Ethyltriphenylphosphonium iodide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2003-12-11 to 2004-01-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

Adopted July 27,1995

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

December 1992

GLP compliance:

yes

Type of method:

flask method

Key result

Water solubility:

7.84 g/L

Conc. based on:

act. ingr. (total fraction)

Temp.:

20.1 °C

pH:

7.8

Details on results:

Preliminary test:
Test substance was stirred overnight with double distilled water at 20.3 ±0.5°C (nominal concentration was 19.0 g/L). The concentration of Ethyltriphenylphosphonium iodide in the aqueous phase after two and three successive times of centrifugation (3500 g, 5 min, 20°C) was 8.14 g/L and 7.84 g/L, respectively. From this it could be safely concluded that the water solubility of Ethyltriphenylphosphonium iodide is >/= 10 mg/L. Therefore, the flask method was chosen for the determination of the water solubility of Ethyltriphenylphosphonium iodide. The pH of the aqueous phase after two and three centrifugation steps was 7.4 and 6.9, respectively. Because no significant difference was observed between the concentrations analysed after the second and third centrifugation steps, it was concluded that all undissolved test substance had been removed after two centrifugation steps. Therefore, it was decided to centrifuge the water samples from the main study twice.

Main study (flask method):
Test substance was stirred with double distilled water (in triplicate) at a nominal concentration of approximately 42 g/L. Duplicate samples were taken from each water mixture after 24, 48 or 72 hours of stirring. Undissolved test substance was removed by two successive centrifugation steps (3500 g, 5 min, 20°C). The aqueous phases were analysed for Ethyltriphenylphosphonium iodide. The temperature of the climate room was 20.1 ±0.9°C during the performance of the test.
One of the 72 hours stirred water sample was also centrifuged a third time. Because no significant difference was observed between the concentrations analysed after the second centrifugation step (7.83 g/L) and third centrifugation step (7.89 g/L), it was concluded that all undissolved test substance had been removed after two centrifugation steps.
The duplicate samples of the 24-hour measurement deviated by 20% from each other. Therefore, the water solubility of Ethyltriphenylphosphonium iodide was calculated as the mean value of the 48- and 72- hour measurements.

The water solubility of Ethyltriphenylphosphonium iodide at 20.1 ±0.9°C was determined to be 7.84 g/L using the flask method. The pH of the aqueous sample after 72 hours stirring was 7.8.

Conclusions:

The water solubility of Ethyltriphenylphosphonium iodide was determined to be 7.84 g/L at 20.1 ± 0.9°C by using the flask method. The pH of the aqueous sample after 72 hours stirring was 7.8.

Description of key information

7.84 g/L at 20.1 ± 0.9°C

The pH of the aqueous sample after 72 hours stirring was 7.8.

Key value for chemical safety assessment

Water solubility:

7.84 g/L

at the temperature of:

20.1 °C

Additional information

GLP study according to OECD Guideline 105 (adopted 27 July 1995) and EU method A.6 (December, 1992) using the flask method