Reaction mass of N-(hydroxymethyl)hexadecan-1-amide and N-(hydroxymethyl)stearamide

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14.11.-20.12.18

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)

Version / remarks:

13.04.2004

Deviations:

no

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:

> 6.5

Temp.:

25 °C

Remarks on result:

other: HPLC screening, pH is not determined

Executive summary:

The study was performed using a HPLC with a C18 column. Eight reference items with different retention times and thiourea for the determination of the dead time were used to produce a calibration curve, since retention time on hydrophobic columns and P_OWare correlated. The reference items were chosen based on the results of the pre-test.

One vial was filled with the reference item mix and one vial with the test item solution. The vials were analysed using the HPLC with the program described below. First one injection from the solvent blank tetrahydrofuran (THF) was made. Then three injections were measured from the reference item mix, three injections from the test item and again three injections from the reference item mix.

For each reference item, the capacity factor k was calculated from the retention time of thiourea and the retention time of the respective reference item.

A calibration function (log k versus log P_OW, linear fit) was determined using the literature values for P_OW of the reference items and the retention times in the six determinations.

 

The chromatogram of the test item gave two peaks that both eluted outside of the isocratic part of the method. Therefore, calculation of the log P_OWof the test item was not possible. The log P_OWof the test item is stated as > 6.50 (log P_OW of DDT, reference item with the highest log P_OW).

 

Peak	Mean Retention Time [min]	Mean Area [mAU*min]	Relative Area [%]	log POW
1	43.309	18.941	39.92	> 6.50
2	44.594	28.446	60.08

 

Description of key information

The key value is determined in an OECD guideline 117 study. The substance showed a longer retention time than DDT and is eluted outside of the isocratic part of the used method. Therefore, no exact log Pow could be determined. For the further assessment the log Pow of DDT is used.

Key value for chemical safety assessment

Log Kow (Log Pow):

6.5

at the temperature of:

25 °C