Yttrium zirconium oxide

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:

2008-02-25 to 2009-11-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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)

Remarks:

certificate provided by Rheinlandpfalz

Type of method:

column elution method

Key result

Water solubility:

< 55 µg/L

Temp.:

20 °C

pH:

6.5

Details on results:

Limit of detection was calculated from the calibrated range to be 40.8 µg/L Zr, corresponding to 55 µg/L ZrO2. As none of the samples showed a signal at the voltage of the Zr-Alizarin-peak, concentration in the samples and therefore water solubility was considered to lie below LOD.
No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

Conclusions:

The water solubility of the test item was found to be < 55 µg/L at a temperature of 20 +/- 0.5 degrees C and a pH of 6.5.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 17 NOV 2005 (study plan audited by the quality assurance) to 07 DEC 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

and EU method A6 (water solubility) (in the report : EEC directive 92/69, A6)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Water solubility:

0.7 mg/L

Temp.:

20 °C

pH:

6.8 - 7.1

Details on results:

The measured results differ by less than 30%. Therefore, the study is considered to be valid.

Table 1: Results of the water solubility of YTTRIUM OXYDE

Experi-ment No.	Flow rate (ml/h)	Sample No.	Concentra- tion analysed (µg Yttrium/l)	Mean (µg Yttrium/l)	Water solubility calculated * (µg Test item/l)	Water solubility calculated (mg Test item/l)	Water solubility calculated (mg Test item/l)	pH
1	31	1.1 1.2	556 559	557.5	712.551	0.71 SD =±0.00 Srel =±0.68%	0.70 SD =±0.01 Srel =±0.81%	6.87
		2.1 2.2	549 552	550.5	703.604			6.95
		3.1 3.2	553 556	554.5	708.717			6.80
		4.1 4.2	550 549	549.5	702.326			7.03
		5.1 5.2	553 556	554.5	708.717			6.91
		6.1 6.2	548 547	547.5	699.770			6.97
2	16	7.1 7.2	549 550	549.5	702.326	0.70 SD =±0.01 Srel =±0.81%		7.07
		8.1 8.2	540 554	547.0	699.131			6.91
		9.1 9.2	551 543	547.0	699.131			6.85
		10.1 10.2	548 549	548.5	701.048			6.94
		11.1 11.2	538 537	537.5	686.989			6.89
		12.1 12.2	551 546	548.5	701.048			6.94

 

SD = Standard deviation

* calculated with a content of yttrium = 78.2400%

Conclusions:

The water solubility of yttrium oxide is 0.70 mg/L (+/- 0.01 mg/L) at 20°C.

Executive summary:

The determination of the water solubility of yttrium oxide was performed according to the EEC Directive 92/69, A.6 “Water Solubility” (1992) and the OECD guideline No. 105, “Water Solubility” (adopted July 27, 1995), using the column elution method.

During the pre-tests, the water solubility of the test item at room temperature was estimated to be < 10 mg/L by visual judgement. Therefore, the column elution method was used for the performance of the main test. During the main test, six samples have been analysed in the first run (0.52 mL/min) and six samples during the second run (0.26 mL/min), each with a sampling interval of one hour. Total elution time was 94 hours.

The water solubility of the test item is 0.70 mg/L (+/- 0.01 mg/L) at 20°C.

The pH of the solution was between 6.80 and 7.07.

Reference 3

Endpoint:

water solubility

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

The water solubility of yttrium zirconium oxide based on a weight of evidence approach using water solubility data for the individual substances zirconium dioxide (insoluble, < 55 µg/L, Paulus, 2010) and yttrium oxide (slightly soluble, 0.7 mg/L, Weissenfeld, 2006), can be expected to be extremely low too. Because no exact value can be determined, it can not be concluded whether the substance is to be considered as insoluble (< 0.1 mg/L) or slightly soluble in water (0.1-100 mg/L).

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Water solubility:

< 1 mg/L

Remarks on result:

other: The water solubility is determined to be low but it can not be concluded whether the substance is to be considered as insoluble (< 0.1 mg/L) or slightly soluble in water (0.1-100 mg/L)

Description of key information

No key information is available on the water solubility of yttrium zirconium oxide, however, based on a weight of evidence approach using water solubility data for the individual substances zirconium dioxide (insoluble, < 55 µg/L, Paulus, 2010) and yttrium oxide (slightly soluble, 0.7 mg/L, Weissenfeld, 2006), the solubility of yttrium zirconium oxide can be expected to be extremely low too. Because no exact value can be determined however, it cannot be concluded whether the substance is to be considered as insoluble (< 0.1 mg/L) or slightly soluble in water (0.1-100 mg/L).

Additional information

1. Information on zirconium dioxide (CAS# 1314-23-4)

The water solubility of zirconium dioxide was determined following the OECD 105 and EC A.6 test methods to be < 55 µg/L at 20°C (Paulus, 2010). Therefore, the substance is considered insoluble in water (< 0.1 mg/L).

2. Information on yttrium oxide (CAS# 1314-36-9)

The determination of the water solubility of yttrium oxide was performed according to the EEC Directive 92/69, A.6 “Water Solubility” (1992) and the OECD guideline No. 105, “Water Solubility” (adopted July 27, 1995), using the column elution method. The water solubility of yttrium oxide is 0.70 mg/L (+/- 0.01 mg/L) at 20°C. Therefore, the substance is considered slightly soluble in water (0.1-100 mg/L).

3. Conclusion on yttrium zirconium oxide (CAS# 64417-98-7)

It is expected that the substance has a similarly low water solubility as the read across substances zirconium dioxide and yttrium oxide. No exact value can be derived (and hence, no conclusion can be drawn on whether the substance should be considered as insoluble or slightly soluble in water).