Registration Dossier

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 guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.6 (Water Solubility)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
column elution method

Test material

Reference
Name:
Unnamed
Type:
Constituent
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.