Vanadium

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

See "Principles of method if other than guideline"

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

yes

Remarks:

See "Principles of method if other than guideline"

Principles of method if other than guideline:

- Based on experience and in view of the poor solubility of other metal substances (e.g. metal carbonates), the test was conducted under exclusion of atmospheric carbon dioxide and oxygen.
- Two vessels were set up in a parallel design at 20°C ± 1.0°C. Each vessel was sampled several times instead of sampling one vessel at every point in time. This modification helped to avoid weighing errors and enabled sampling up to 8 times.

GLP compliance:

yes (incl. QA statement)

Remarks:

signed, 2007-03-21

Type of method:

flask method

Water solubility:

146.9 µg/L

Conc. based on:

test mat. (dissolved fraction)

Loading of aqueous phase:

110 mg/L

Incubation duration:

72 h

Temp.:

20 °C

pH:

5.8

Remarks on result:

other: mean dissolved vanadium: 146.9 ± 9.0 μg/L

Details on results:

Under the conditions of this test (under exclusion of CO2 and O2 under argon gas; flask method; loading of approx. 110 mg/L), the water solubility of vanadium metal powder at 20.0 ± 1.0°C was determined at 146.9 ± 9.0 µg/L after 72 h (dissolved V measured by ICP-OES, separated by filtration (0.2 µm) from undissolved test material). The resulting solution pH was measured to be approx. 5.8.

Method validation summary (main study)

Validation parameter	results	comment
selectivity	similar data with two different wavelength for ICP-OES method	no interferences observed
linearity	applied calibration functions were linear	correlation coefficient (r) at least 0.9999
limits of detection (LOD)	5.8 - 14 µg/L
limits of quantification (LOQ)	19 - 46 µg/L
blanks	at least below < LOQ = < 19 - < 46 µg/L; n = 24
accuracy and precision	mean recovery for TMDA-70: 101 ± 0.9 % (n = 16)	corresponds to concentration range of samples (312 µg/L)
accuracy and precision	mean recovery for quality control standard: 97.7 ± 1.5 % (n = 16)	corresponds to concentration range of samples (100 µg/L)
accuracy and precision	mean recovery for recalibration: 101 ± 0.7 % (n = 8)	corresponds to concentration range of samples (100 µg/L)
repeatability	recovery from fortification of samples: 99.0 -99.3 % (n = 4)	corresponds to concentration range of samples
reproducibility	recovery for TMDA-70: 102 ± 1.0 % (n = 18)	for concentration range of samples (312 µg/L)
reproducibility	recovery for quality control standard: 97.7 ± 1.5 % (n = 18)	for concentration range of samples (CPI standard diluted to 100 µg/L V)
reproducibility	recovery for recalibration standard 100 µg/L: 101 ± 0.7 % (n = 8)	for concentration range of diluted samples

Measured vanadium concentrations in test samples

stirring time [h]	mean V conc. vessel A [µg/L]	mean V conc. vessel B [µg/L]	mean V conc. [µg/L]	variation [%]
24	143.1 ± 2.4*	162.5 ± 0.8*	152.8 ± 11
48	142.1 ± 3.2*	160.9 ± 0.2*	151.5 ± 11	- 0.85
72	126.8. ± 1.8*	146.3 ± 0.9*	136.5 ± 11	- 9.89
96	108.5 ± 2.8	136.1 ± 1.1	121.8 ± 15	- 10.8

* Values were taken into account for the calculation of the water solubility

Conclusions:

Under the conditions of this test (under exclusion of CO2 and O2 under argon gas; flask method; loading of approx. 110 mg/L), the water solubility of vanadium metal powder at 20.0 ± 1.0 °C was determined at 146.9 ± 9.0 µg/L after 72 h (dissolved V measured by ICP-OES, separated by filtration (0.2 µm) from undissolved test material). The resulting solution pH was measured to be approx. 5.8. Hence, vanadium metal powder may considered as slightly soluble (0.1-100 mg/L).

