Vanadium zirconium yellow baddeleyite

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-02-17 to 2012-06-25

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

`mass balance (%) after completion of the transformation test´ is missing

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:

(ENV/JM/MONO(2001)9): Guidance Document on Transformation / Dissolution of Metals and Metal Compounds in Aqueous Media

Deviations:

yes

Remarks:

please refer to the field "Rationale for reliability incl. deficiencies" above

Qualifier:

according to guideline

Guideline:

other: EEC guideline SANCO/3029/99 rev. 4 dated 11/07/00: Working document “Guidance for generating and reporting methods of analysis in support of residue data requirements for Annex II (part A, Section 4) and Annex III (part A, Section 5)

Deviations:

no

GLP compliance:

yes

Type of method:

flask method

Type of test:

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

Mean dissolved conc.:

3 µg/L

Element analysed:

V

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH 8, 20 °C

Remarks on result:

other: S.D.: +/- 0.3 µg V/L

Type of test:

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

Mean dissolved conc.:

< 0.5 µg/L

Element analysed:

Zr

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH 8, 20 °C

Remarks on result:

other:

Key result

Type of test:

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

Mean dissolved conc.:

3.1 µg/L

Element analysed:

V

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH 8, 21.0 °C

Remarks on result:

other: S.D.: +/- 0.2 µg V/L

Key result

Type of test:

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

Mean dissolved conc.:

< 0.5 µg/L

Element analysed:

Zr

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH 8, 21.0 °C

Remarks on result:

other:

Key result

Type of test:

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

Mean dissolved conc.:

2.8 µg/L

Element analysed:

V

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 8, 21.1 °C

Remarks on result:

other: S.D.: +/- 0.3 µg V/L

Key result

Type of test:

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

Mean dissolved conc.:

< 0.5 µg/L

Element analysed:

Zr

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 8, 21.1 °C

Remarks on result:

other:

Type of test:

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

Mean dissolved conc.:

86.7 µg/L

Element analysed:

V

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH6, 21°C

Remarks on result:

other: S.D.: +/- 1.0 µg V/L

Key result

Type of test:

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

Mean dissolved conc.:

77.7 µg/L

Element analysed:

V

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH6, 21°C

Remarks on result:

other: S.D.: +/- 1.3 µg V/L

Type of test:

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

Mean dissolved conc.:

< 0.5 µg/L

Element analysed:

Zr

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH6, 21°C

Remarks on result:

not determinable

Remarks:

< LOD

Key result

Type of test:

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

Mean dissolved conc.:

< 0.5 µg/L

Element analysed:

Zr

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH6, 21°C

Remarks on result:

not determinable

Remarks:

< LOD

Type of test:

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

Mean dissolved conc.:

118.5 µg/L

Element analysed:

V

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH8, 21°C

Remarks on result:

other: S.D.: +/- 3.8 µgV/L

Key result

Type of test:

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

Mean dissolved conc.:

90 µg/L

Element analysed:

V

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH8, 21°C

Remarks on result:

other: S.D.: +/- 3.1µg V/L

Type of test:

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

Mean dissolved conc.:

3.1 µg/L

Element analysed:

Zr

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH8, 21°C

Remarks on result:

other: S.D.: +/- 0.4 µgZr/L

Key result

Type of test:

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

Mean dissolved conc.:

< 1 µg/L

Element analysed:

Zr

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH8, 21°C

Remarks on result:

other: < LOQ

Details on results:

The analytical method was shown to be suitable for low content determination of zirconium and vanadium in aqueous samples due to the technique ICP-MS.
The analyzed range, from 0.1 to 200 µg/L, was found to be linear for zirconium and vanadium (correlation coefficient > 0.99).
The instrumental limit of detection (IDL) defined as the lowest calibration level, was 0.1 µg/L for zirconium and vanadium.
The limit of quantification (LOQ) of the method was 1 µg/L for zirconium and vanadium, defined as the lowest fortification level.
The limit of detection (LOD) of the method, defined as 50 % of the lowest fortification level, was 0.5 µg/L for zirconium and vanadium.
Concentrations lower than the LOD were classified as not detected (n.d.).
Concentrations higher than the LOD but lower than the LOQ were designated as <1 µg/L for zirconium and vanadium.
The precision and the accuracy of the analytical method are in accordance with SANCO/3029/99 rev. 4.
From the results of the accuracy test it can be concluded that there was not a matrix effect and contamination (e.g. by the filter procedure) did not occur during sample processing.

