Registration Dossier

Physical & Chemical properties

Water solubility

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 5 September 2012 to 13 March 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose for cross-reference:
reference to same study
Qualifier:
according to guideline
Guideline:
EU Method A.6 (Water Solubility)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of method:
other: preliminary estimate of solubility by visual judgement with an investigation of the influence of pH variations
Key result
Water solubility:
>= 1 312 - <= 2 304 g/L
Temp.:
23 °C
pH:
0.39 - 0.58
Remarks on result:
other: The test item was completely dissolved at 1312 g/L while precipitation was observed at 2304 g/L.
Key result
Water solubility:
< 965 g/L
Temp.:
21.8 °C
pH:
5.04
Remarks on result:
other: A significant impact of pH = ca. 5 was observed on solubility, the test item precipitating. No maximum solubility could be determined. That is the reason why yttrium trinitrate hydrosolubility was determined at a concentration lower than 965 g/L.
Key result
Water solubility:
< 565 g/L
Temp.:
23.8 °C
pH:
6.18
Remarks on result:
other: A significant impact of pH = ca. 6 was observed on solubility, the test item precipitating. No maximum solubility could be determined. That is the reason why yttrium trinitrate hydrosolubility was determined at a concentration lower than 565 g/L.
Key result
Water solubility:
< 506 g/L
Temp.:
21.6 °C
pH:
9.29
Remarks on result:
other: A significant impact of pH = ca. 9 was observed on solubility, the test item precipitating. No maximum solubility could be determined. That is the reason why yttrium trinitrate hydrosolubility was determined at a concentration lower than 506 g/L.
Details on results:
After a preliminary assay, the maximum solubility in demineralised water of yttrium trinitrate was determined to be between 1312 and 2304 g/L at ca. 23 to 24°C. The pH of the solutions was between 0.39 and 0.58.

The influence of pH increase was then investigated by adding sodium hydroxide at 2.0 mol/L to a newly prepared solution of yttrium trinitrate at ca. 1320 g/L. After adjustment to pH = 5.04, the test item was not dissolved; a whitish precipitate was observed. Yttrium trinitrate hydrosolubility was determined at a concentration lower than 965 g/L.

After subsequent addition of sodium hydroxide at 2.0 mol/L to this last solution, a pH = 6.18 was obtained. The test item was not dissolved, a whitish precipitate was observed. It became difficult to homogenise the solution. Yttrium trinitrate hydrosolubility was determined at a concentration lower than 565 g/L.

Finally, the influence of pH increase was investigated a last time by adding sodium hydroxide at 5.0 mol/L to a newly prepared solution of yttrium trinitrate at ca. 1296 g/L. A pH = 9.29 was obtained. The test item was not dissolved; a whitish precipitate was observed. It became difficult to homogenise the solution. Yttrium trinitrate hydrosolubility was determined at a concentration lower than 506 g/L.

Results:

Assay No.  Test item weight (g) Demineralised water added (mL) Volume in graduated cylinder (mL) Concentration (g/L) Substance dissolved pH value 
 1  5.0847  4.0  6.4  794.5  Yes  1.70 at 22.8 °C
 2  5.0492  3.0  5.4  935.0  Yes  1.21 at 23.1 °C
 3  5.0263  2.0  4.3  1169  Yes  0.95 at 23.5 °C
 4  5.0698  1.0  2.2 2304   No  0.39 at 23.0 °C
 5  4.9867  1.5  3.8  1312  Yes  0.58 at 24.1°

Based on the above results, the maximum solubility observed was visually determined as ranging between 1312 and 2304 g/L at ca. 23 to 24°C. The pH of the solution was comprised between 0.39 and 0.58.

Conclusions:
The maximum water solubility of yttrium trinitrate was determined in a pre-test by visual observation to be in the range of 1312 to 2304 g/L (very soluble) at ca. 23 to 24°C. The pH was between 0.39 and 0.58. Increasing the pH of the solution significantly decreased the solubility of the substance in water.

Description of key information

In a GLP study according to the preliminary test as specified in test method EC A.6, yttrium trinitrate was determined to be very soluble in water with a maximum solubility in the range of 1.312 to 2.304 kg/L, under ambient conditions and a pH of 0.39 to 0.58 (Demangel B, 2013; Klimisch 1). The solubility was significantly decreased when the pH was adjusted to environmental values, due to the precipitation of the test item. 

Key value for chemical safety assessment

Water solubility:
100 g/L
at the temperature of:
20 °C

Additional information

Although the maximum solubility in water was determined to be in the range of 1312 g/L to 2304 g/L, a bounded value of 100 g/L is used as the key value for chemical safety assessment, being the maximum value for water solubility as defined in the EUSES program. When increasing the pH to approximately 5, 7 or 9, a whitish precipitate was observed at all these pH values, indicating a significantly lower water solubility at higher pH values.