Fatty acids, tall-oil, polymers with glycidyl neodecanoate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015

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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

no

GLP compliance:

not specified

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

>= 2.4 - <= 5.1

Temp.:

25 °C

Remarks on result:

other: no information on pH available

Details on results:

The equation of the curve fitted to the calibration points was as follows: log k = 0.36697 x log Pow – 0.85887 (Rsq = 0.9923)

Table 2: Log K and log Pow of reference substances

Compound	Log K	Log Pow
Acetophenone	-0.2391	1.70
Naphthalene	0.4574	3.60
Diphenylether	0.6216	4.20
Phenanthrene	0.7999	4.50
Fluoranthene	0.9597	4.70
Triphenylamine	1.2314	5.70
DDT	1.3863	6.20

Correlation Results

Dead time is 1.385±0.001 min, with relative standard deviation (RSD) 0.04%.

The RSD of the retention times of the reference substances lay all below 0.25%.

 

Equation of the regression:

log k = 0.36697 * log P_OW – 0.85887

with a coefficient of determination r²= 0.9923

Log P_ow of test substance was calculated from the capacity factor as follows: log P_ow= (log K + 0.85887) / 0.36697

Table 3: Log Pow of test substance

Peak	Mean and standard deviation of 3 measurements	Log Pow
1	Mean	2.425
	Standard deviation	0.005
2	Mean	3.745
	Standard deviation	0.003
3	Mean	3.851
	Standard deviation	0.002
4	Mean	4.649
	Standard deviation	0.002
5	Mean	5.117
	Standard deviation	0.003

Validity:

All peaks of the test substance meet the validity criteria of OECD Guideline 117.

Conclusions:

The log Pow of the test substance was 2.4-5.1 at 25°C.

Executive summary:

A study was conducted to determine the partition coefficient of the test substance according to EU Method A.8 and OECD Guideline 107 (HPLC method). The determination was based on a calibration curve using 7 reference substances. Reference substances and test substance solutions were prepared in methanol. The concentration of test substance solution used for the measurements was 400 mg/L. Reference stock solution concentrations used were 1,000 μL/L (acetophenone, diphenylether) or 1,000 mg/L (thiourea, naphthalene, phenanthrene, fluoranthene, triphenylamine, DDT). Three injections were measured from the reference substance mix and the test substance, alternately. The retention times of the eight peaks of the reference substance mix and the test substance were used for further calculations. The capacity factors 'k' were calculated from the dead time and retention times of the reference substances. The log k data of the reference substances were plotted against their log Pow values. By plotting the log Pow values of the reference substances against the mean log capacity factors and performing linear regression, a calibration function was obtained. Further, with the calculated capacity factors for the test substance, each log Pow from the three determinations of the test substance was calculated. Finally, mean and standard deviation of the log Pow were calculated. Under the study conditions, the log Pow of the test substance was found to be 2.4 - 5.1 at 25°C (Johannes, 2015).

Description of key information

The partition coefficient was determined according to OECD Guideline 107 (HPLC method) (Johannes, 2015). 

Key value for chemical safety assessment

Log Kow (Log Pow):

5.1

at the temperature of:

25 °C

Additional information

The octanol/water partition coefficient was determined by an HPLC method using known substances as references. The chromatogram for the test substance yielded 5 peaks, for which the mean log Pow ranged from 2.4 to 5.1.