Summary results for the 7d-full test with a loading of 100 mg/L at pH 6 

Full test 7 days at 100 mg/L		V (µg/L)	Zr (µg/L)
Solution pH 6 T0h	Mean	n.d.	n.d.
	SD	-	-
	RSD (%)	-	-
Solution pH 6 T2h	Mean	66.8	n.d.
	SD	3.9	-
	RSD (%)	5.9	-
Solution pH 6 T6h	Mean	74.1	n.d.
	S.D.	3.7	-
	RSD (%)	5.0	-
Solution pH 6 T1d	Mean	86.7	n.d.
	SD	1.0	-
	RSD (%)	1.1	-
Solution pH 6 T4d	Mean	85.2	n.d.
	SD	1.9	-
	RSD (%)	2.3	-
Solution pH 6 T7d	Mean	77.7	n.d.
	SD	1.3	-
	RSD (%)	1.6	-

Abbreviations: SD: Standard Deviation; RSD (%): Relative Standard Deviation %

n.d.: lower than the method Limit of Detection (LOD) (0.5 µg/L for V and Zr, respectively).

Summary results for the 7d-full test with a loading of 100 mg/L at pH 8 

Full test 7 days at 100 mg/L		V (µg/L)	Zr (µg/L)
Solution pH 8 T0h	Mean	n.d.	n.d.
	SD	-	-
	RSD (%)	-	-
Solution pH 8 T2h	Mean	108.5	5.9
	SD	3.6	0.5
	RSD (%)	3.4	8.1
Solution pH 8 T6h	Mean	111.7	5.2
	SD	2.2	0.5
	RSD (%)	2.0	9.0
Solution pH 8 T1h	Mean	118.5	3.1
	SD	3.8	0.4
	RSD (%)	3.2	11.2
Solution pH 8 T4h	Mean	100.7	1.2
	SD	4.9	0.2
	RSD (%)	4.9	14.3
Solution pH 8 T7h	Mean	90.0	<1
	SD	3.1	-
	RSD (%)	3.5	-

n.d.: lower than the method Limit of Detection (LOD) (0.5 µg/L for V and Zr, respectively)

<1.: lower than the method Limit of Quantification (LOQ) (1 µg/L for Zr) but higher than the Limit of Detection (LOD) (0.5 µg/L for Zr).

 

Summary results for the 28d-full test with a loading of 1 mg/L

Full test 28 days at 1 mg/L		V (µg/L)	Zr (µg/L)
Solution pH 8 T0h	Mean	n.d.	n.d.
	SD	-	-
	RSD (%)
Solution pH 8 T2h	Mean	2.6	n.d.
	SD	0.2	-
	RSD (%)	7.9
Solution pH 8 T6h	Mean	2.8	n.d.
	SD	0.2	-
	RSD (%)	7.2
Solution pH 8 T1d	Mean	3.0	n.d.
	SD	0.3	-
	RSD (%)	9.1
Solution pH 8 T4d	Mean	3.0	n.d.
	SD	0.3	-
	RSD (%)	8.6
Solution pH 8 T7d	Mean	3.1	n.d.
	SD	0.2	-
	RSD (%)	7.6
Solution pH 8 T14d	Mean	2.9	n.d.
	SD	0.4	-
	RSD (%)	13.0
Solution pH 8 T21d	Mean	3.0	n.d.
	SD	0.3	-
	RSD (%)	10.9
Solution pH 8 T28d	Mean	2.8	n.d.
	SD	0.3	-
	RSD (%)	10.6

n.d.: lower than the method Limit of Detection (LOD) (0.5 µg/L for V and Zr, respectively).

