Tall oil, maleated

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Initiation: September 24, 2013 Completion May 20, 2014

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:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

4.969

Temp.:

25 °C

pH:

2

Details on results:

Tall oil, maleated was composed of 15 or more peaks, ranging in retention time from approximately 2 to 25 minutes. The largest single peak (by peak area) eluted at approximately 7.9 minutes with seven other peaks large enough (> 5% of the total peak area ) to be included in the weighted average log Pow calculation. The retention time of the peak at 16.5 minutes corresponds to the retention time of linoleic acid, while the peak at 24.575 minutes corresponds to oleic acid. Maleic acid, if it were present, would elute at about 3.3 minutes under these conditions.

Conclusions:

The test item displayed a weighted average log Pow of 4.969.

Executive summary:

The determination of the partition coefficient on test item tall oil, maleated was conducted according to OECD Guideline for the Testing of Chemicals. Test No. 117: Partition Coefficient (n-octanol/water). The determination was done using High Performance Liquid Chromatography (HPLC) Method employing a reverse phase column and mobile phase comprised of phosphate buffer (pH 2) and methanol, in order to retain the test item in its neutral form. Reference standards and the test item were detected using a UV detector monitoring the general organic absorbance at 210 nm. The system was calibrated using pure reference standards having well documented log Pow values.

The test item was dissolved in methanol at a concentration of about 4.24 mg/mL. One mL of the methanolic stock was dissolved in 10 ml mobile phase, giving a final concentration in the 0.42 mg/mL range. This process was repeated to prepare a second sample of concentration 0.45 mg/mL. Each was analyzed independently by HPLC using 100 μL injections.

Tall oil, maleated was composed of 15 or more peaks, ranging in retention time from approximately 2 to 25 minutes. The largest single peak (by peak area) eluted at approximately 7.9 minutes with seven other peaks large enough (> 5% of the total peak area ) to be included in the weighted average log Pow calculation. The retention time of the peak at 16.5 minutes corresponds to the retention time of linoleic acid, while the peak at 24.575 minutes corresponds to oleic acid. Maleic acid, if it were present, would elute at about 3.3 minutes under these conditions.

The test item displayed a weighted average log Pow of 4.969.

The error in the measurements was estimated using the relative percent difference (RPD) of the two independent preparations analysed in these experiments. The difference between the two preparations was 0.009 log units, corresponding to 0.18% relative difference.

Description of key information

The test item displayed a weighted average log Pow of 4.969.

Key value for chemical safety assessment

Log Kow (Log Pow):

4.969

at the temperature of:

25 °C