Praseodymium(III,IV) oxide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 October 2007 - 6 May 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

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

Water solubility:

1.27 mg/L

Temp.:

20 °C

pH:

6.59 - 6.76

Details on results:

The measured results differ by less than 30 %. Therefore, the study is considered to be valid.

Table 1: Water solubility (Column Elution Method)

Experiment No.	Flow rate (mL/h)	Sample No.	Concentra- tion analysed * (mg Pr/L)	Water solubility calculated (mg Test material/L)	Water solubility calculated (mg Test material/L)	Water solubility calculated (mg Test material/L)	pH
1	31	1 2 3 4 5	1.04* 1.04* 1.04* 1.03* 1.03*	1.36 1.36 1.36 1.35 1.35	1.35 SD = ± 0.007	1.27 SD = ± 0.10	6.66 6.70 6.59 6.76 6.63
2	16	6 7 8 9 10 11	0.92* 0.91* 0.89* 0.89* 1.01* 0.83*	1.20 1.19 1.16 1.16 1.32 1.08	1.19 SD = ± 0.08		6.69 6.71 6.70 6.75 6.68 6.72

SD = Standard deviation

* Values measured by ICP / MS

Conclusions:

Interpretation of results: slightly soluble (0.1-100 mg/L)
The water solubility of the test material at 20 °C was determined to be 1.27 mg/L (standard deviation ± 0.10 mg/L) using the column elution method.

Executive summary:

The determination of the water solubility of the test material was performed using the column elution method in accordance with the standardised guidelines OECD 105 and EU Method A.6.

During pre-tests, the water solubility of the test material at room temperature was estimated to be < 9.24 mg/L by visual judgment. Therefore, the column elution method was used for the performance of the main test.

During the main test six samples were analysed in the first run (0.52 mL/min) and six samples during the second run (0.26 mL/min), each with a sampling interval of one hour. Total elution time was 120 hours.

The water solubility was calculated including the content of the test material given in the certificate of analysis. The water solubility at 20 °C was determined to be 1.27 mg/L (standard deviation ± 0.10 mg/L) using the column elution method.

Description of key information

The water solubility at 20 °C was determined to be 1.27 mg/L.

Key value for chemical safety assessment

Water solubility:

1.27 mg/L

at the temperature of:

20 °C

Additional information

The key study was conducted in line with GLP and the standardised guidelines OECD 105 and EU Method A.6. It was assigned a reliability score of 1 in accordance with the criteria detailed by Klimisch (1997).

During pre-tests, the water solubility of the test material at room temperature was estimated to be < 9.24 mg/L by visual judgment. Therefore, the column elution method was used for the performance of the main test.

During the main test six samples were analysed in the first run (0.52 mL/min) and six samples during the second run (0.26 mL/min), each with a sampling interval of one hour. Total elution time was 120 hours.

The water solubility was calculated including the content of the test material given in the certificate of analysis. The water solubility at 20 °C was determined to be 1.27 mg/L (standard deviation ± 0.10 mg/L) using the column elution method.