Reference 2

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-07-20 to 2011-11-09

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

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.:

21.7 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

21 °C, pH 8

Remarks on result:

other: Mean dissolved concentration: 21.7 ± 6.4 µg V/L

Type of test:

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

Mean dissolved conc.:

18.7 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

21 °C, pH 6

Remarks on result:

other: Mean dissolved concentration: 18.7 ± 0.6 µg/L

Key result

Type of test:

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

Mean dissolved conc.:

21.8 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

21 °C, pH 8

Remarks on result:

other: Mean dissolved concentration: 21.8 ± 1.4 μg V/L

Key result

Type of test:

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

Mean dissolved conc.:

23.8 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

21 °C, pH 6

Remarks on result:

other: Mean dissolved concentration: 23.8 ± 0.8 μg V/L

Key result

Type of test:

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

Mean dissolved conc.:

38.4 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

21 °C, pH 8

Remarks on result:

other: Mean dissolved concentration: 38.4 ± 0.7 μg V/L

Key result

Type of test:

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

Mean dissolved conc.:

39.6 µg/L

Element analysed:

Vanadium

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

21 °C, pH 6

Remarks on result:

other: Mean dissolved concentration 39.6 ± 1.5 μg V/L

Details on results:

Measured pHs and oxygen levels as well as mean temperatures of all loadings were in compliance with the requirements of the OECD Series 29. Under the described conditions of this test with vanadium metal powder with three different loadings, dissolved vanadium concentrations were at a
- loading of 1 mg/L V after 7 days 21.8 ± 1.4 μg/L and 23.8 ± 0.8 μg/L at pH 8 and pH 6, respectively
- loading of 1 mg/L V after 28 days 38.4 ± 0.7 μg/L and 39.6 ± 1.5 μg/L at pH 8 and pH 6, respectively
- loading of 10 mg/L V after 7 days 206 ± 5 μg/L and 279 ± 12 μg/L at pH 8 and pH 6, respectively
- loading of 100 mg/L V after 7 days 2406 ± 95 μg/L and 10457 ± 1713 μg/L at pH 8 and pH 6, respectively

The respective limits of 20 % and 10 % for the between-vessel and the within-vessel variation, required by OECD Series 29 were met after 7 and 28 d for all loadings.

At the loading of 1 mg/L, dissolved vanadium was predominantly in the pentavalent form at pH 6 & 8 at all sampling times. Tetravalent V concentrations were below the LOD or the LOQ in nearly all samples. Only in samples from day 14 and 21 at pH 8, tetravalent V was quantified (all < 8 μg/L ). Recoveries of V (IV) and V (V) ranged from 82.3 - 120 %. It can be assumed that trivalent V was not present in any significant amount.

Conclusions:

Measured pHs and oxygen levels as well as mean temperatures of all loadings were in compliance with the requirements of the OECD Series 29. Under the described conditions of this test with vanadium metal powder with three different loadings, dissolved vanadium concentrations were at a
- loading of 1 mg/L V after 7 days 21.8 ± 1.4 μg/L and 23.8 ± 0.8 μg/L at pH 8 and pH 6, respectively
- loading of 1 mg/L V after 28 days 38.4 ± 0.7 μg/L and 39.6 ± 1.5 μg/L at pH 8 and pH 6, respectively
- loading of 10 mg/L V after 7 days 206 ± 5 μg/L and 279 ± 12 μg/L at pH 8 and pH 6, respectively
- loading of 100 mg/L V after 7 days 2406 ± 95 μg/L and 10457 ± 1713 μg/L at pH 8 and pH 6, respectively

The respective limits of 20 % and 10 % for the between-vessel and the within-vessel variation, required by OECD Series 29 were met after 7 and 28 d for all loadings.

At the loading of 1 mg/L, dissolved vanadium was predominantly in the pentavalent form at pH 6 & 8 at all sampling times. Tetravalent V concentrations were below the LOD or the LOQ in nearly all samples. Only in samples from day 14 and 21 at pH 8, tetravalent V was quantified (all < 8 μg/L ). Recoveries of V (IV) and V (V) ranged from 82.3 - 120 %. It can be assumed that trivalent V was not present in any significant amount.

Description of key information

Water solubility of vanadium under O2 and CO2 exclusion, loading of approx. 110 mg/L: 146.9 ± 9.0 µg/L at 20 °C (pH 5.8)

In a transformation/dissolution test with vanadium metal powder, dissolved vanadium concentrations were at a loading of 1 mg/L:

- after 7 days 21.8 ± 1.4 μg V/L and 23.8 ± 0.8 μg V/L at pH 8 and pH 6, respectively, and

- after 28 days 38.4 ± 0.7 μg V/L and 39.6 ± 1.5 μg V/L at pH 8 and pH 6, respectively.

Key value for chemical safety assessment

Water solubility:

146.9 µg/L

at the temperature of:

20 °C