Parameters of linear calibration for V analysis of solutions from the 28d-full test:

m (slope): 0.5578

q (intercept): 0.0117

R²(correlation): 0.9997

Parameters of linear calibration for Zr analysis of solutions from the 28d-full test:

m (slope): 0.0838

q (intercept): 0.0060

R²(correlation): 0.9997

Analytical method (Inductively-Coupled-Plasma Mass-Spectrometry ICP-MS)

Specificity

Zirconium and vanadium concentrations of blanks from each test medium were analyzed. Zirconium and vanadium concentrations in blanks of the respective media were below the method LOD.

 

Linearity and System Precision

The analysed range of Zr and V concentrations, from 0.1 µg/L to 200 µg/L,was found to be linear (correlation coefficient > 0.99 for metal). Since the fortification levels for the recovery test were 1 µg/Land 10 µg/L, the linear calibration performed for recovery quantification ranged from 0.1 µg/L to 50 µg/L.

Parameters of linear calibration for V analysis of solutions from the recovery test:

m (slope): 0.5644

q (intercept): 0.0092

R²(correlation): 0.9994

Parameters of linear calibration for Zr analysis of solutions from the recovery test:

m (slope): 0.0850

q (intercept): 0.0029

R²(correlation): 0.9993

 

Repeatability (Precision) and Accuracy (Recovery)

For precision, the SANCO/3029/99 rev. 4 guideline requires an RSD to be lower than 20 % for each fortification level.

For accuracy, the SANCO/3029/99 rev. 4 guideline requires mean recovery values for each fortification level in the range from 70 to 110 %, ideally with the mean in the range 80 to 100 %.

Recovery (V)

Test Medium	Spike add	Mean Found	RSD (%)	Recovery Mean
pH 6	1 µg/L	1.0 µg/L	0.8	97.0 %
	10 µg/L	9.4 µg/L	1.5	94.5%
pH 8	1 µg/L	1.0 µg/L	2.3	95.5 %
	10 µg/L	10.0 µg/L	1.6	99.6 %

Recovery (Zr)

Test Medium	Spike add	Mean Found	RSD (%)	Recovery  Mean
pH 6	1 µg/L	0.7 µg/L	5.6	74.9 %
	10 µg/L	8.1 µg/L	3.4	81.2 %
pH 8	1 µg/L	0.7 µg/L	2.2	71.7 %
	10 µg/L	8.5 µg/L	1.7	84.8 %

Repeatability and Recovery test: Test medium at pH 6 

Elution medium pH 6	V (µg/L) (1)	V Recovery (%)	Zr (µg/L) (1)	Zr Recovery (%)
Buffer blank	n.d.	-	n.d.	-
Spike L1	0.97	96.94	0.71	70.79
Spike L2	0.98	97.77	0.79	79.24
Spike L3	0.96	96.30	0.75	74.57
Mean value:	1.0	97.0	0.7	74.9
Standard deviation (SD):	0.01	0.74	0.04	4.23
Relative Standard deviation (RSD (%)):	0.8	0.8	5.6	5.6
Elution medium pH 6	V (µg/L) (1)	V Recovery (%)	Zr (µg/L) (1)	Zr Recovery (%)
Buffer blank	n.d.	-	n.d.	-
Spike H1	9.50	94.97	8.38	83.81
Spike H2	9.56	95.62	8.13	81.32
Spike H3	9.29	92.88	7.83	78.34
Mean value:	9.4	94.5	8.1	81.2
Standard deviation (SD):	0.14	1.43	0.27	2.74
Relative Standard deviation (RSD (%)):	1.5	1.5	3.4	3.4

(1) Mean of two determinations.

n.d.: lower than the method Limit of Detection (LOD) (0.5 µg/L for V and Zr, respectively).

