- 0.4°C = 77.7 *10 ^-4 kg/m³ (SI units) (mean value of 11 fractions).

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

18 August 2014 to 7 October 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study conducted in accordance with EU and OECD Guidelines

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Water solubility:

< 0.02 mg/L

Temp.:

20 °C

pH:

6.1

Details on results:

The data of the fractions 1 to 5 were not taken into account for the following evaluation. The values for the water solubility were calculated from fractions 39 to 43 for column 1 and from the fractions 86 to 90 for column 2. The measured bismuth concentration was converted into the water solubility of the test item under the assumption that bismuth was present in the form of 13.-Bismuth oxide (Bi content: 89.4 %).

At the end of the study it was confirmed that residual test item remained on the columns. An optical inspection showed considerable yellow coloured columns.

As blank value the used distilled water was tested by means of ICP-OES. The measured concentration of bismuth was below the detection limit of 0.02 mg/L.

In column 1 and 2 the concentration of five consecutive fractions was constant within ± 30 %. No increasing or decreasing tendency was observed.

The water solubility cs of the test item (mean value of column 1 and column 2) was < 0.02 mg/L.

Column 1:

Rotation period of the fraction collector: 90 min per fraction

Duration of sampling: about 72 h (48 fractions)

 

Table 1: Column elution method, column 1

Fraction no.	V in ml	pH	Measured Bi concentration in mg/L	water solubility in mg/L
39	12.0	6.0	<0.02	<0.02
40	11.8	6.0	<0.02	<0.02
41	11.8	6.1	<0.02	<0.02
42	11.7	6.2	<0.02	<0.02
43	11.7	6.2	<0.02	<0.02

Evaluation of the fractions 39 to 43:

The water solubility was found to be < 0.02 mg/L.

Column 2:

Rotation period of the fraction collector: 45 min per fraction

Duration of sampling: about 72 h (96 fractions)

Table 2: Column elution method, column 2

Fraction no.	V in ml	pH	Measured Bi concentration in mg/L	water solubility in g/L
86	7.9	6.1	<0.02	<0.02
87	7.9	6.1	<0.02	<0.02
88	7.8	6.0	<0.02	<0.02
89	7.7	5.8	<0.02	<0.02
90	7.7	6.0	<0.02	<0.02

Evaluation of the fractions 86 to 90:

The water solubility was found to be < 0.02 mg/L.

Conclusions:

Interpretation of results (migrated information): insoluble (< 0.1 mg/L)
The water solubility of the test item at 20 degrees C was determined to be < 0.02 mg/L.

Executive summary:

The water solubility of the test item at 20 degrees C was determined to be < 0.02 mg/L.

Description of key information

Water solubility of dibismuth trioxide: slightly soluble (study results, according to OECD guideline 105)

Key value for chemical safety assessment

Water solubility:

5.887 mg/L

at the temperature of:

21.3 °C

Additional information

The water solubility of the dibismuth trioxide (this is the alpha form of the substance) was determined with the column elution method a three different flow rates: At flow rate 23.45 mL/hour the concentration of dibismuth trioxide in water had reached: 5.887 +/- 0.471 mg/L at 21.3 +/- 0.3°C (mean value of 5 fractions) . At flow rates 12.33 and 6.15 mL/hour the concentration of dibismuth trioxide in water had reached: 0.777 +/- 0.0732 mg/L at 21.3 +/- 0.4°C (mean value of 11 fractions).

The water solubility of beta-dibismuth trioxide was determined with the column elution method. The water solubility was determined to be < 0.02 mg/L at 20 degrees C.