Reaction mass of 2,6-Bis[(dimethylamino)methyl]-4-(1-{3-[(dimethylamino)methyl]-4-hydroxyphenyl}-1-methylethyl)phenol and 4-(1-{3,5-Bis[(dimethylamino)methyl]-4-hydroxyphenyl}-1-methylethyl)-2,6-bis[(dimethylamino)methyl]phenol

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

3.2

Temp.:

25 °C

pH:

7.2

Remarks on result:

other: peak 1

Type:

log Pow

Partition coefficient:

4

Temp.:

25 °C

pH:

7.2

Remarks on result:

other: peak 2

Details on results:

Since the test item is ionisable at any pH value (a non-ionic form does not exist), the measurement was performed at pH 7 (aqueous part of the mobile phase), which is relevant for the natural environment. The prescribed analytical HPLC method applied for the log Pow determination according to OECD TG 117 merely allows a relatively poor chromatographic resolution of the constituents of the item. Constituent 3 (Mannich Base 2 substituted) has presumably been co-eluted with Mannich Base 4 substituted.
For this reason, log Pow values for the two detectable constituents were calculated for their respective peak maxima. For both signals individual log Pow values were determined.
The partition coefficient range of the test item at 25 °C at pH 7 is determined to be: 3.2 to 4.0.

In order to ensure a stable performance of the HPLC column, the column temperature was set to 40 °C. The reference Pow-values in the OECD guideline presumably refer to 25 °C. Even though the column temperature was 40 °C, this temperature has no influence on the result of the determination. Therefore the Pow -valu of the test item determined within this study also refers to 25 °C.

Conclusions:

The partition coefficient range of HPP 12879-1 at 25 °C at pH 7 is determined to be: 3.2 to 4.0.

Executive summary:

For the test item HPP 12879-1, the partition coefficient was determined by the HPLC-method according to OECD TG 117.

According to the results of the material balance the test item is described as a mixture of three constituents representing a content of > 99 %. Since the test item is ionisable at any pH value (a non-ionic form does not exist), the measurement was performed at pH 7 (aqueous part of the mobile phase), which is relevant for the natural environment.

The prescribed analytical HPLC method applied for the log Pow determination according to OECD TG 117 merely allows a relatively poor chromatographic resolution of the constituents of the item. Constituent 3 (Mannich Base 2 substituted) has presumably been co-eluted with Mannich Base 4 substituted.

For this reason, log Pow values for the two detectable constituents were calculated for their respective peak maxima. The partition coefficient of HPP 12879 -1 at 25 °C at pH 7 is determined to be: log Pow (range): 3.2 to 4.0

Description of key information

The partition coefficient range of HPP 12879-1 at 25 °C at pH 7 is determined to be: 3.2 to 4.0 by the HPLC-method according to OECD TG 117

Key value for chemical safety assessment

Log Kow (Log Pow):

4

at the temperature of:

25 °C

Additional information

According to the results of the material balance the test item is described as a mixture of three constituents representing a content of > 99 %. Since the test item is ionisable at any pH value (a non-ionic form does not exist), the measurement was performed at pH 7 (aqueous part of the mobile phase), which is relevant for the natural environment.

The prescribed analytical HPLC method applied for the log Pow determination according to OECD TG 117 merely allows a relatively poor chromatographic resolution of the constituents of the item. Constituent 3 (Mannich Base 2 substituted) has presumably been co-eluted with Mannich Base 4 substituted.

For this reason, log Pow values for the two detectable constituents were calculated for their respective peak maxima.