Repeatability and Recovery test: Test medium at pH 8 

Elution medium pH 8	V (µg/L) (1)	V Recovery (%)	Zr (µg/L) (1)	Zr Recovery (%)
Buffer blank	n.d.	-	n.d.	-
Spike L1	0.93	93.49	0.71	70.54
Spike L2	0.98	97.81	0.73	73.41
Spike L3	0.95	95.31	0.71	71.00
Mean value:	1.0	95.5	0.7	71.7
Standard deviation (SD):	0.02	2.17	0.02	1.54
Relative Standard deviation (RSD (%)):	2.3	2.3	2.2	2.2
Elution medium pH 8	V (µg/L) (1)	V Recovery (%)	Zr (µg/L) (1)	Zr Recovery (%)
Buffer blank	n.d.	-	n.d.	-
Spike H1	9.78	97.84	8.31	83.15
Spike H2	10.06	100.58	8.55	85.46
Spike H3	10.05	100.46	8.57	85.74
Mean value:	10.0	99.6	8.5	84.8
Standard deviation (SD):	0.16	1.55	0.14	1.42
Relative Standard deviation (RSD (%)):	1.6	1.6	1.7	1.7

(1) Mean of two determinations.

n.d.: lower than the method Limit of Detection (LOD) (0.5 µg/L for V and Zr, respectively).

Repeatability and Recovery test: Certified Reference Material analysis

	Ratio V/Ge	V (µg/L)	Ratio Zr/In	Zr (µg/L)
Certified Reference Material A	7.2860	12.89	-	-
Certified Reference Material B	7.3363	12.98	-	-
Certified Reference Material C	7.4960	13.27	-	-
Mean value(µg/L):	13.05		-
Standard deviation (SD):	0.19		-
Relative Standard deviation (RSD (%)):	1.5		-

Note: The Certified Reference Material does not report a certified value for zirconium.

Conclusions:

The transformation/dissolution of vanadium zirconium yellow baddeleyite was measured according to the method OECD test series No. 29 (Guidance document on transformation/dissolution of metals and metal compounds in aqueous media). The transformation/dissolution ofthe pigment resulted in the following dissolved concentrations:

Full test 7 days at 100 mg/L and pH 6: 77.7 ± 1.3 µg V/L and < 0.5 µg Zr/L
Full test 7 days at 100 mg/L and pH 8: 90.0 ± 3.1 µg V/L and < 1 µg Zr/L

Full test 7 days at 1 mg/L and pH 8: 3.1 ± 0.2 µg V/L and < 0.5 µg Zr/L
Full test 28 days at 1 mg/L and pH 8: 2.8 ± 0.3 µg V/L and < 0.5 µg Zr/L

The dissolved V and Zr concentrations were below 4 µg/L at a loading of 1 mg/L after 7 and 28 days, respectively, referring to a solubility of < 0.4 wt%.
At a loading of 100 mg/L the dissolved V and Zr concentrations were at 90 µg/L , referring to a solubility of ~ 0.09 %.
Thus, the extent to which the pigment can produce soluble available ionic and other metal-bearing species in aqueous media is limited.

Description of key information

The solubility of vanadium zirconium yellow baddeleyite is < 0.4 wt% at a 1mg/L loading and even lower ~0.09wt% at a 100 mg/L loading. A GLP-conform transformation/dissolution test with a loading of 100 mg/L at pH6 and ph8 over 7 days, revealed higher dissolution at pH 8. Dissolved V and Zr concentrations at a loading of 100mg/L were 90. µg/L and below LOQ (1.0 µg/L) at pH8 after 7 days, respectively (Pardo Martinez, 2013). Transformation/dissolution at a loading of 1 mg/L at pH 8 after 7 and 28 days resulted in dissolved zirconium concentrations below LOD. The dissolved vanadium concentrations at pH8 were of 3.1 µg/L and 2.8 µg/L after 7 and 28 days, respectively (Pardo Martinez, 2013).

The particle size of the tested sample (BET surface area 1 m2/g) is representative for the particle size on the market. Thus, the extent to which " vanadium zirconium yellow baddeleyite" can produce soluble available ionic and other metal-bearing species in aqueous media is limited.