Ammonium trivanadium octaoxide

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:

180 mg/L

Conc. based on:

test mat. (dissolved fraction)

Loading of aqueous phase:

2 g/L

Incubation duration:

72 h

Temp.:

20 °C

pH:

3.9

Remarks on result:

other: mean dissolved ammonium trivanadium octaoxide

Water solubility:

94.9 mg/L

Conc. based on:

element (dissolved fraction)

Remarks:

Vanadium

Loading of aqueous phase:

2 g/L

Incubation duration:

72 h

Temp.:

20 °C

pH:

3.9

Remarks on result:

other: mean dissolved vanadium

Details on results:

Under the conditions of this test (under exclusion of CO2 and O2 under argon gas; flask method; loading of 2 g/L), the water solubility of ammonium trivanadium octaoxide at 20.0 ± 0.5°C was determined at 180 ± 3.2 mg/L after 72 h (dissolved V measured by ICP-OES, separated by filtration (0.2 µm) and subsequent centrifugation from undissolved test material). The resulting solution pH was measured to be approx. 3.9.

Method validation

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)	6.5 - 17 µg/L
limits of quantification (LOQ)	22 - 56 µg/L
blanks	at least below < LOQ = < 22 - < 56 µg/L;
accuracy and precision	mean recovery for TMDA-70: 104 ± 2.7 % (n = 28)	corresponds to low concentration range of samples (312 µg/L)
accuracy and precision	mean recovery for quality control standard: 99.0 ± 1.7 % (n = 14)	corresponds to concentration range of diluted samples (500 µg/L)
accuracy and precision	mean recovery for recalibration: 101 ± 0.8 % (n = 9)	corresponds to concentration range of diluted samples (500 µg/L)
repeatability	recovery from fortification of samples: 106 -111 % (n = 4)	corresponds to concentration range of diluted samples
reproducibility	recovery for TMDA-70: 104 ± 2.7 % (n = 28)	for concentration range of diluted samples (312 µg/L)
reproducibility	recovery for quality control standard: 99.0 ± 1.7 % (n = 14)	for concentration range of diluted samples (CPI standard diluted to 100 µg/L V)
reproducibility	recovery for recalibration standard 100 µg/L: 101 ± 0.8 % (n = 9)	for concentration range of diluted samples

Measured vanadium concentrations in test samples

stirring time [h]	dilution	mean V conc. vessel A [µg/L]	mean V conc. vessel B [µg/L]	mean V conc.[µg/L]	variation [%]
24	1:40	81.9 ± 0.2	82.2 ± 0.3	82.3 ± 0.5
48	1:40	86.8 ± 0.12	89.6 ± 0.2	88.2 ± 2.0	+ 7.20
72	1:40	97.0 ± 0.5*	94.3 ± 0.4*	95.7 ± 1.9	+ 8.44
96	1:40	95.1 ± 0.2*	93.0 ± 0.3*	94.0 ± 1.5	- 1.71

*values used for the calculation of the water solubility of the test item

Conclusions:

Under the conditions of this test (under exclusion of CO2 and O2 under argon gas; flask method; loading of 2 g/L), the water solubility of ammonium trivanadium octaoxide at 20.0 ± 0.5 °C was determined at 180 ± 3.2 mg/L after 72 h (dissolved V measured by ICP-OES, separated by filtration (0.2 µm) and subsequent centrifugation from undissolved test material). The resulting solution pH was measured to be approx. 3.9. Hence, ammonium trivanadium octaoxide may considered as moderately soluble (100-1000 mg/L).

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting 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

Water solubility:

260 mg/L

Temp.:

20 °C

pH:

4

Conclusions:

Interpretation of results: moderately soluble (100-1000 mg/L)
The test item has a water solubility of 260 mg/L at 20°C and pH 4.0.

Description of key information

The water solubility of ammonium trivanadium octaoxide is in the range of 180 and 260 mg/L

Key value for chemical safety assessment

Water solubility:

180 mg/L

at the temperature of:

20 °C

Additional information

Klawonn, 2010:

Water solubility of ammonium trivanadium octaoxide under O2 and CO2 exclusion, loading of approx. 2 g/L: 180 ± 3.2 mg/L after 72 h at 20 °C (pH 3.9).

Seagrave, Julien 2012:

Ammonium trivanadium octaoxide has a water solubility of 260 mg/L at 20 °C and pH 4.0.