Praseodymium trichloride

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 October 2017 - 20 November 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

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:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

trichloropraseodymium; heptahydrate

Cas Number:

10025-90-8

Molecular formula:

PrCl3.7H2O

IUPAC Name:

trichloropraseodymium; heptahydrate

Test material form:

solid: particulate/powder

Details on test material:

- Name of the test material (as in the report): praseodymium trichloride heptahydrate
- Physical state: solid
- Appearance: green crystalline powder
- Further information on test material confidential.

Results and discussion

Water solubility

Water solubility 1

Water solubility:

445 g/L

Conc. based on:

element (dissolved fraction)

Remarks:

praseodymium

Loading of aqueous phase:

3 600 g/L

Incubation duration:

>= 24 - <= 72 h

Temp.:

25 °C

pH:

5.5

Remarks on result:

other: mean of 24, 48 and 72 h

Water solubility 2

Key result

Water solubility:

> 1 000 g/L

Conc. based on:

test mat. (dissolved fraction)

Remarks:

praseodymium trichloride heptahydrate (recalculated from measured Pr concentrations)

Loading of aqueous phase:

3 600 g/L

Incubation duration:

>= 24 - <= 72 h

Temp.:

25 °C

pH:

5.5

Remarks on result:

other: mean of 24, 48 and 72 h

Details on results:

From the preliminary test, the solubility of the test item was determined to be > 1000 g/L (see "Any other information on results incl. tables").
Therefore, it was decided to perform the main test according to the flask method (for results see "Any other information on results incl. tables").

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: 375 g Pr/L (limit of detection: 125 g Pr/L).

Any other information on results incl. tables

Results of the preliminary test with milliQ water at pH 6 or buffer solution at pH 4, 7 or 9 (identical results):

Amount of test item weighed (g)	0.1
Volume of water added (mL)	0.1
Solubility (yes/no)	yes

Results of the main test:

	Solubility expressed as praseodymium content in water (g/L)	Solubility of praseodymium trichloride heptahydrate in water (g/L)	Mean pH measured	Temperature (°C)
Test 1 (24h)	449	1190	5.5	25
Test 2 (48h)	448	1187	5.5	25
Test 3 (Mean of 2 determinations) (72h)	440	1166	5.5	25
Mean (24, 48, 72h)	445	>1000	5.5	25

Applicant's summary and conclusion

Conclusions:

The mean solubility in water at pH 5.5 and 25°C when expressed as praseodymium content in water is 445 g/L and when expressed as praseodymium trichloride heptahydrate is > 1000 g/L (flask method).