Cesium potassium fluoroaluminate

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Study period:

From 30 Oct 2003 to 27 April 2004

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: See remark.

Remarks:

Although the study was performed according to the OECD 107 guideline and under CLP conditions, the Log Pow is not a valid descriptor for assessing the bioaccumulation potential of inorganic compounds. For this reason, the study is disregarded for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

no

GLP compliance:

yes

Type of method:

shake-flask method to: flask method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Test material form:

solid: particulate/powder

Details on test material:

Cesium potassium fluoroaluminate, purity 100%

Study design

Analytical method:

other: ICP-MS

Results and discussion

Partition coefficient

Type:

log Pow

Partition coefficient:

< -3.6

Temp.:

20 °C

pH:

5.7

Details on results:

n-Octanol solubility

Preliminary test:
Test substance was stirred with n-octanol for 7 days at 20.2 ± 0.7°C (nominal concentration was 40 g/L). The concentrations of Cesium potassium fluoroaluminate in the supernatant after three and four successive centrifugation steps (3500 g, 5 min., 20°C) were calculated from the Cs and were 2.7x10E-3 g/L and 1.6x10E-3 g/L, respectively.
Because a significant difference was observed between the concentrations analysed after the third and fourth centrifugation steps, it was concluded that not all undissolved test substance had been removed after three centrifugation steps and that the n-octanol solubility of the test substance was ≤ 1.6x10-3 g/L. lt was decided to centrifuge the n-octanol samples from the main study four times and to check the centrifugation step again.

Main study:
Test substance was stirred with n-octanol (in triplicate) at a nominal concentration of approximately 7x10-2 g/L. Duplicate samples were taken from each n-octanol mixture after 24, 48 or 72 hours of stirring. Undissolved test substance was removed by four successive centrifugation steps (3500 g, 5 min., 20°C). The n-octanol phases were analysed for Cs and concentrations of Cesium potassium fluoroaluminate were calculated. The temperature of the climate room was 20.4 ± 0.5°C during the performance of the test.

The 24-, 48- and 72- hour measurements are in agreement. Therefore, the n-octanol solubility of Cesium potassium fluoroaluminate was calculated as the mean value of all measurements.

The 72 hours stirred n-octanol samples were also centrifuged a fifth time. Because no significant difference was observed between the concentrations analysed after the fourth centrifugation step (< 1.47x10E-3 g/L) and fifth centrifugation step (< 1.47x10E-3 g/L), it was concluded that all undissolved test substance had been removed after four centrifugation steps.

Any other information on results incl. tables

Results of the main study n-octanol solubility of cesium potassium fluoroaluminate:

Stirring time (hours	Concentrations analysed (mg/kg)	Mean concentration (g/L)
24	< 1.77 / < 1.77	< 1.47x 10E-3
48	< 1.77 / < 1.77	< 1.47x 10E-3
72	< 1.77 / < 1.77	< 1.47x 10E-3
Mean		< 1.47x 10E-3

ln conclusion, the n-octanol solubility of Cesium potassium fluoro aluminate (Cesium 5.64% w/w) at 20.4 ± 0.5°C is reported to be < 1.47x10E-3 g/L.

 

Water solubility: 

The water solubility of Cesium potassium fluoro aluminate at 20.4 ± 0.5°C is 5.99 g/L (NOTOX project 394572). The pH was measured to be 5.7.

Applicant's summary and conclusion

Conclusions:

The log kow of cesium potassium fluoroaluminate is lower than -3.6 at 20°C and pH = 5.7.

Executive summary:

The determination of the partition coefficient (n-octanol/water) of cesium potassium fluoroaluminate was determined according to the OECD 107 guideline and under GLP conditions. Since cesium potassium fluoroaluminate is a salt, both the flask-shaking method and the HPLC-method were not applicable. Because also calculation from the structural formula was not possible, the estimation method was used as the only possible alternative to determine the partition coefficient (n-octanol/water) of cesium potassium fluoroaluminate.

 

The estimation method is recognised by the international guidelines (EEC, OECD) and estimates the partition coefficient from the quotient of the n-octanol solubility and the water solubility. The solubility of the test substance in n-octanol was determined in the present study. The solubility of the test substance in water was determined in NOTOX project 394572.

 

The n-octanol solubility of cesium potassium fluoroaluminate at 20.4 ± 0.5°C was determined to be < 1.47x10E-3 g/L. The water solubility of cesium potassium fluoroaluminate at 20.4 ± 0.5°C and pH 5.7 is 5.99 g/L. The partition coefficient (n-octanol/ water), Pow, calculated as a quotient of the n-octanol solubility and the water solubility of cesium potassium fluoroaluminate is < 2.46x10E-4 (log Pow < -3.6).