Strontium zirconium trioxide

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 March 2016 – 18 March 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Test material

Test material information

Constituent 1

Reference substance name:

Strontium zirconium trioxide

EC Number:

234-847-4

EC Name:

Strontium zirconium trioxide

Cas Number:

12036-39-4

Molecular formula:

SrZrO3

IUPAC Name:

strontium zirconium trioxide

Test material form:

solid: particulate/powder

Details on test material:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: SZ-380-STM-16
- Expiration date of the lot/batch: 04 March 2017
- Purity: > 98%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage conditions of test material: room temperature (15-25 ºC, below 70% relative humidity), protected from light and humidity

OTHER SPECIFICS:
- Safety precautions: Routine safety precautions (lab coat, gloves, safety glasses, face mask) for unknown materials were applied to assure personal health and safety.

Results and discussion

Water solubility

Key result

Water solubility:

2.2 mg/L

Conc. based on:

other: extrapolation based on measured Sr solubility

Temp.:

20 °C

pH:

6.4

Details on results:

Results were validated by:
- Linearity validation: The analysis showed a good linearity of the method (r > 0.99)
- Accuracy validation: Results of accuracy in dilution mixture showed a good accuracy which indicates acceptable data (recoveries ranged between 75% and 125%).
- Repeatability validation: The results indicated a good precision of the data.
- Specificity: The intensity (CPS) of blank samples measured was negligible or similar to solvent intensity.
- Limit of quantification: The LOQ was set at 1.5 ng/mL for Sr (0.075 mg/L in the sample) and 0.03 ng/mL for Zr (0.0003 mg/L in the sample).
- Limit of detection: The LOD was found to be 0.1 ng/mL for Sr and 0.01 ng/mL for Zr.

Any other information on results incl. tables

Results of the preliminary test with milliQ at pH 6.4 are as follows:

Amount of test item weighed (g)	0.01
Volume of water added (mL)	1000
Solubility (yes/no)	no (after 72 h of agitation)

Based on the preliminary test, the solubility of the test item is < 0.01 g/L. Therefore the main test was performed using the column elution method.

Results of the main test, expressed as strontium

	Solubility expressed as strontium content in water (mg/L)	SrZrO3 solubility based on extrapolation (mg/L)	Mean pH measured	Temperature (°C)
Test 1 (flow 25 mL/hour)	0.7	1.8	6.4	20°C
Test 2 (flow 12.5 mL/hour)	1.0	2.6	6.4	20°C
Test 3 (flow 12.5 mL/hour)	0.9	2.3	6.4	20°C
Mean	0.9	2.2	6.4	20°C

Results of the main test, expressed as zirconium

	Solubility expressed as zirconium content in water (mg/L)	Mean pH measured	Temperature (°C)
Test 1 (flow 25 mL/hour)	<LOQ	6.4	20°C
Test 2 (flow 25 mL/hour)	<LOQ	6.4	20°C
Test 3 (flow 12.5 mL/hour)	<LOQ	6.4	20°C
Mean	<LOQ	6.4	20°C

The mean solubility in water is below the LOQ at pH 6.4 and at 20°C (expressed as zirconium content in water).

LOQ = 0.0003 mg/L

Applicant's summary and conclusion

Conclusions:

The water solubility of the test substance was determined according to the column elution method. Both strontium and zirconium concentrations were measured. Zirconium concentrations were below the LOQ (< 0.0003 mg/L) in all samples analysed. Strontium concentrations were measurable and were between 0.7 and 1.0 mg/L in all samples analysed, the average measured concentration being 0.9 mg/L. Based on this average value, the water solubility of strontium zirconium trioxide was extrapolated to be 2.2 mg/L (at pH 6.4 and 20°C). Note that this value is an overestimation, as both elements dissolve to a different extent from the substance when in water.