Registration Dossier

Administrative data

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
02 November 2017 - 12 April 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report date:
2018

Materials and methods

Test guidelineopen allclose all
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)
Type of method:
column elution method

Test material

Constituent 1
Chemical structure
Reference substance name:
ytterbia stabilised yttrium disilicate
Molecular formula:
Yb2-xYxSi2O7
IUPAC Name:
ytterbia stabilised yttrium disilicate
Test material form:
solid: particulate/powder
Details on test material:
Name: ytterbium doped yttrium disilicate
Physical state: solid
Appearance: white powder
Further information on test material confidential.

Results and discussion

Water solubilityopen allclose all
Key result
Water solubility:
0.9 mg/L
Conc. based on:
element (dissolved fraction)
Remarks:
yttrium
Temp.:
20 °C
pH:
6
Remarks on result:
other: Expressed as yttrium content in water; mean of flow rates 12.5 mL/h and 6.25 mL/h.
Key result
Water solubility:
0.05 mg/L
Conc. based on:
element (dissolved fraction)
Remarks:
ytterbium
Temp.:
20 °C
pH:
6
Remarks on result:
other: Expressed as ytterbium content in water; mean of flow rates 12.5 mL/h and 6.25 mL/h.
Details on results:
Yttrium:
Results were validated by:
- Linearity validation: The analysis showed a good linearity of the method (r > 0.99).
- Accuracy validation: Results in dilution mixture showed a good accuracy which indicates acceptable data (recoveries ranged between 70 and 110%).
- Repeatability validation: The results indicated a good precision of the data (RSD < 20%).
- Specificity: The intensity (CPS) of blank samples measured was negligible.
- Limit of quantification: 0.1 mg Y/L
- Limit of detection: 0.02 mg Y/L

Ytterbium:
Results were validated by:
- Linearity validation: The analysis showed a good linearity of the method (r > 0.99).
- Accuracy validation: Results in dilution mixture showed a good accuracy which indicates acceptable data (recoveries ranged between 70 and 110%).
- Repeatability validation: The results indicated a good precision of the data (RSD < 20%).
- Specificity: The intensity (CPS) of blank samples measured was negligible.
- Limit of quantification: 0.03 mg Yb/L
- Limit of detection: 0.01 mg Yb/L

Any other information on results incl. tables

Results of the preliminary test with milliQ water and at pH 6 were:

Amount of test item weighed (g) 0.1 0.1 0.1 0.1 0.1 0.1  0.01
Volume of water added (mL) 0.1 0.5 1 2 10 100 1000
Solubility (yes/no) No No  No  No  No No No (after > 96 h of agitation of the test solution)

Results of the main test

 

Solubility expressed as

Yttrium content in water (mg/L)

Solubility expressed as Ytterbium content in water (mg/L)

Mean pH measured

Temperature (°C)

Test 0

(flow 25 mL/h)

Mean 0.2 mg/L - not stable

Mean 0.01 mg/L - not stable

 6

 20

Test 1

(flow 12.5 mL/h)

0.9 0.03  6  20

Test 2

(flow 12.5 mL/h)

 0.8  0.04  6  20

Mean (Test 1 and

Test 2)

 0.9

 0.04

 6

 20

Test 3

(flow 6.25 mL/h)

 0.8  0.05  6  20

Mean (12.5 mL/h and 6.25 mL/h)

 0.9  0.05  6  20

 

Applicant's summary and conclusion

Conclusions:
During the water solubility test with ytterbium doped yttrium disilicate, performed according to the column elution method, the water solubility of yttrium from the test substance was determined to be 0.9 mg Y/L, and that of ytterbium was determined to be 0.05 mg Yb/L. The test was performed at 20°C and the average pH measured during the test was 6.