Vanadium oxide sulphate

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-05-19 to 2011-08-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Series on Testing and Assessment No. 29 (23-Jul-2001): Guidance document on transformation/dissolution of metals and metal compounds in aqueous media

Version / remarks:

2001

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed on 2011-02-07

Type of method:

flask method

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

303 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 other: mg test item/L

Incubation duration:

1 d

Test conditions:

pH 6.0, 21.0 °C

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

305 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 other: mg test item/L

Incubation duration:

1 d

Test conditions:

pH 8.0, 21.0 °C

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

212 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 other: mg test item/L

Incubation duration:

28 d

Test conditions:

pH 6.0, 21.0 °C

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

211 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 other: mg test item/L

Incubation duration:

28 d

Test conditions:

pH 8.0, 21.0 °C

Details on results:

Under the described conditions of this test with vanadium oxide sulphate at a loading of 1 mg/L, dissolved vanadium concentrations after 28 days were 211 ± 6 μg/L and 212 ± 2 μg/L at pH 8 and pH 6, respectively. Measured concentrations indicate a complete dissolution of the test item in both media. Over the course of the test only pentavalent vanadium species were detectable.

Vanadium oxide sulphate was completely dissolved after 2 hours in both media (pH 6 & pH 8). The decrease of measured vanadium concentrations over time is due to dilution, i.e. removal of vanadium by sampling and replacing the sampled test media (i.e., 150 ml fresh media after 24h and respectively 50 mL at every subsequent sampling) in accordance with the guidance document. Normalizing dissolved V concentrations for vanadium removed by sampling indicates
that at any sampling time, all vanadium in the test vessels was completely dissolved. Recovery of total dissolved vanadium when expressed as the sum of measured dissolved tetra- and pentavalent vanadium species ranged from 76.9 to 121%.

The within and between vessel variation, the variation of mean V concentrations
between sampling intervals as well as pH, temperatures and oxygen levels meet the requirements of the OECD-Guidance document 29. Therefore the OECD 29 is regarded to be fulfilled.

Conclusions:

Under the described conditions of this test with vanadium oxide sulphate at a loading of 1 mg/L, dissolved vanadium concentrations after 28 days were 211 ± 6 μg/L and 212 ± 2 μg/L at pH 8 and pH 6, respectively. Measured concentrations indicate a complete dissolution of the test item in both media. Over the course of the test only pentavalent vanadium species were detectable.

Vanadium oxide sulphate was completely dissolved after 2 hours in both media (pH 6 & pH 8).

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-09-01 to 2011-10-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Deviations:

no

GLP compliance:

no

Type of method:

flask method

Water solubility:

467 g/L

Conc. based on:

test mat. (total fraction)

Incubation duration:

<= 72 h

Temp.:

20 °C

pH:

>= 0.81 - <= 1.07

Conclusions:

Interpretation of results: very soluble (> 10000 mg/L)
Vanadium oxide sulphate has a water solubility of 467 g/L at 20 °C and pH 0.81 - 1.07.

Description of key information

- Water solubility: 457.0 g/L

- Transformation dissolution: 211 ± 6 μg/L and 212 ± 2 μg/L at pH 8 and pH 6 after 28 days

Key value for chemical safety assessment

Water solubility:

467 g/L

at the temperature of:

20 °C

Additional information

Seagrave, Julien, 2012:

The water solubility of Vanadium oxide sulphate is 467 g/L at 20 °C with a pH 0.81 - 1.07.

Klawonn, 2011:

In a transformation dissolution test with vanadium oxide sulphate at a loading of 1 mg/L, dissolved vanadium concentrations after 28 days were 211 ± 6 μg/L and 212 ± 2 μg/L at pH 8 and pH 6, respectively. Measured concentrations indicate a complete dissolution of the test item in both media. Over the course of the test only pentavalent vanadium species were detectable. Vanadium oxide sulphate was completely dissolved after 2 hours in both media (pH 6 & pH 8).