Registration Dossier

Administrative data

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

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
HPLC method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficient
Key result
Type:
log Pow
Partition coefficient:
> 6.5
Temp.:
25 °C
pH:
> 5 - < 6

Applicant's summary and conclusion

Conclusions:
The correlation log k / log POW was used for the calculation of the log POW of the compo-nents of test item Palmitoyl grapevine shoot extract. Due to the fact that the calculated log POW of the three peaks was higher than the highest log POW of the reference items (DDT with log POW 6.5) the log POW of these peaks is stated as > 6.5.

The test item peaks showed retention times of 40.1 – 43.4 min with a very low standard deviation of 0.005 - 0.014 min. The determination was precise. The calculation of the log POWs of the test item peaks is not possible, because the peaks eluted not in the isocratic part of the HPLC program. Extrapolation is not possible therefore. Because the retention time of the test item peaks were higher than the retention time of DDT (18.5 minutes) the log POW of the test item is stated as > 6.5 (log POW of DDT).
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 Pow are correlated. The reference items were chosen on behalf 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. For the measurement of the test item after the retention time of DDT the mobile phase was changed to 100 % isopropanol. The mobile phase was changed to 100 % isopropanol to show, that the test item peak is detectable and is eluted from the HPLC column after DDT.

First one injection from the solvent blank isopropyl alcohol and isopropyl alcohol/water/methanol 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 Pow, linear fit) was determined using the literature values for Pow of the reference items and the retention times in the six determinations.

In the main test the 3 test item peaks showed a retention time of 40.1 – 43.4 minutes with a very low standard deviation of 0.005 - 0.014 min. The determination was precise. The calculation of the log Pow of the test item peaks is not possible, because the peaks eluted not in the isocratic part of the HPLC program. Extrapolation is not possible therefore. Because the retention times of the test item peaks are higher than the retention time of DDT (18.5 minutes) the log Pow of the test item is stated as> 6.5(log Pow of DDT).