Registration Dossier

Administrative data

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
13 July 2016 - 03 November 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: ZrB2-3.2/14
- Expiration date of the lot/batch: 04 March 2017
- Purity: 99%
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Controlled room temperature (15-25 ºC, below 70% relative humidity), protected from light and humidity
OTHER SPECIFICS:
Description: Grey powder (the colour was determined by visual inspection upon arrival at test facility)
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 solubilityopen allclose all
Key result
Water solubility:
< 0.003 mg/L
Conc. based on:
element (dissolved fraction)
Remarks:
zirconium
Temp.:
20 °C
pH:
6.4
Remarks on result:
other: LOQ = 0.003 mg Zr/L
Key result
Water solubility:
0.27 mg/L
Conc. based on:
element (dissolved fraction)
Remarks:
boron
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 10 ng/mL for B (0.1 mg/L in the sample) and 0.3 ng/mL for Zr (0.003 mg/L in the sample).
- Limit of detection: The LOD was found to be 2.5 ng/mL for B and 0.075 ng/mL for Zr.

Any other information on results incl. tables

Results of the preliminary test with milliQ water as the solvent 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 > 96 h of agitation)

Since the solubility was < 0.01 g/L, the main test was performed according to the column elution method.

Results of the main test, expressed as boron:

 

Solubility expressed as

boron content in water (mg/L)

Mean pH measured Temperature (°C)

 Test 1

(flow 25mL/hour)

 0.26  6.4  20°C

 Test 2

(flow 25 mL/hour)

 0.27  6.4  20°C

 Test 3

(flow 12.5 mL/hour)

 0.27  6.4  20°C
 Mean  0.27  6.4  20°C

The mean solubility in water was 0.27 mg B/L at pH 6.4 and at 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 25mL/hour)

 <LOQ  6.4  20°C

 Test 2

(flow 25mL/hour)

 <LOQ  6.4  20°C

 Test 3

(flow 12.5mL/hour)

 <LOQ  6.4  20°C
 Mean  <LOQ (0.003 mg/L)  6.4  20°C

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

Applicant's summary and conclusion

Conclusions:
The water solubility (expressed as boron and zirconium content in water) of the test substance was determined to be 0.27 mg/L (for boron) and < LOQ (0.003 mg/L) (for zirconium) at pH 6.4 and 20°C.