Dimethyl propylphosphonate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study without restrictions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Version / remarks:

(adopted, May 2008)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

0.5

Temp.:

25 °C

pH:

7

Details on results:

The partition coefficient (Pow) of dimethyl propylphosphonate was determined according to the HPLC method at 40 °C. In order to comply with the guideline OECD 117 and considering environmental relevance, buffered water at approx. pH 7 was chosen. The reference Pow values in the OECD-guideline presumably refer to 25 °C. Even though the column temperature was 40 °C, this temperature is without influence on the result of the determination. The calibration was done referring to Pow values of reference substances determined at 25 °C.
The chromatogram of the test item dimethyl propylphosphonate showed 1 signal eluting at 2.3 minutes. No calibration substance with a Pow value below the value for the signal of the test item was available. For this reason the results for this signal was extrapolated.
Although the determined value does not exactly meet the range of application of the test guideline (0.5 - 2.8), we consider the value as valid (measurement uncertainty +/- 0,5 log units).
Remark:
Contrary to the calibration substances, the test item dimethyl propylphosphonate could only be detected with MSD instead of DAD. Because of the small difference in the retention times between the two detectors, no significant influence on the outcome of the study was assumed.

No pKa value of the test item dimethyl propylphosphonate could be calculated because no ionizable centers are available (calculated with the software ACD/pKa v 7.0 at the structure of the test item). Therefore the undissociated form of dimethyl propylphosphonate exist between pH values of 0 – 14. The test can be carried out in, buffered water at approx. pH 7.

Conclusions:

According to the OECD 117 the partition coefficient (log Pow) of dimethyl propylphosphonate was determined as 0.5 at 25 °C and pH 7.

Executive summary:

The partition coefficient (Pow) of dimethyl propylphosphonate was determined according to the HPLC method at 40 °C. In order to comply with the guideline OECD 117 and considering environmental relevance, buffered water at approx. pH 7 was chosen. The reference Pow-values in the OECD guideline presumably refer to 25 °C. Even though the column temperature was 40 °C, this temperature is without influence on the result of the determination. The calibration was done referring to Pow values of reference substances determined at 25 °C.

The chromatogram showed one signal eluting at 2.3 minutes. No calibration substance with a Pow value below the value for the signal of dimethyl propylphosphonate was available. For this reason the results for this signal was extrapolated. Although the determined value does not exactly meet the range of application of the test guideline (0.5 - 2.8), we consider the value as valid (measurement uncertainty +/- 0.5 log units). The result of log Pow for dimethyl propylphosphonate was 0.5.

Description of key information

According to the OECD 117 the partition coefficient (log Pow) of dimethyl propylphosphonate was determined as 0.5 at 25 °C and pH 7.

Key value for chemical safety assessment

Log Kow (Log Pow):

0.5

at the temperature of:

25 °C

Additional information

The partition coefficient (Pow) of dimethyl propylphosphonate was determined according to the HPLC method at 40 °C. In order to comply with the guideline OECD 117 and considering environmental relevance, buffered water at approx. pH 7 was chosen. The reference Pow-values in the OECD guideline presumably refer to 25 °C. Even though the column temperature was 40 °C, this temperature is without influence on the result of the determination. The calibration was done referring to Pow values of reference substances determined at 25 °C.

The chromatogram showed one signal eluting at 2.3 minutes. No calibration substance with a Pow value below the value for the signal of the test item was available. For this reason the results for this signal was extrapolated. Although the determined value does not exactly meet the range of application of the test guideline (0.5 - 2.8), we consider the value as valid (measurement uncertainty +/- 0.5 log units). The result of log Pow was 0.5.