Nonanoic acid, mixed diesters, with oxybis[propanol] and dodecanoic acid

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The study was conducted according to an internationally recognised method. The substance is considered to be adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2004

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

no

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Remarks on result:

not determinable

Table: Wavelength, Run times and Retention times

Item	Wavelength (nm)	Run time (min)	Retention time (min)
Test item	210	70	17.166 / 46.323 *
Sodium nitrate	210	10	0.530
2-Butanone	250	5	0.973
Toluene	210	5	1.478
Phenanthrene	250	10	2.355
4,4-DDT	210	10	3.380

*Retention times of two separate test item signals; mean values of two samples at different concentrations

For each of the two test item signals, the capacity factors (retention times) were determined to be above the value of the reference item with the highest partition coefficient (Log Kow of 6.5 for 4,4 -DDT).

Therefore, the determination of the partition coefficient is not feasible.

Conclusions:

The partition coefficient log Kow of test item could not be determined according to OECD Guideline No. 117 due to a higher capacity factor (retention time) than the reference item with the highest capacity factor, corresponding to a partition coefficient log Kow> 6.5.

Executive summary:

A study was performed in order to determinate the partition coefficient n-octanol/water of test item according to OECD 117 guideline (HPLC method).

A preliminary testing was performed using 4 reference items. The partition coefficient log Kow of test item could not be determined according  to OECD Guideline No. 117 due to a higher capacity factor (retention time) than the reference item with the highest capacity factor, corresponding to a partition coefficient log Kow> 6.5.

Reference 2

Endpoint:

partition coefficient

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

supporting study

Study period:

June 2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Reason / purpose for cross-reference:

reference to other study

Qualifier:

no guideline followed

Principles of method if other than guideline:

not applicable

GLP compliance:

no

Type of method:

other: extrapolation calculated from results of study 181120TL / COH18483

Partition coefficient type:

octanol-water

Type:

log Pow

Partition coefficient:

12

Remarks on result:

other: extrapolated value for first signal of tets item

Type:

log Pow

Partition coefficient:

15.28

Remarks on result:

other: extrapolated value for second signal of test item

The retention time data of the reference items used for calibration are given in the following table:

Substance	Log Kow	Tr (min)	k	Log k
2-Butanone	0.3	0.973	0.836	-0.0779
Toluene	2.7	1.478	1.79	0.253
Phenanthrene	4.5	2.355	3.44	0.537
4,4-DDT	6.5	3.380	5.38	0.731

 

  

The calculated slope, Y-intercept and correlation coefficient for calibration of the reference itemsare shown below:

Slope	7.4613
Y-intercept	0.8082
R2	0.9923
r	0.9961

 

Two individual logPOW values were derived under consideration of the first and second calibration. Finally, a mean value was calculated from these individual logPOW values.

For first test item signal:

First signal	Tr (min)	Mean	k	Log k	Log Pow
5 g test item/L	17.029	17.166	31.4	1.50	12.00 ± 0.059.64 to14.36(95 % CI)
8.5 g/test item/L	17.303

 

For second test item signal:

Second signal	Tr (min)	Mean	k	Log k	Log Pow
5 g test item/L	46.536	46.323	86.4	1.94	15.28 ± 0.7512.06 to 18.50 (95 % CI
8.5 g/test item/L	46.109

 

Conclusions:

For an estimation, the obtained results were used for extrapolated values, corresponding to a log KOW of 12.00 for the first test item signal and a log KOW of 15.28 for the second signal, respectively. These values are likely to be over-estimated due to the relative wide extrapolation. However, the results indicate that the determination of the partition coefficient according to any other guideline, like OECD 107 (shake flask method) and OECD 121 (slow-stirring), is not feasible, as well. Therefore, these extrapolated values represent the closest possible result.

Executive summary:

For each of the two test item signals, the capacity factors (retention times) were determined to be above the value for the suggested reference item with the highest partition coefficient (log KOW of 6.5 for 4,4’-DT). Therefore, the determination of the partition coefficient is according to the guideline OECD No. 117 is not feasible.

For an estimation, the obtained results were used for extrapolated values, corresponding to a log KOW of 12.00 for the first test item signal and a log KOW of 15.28 for the second signal,respectively.

These values are likely to be over-estimated due to the relative wide extrapolation. However, the results indicate that the determination of the partition coefficient according to any other guideline,like OECD 107 (shake flask method) and OECD 121 (slow-stirring), is not feasible, as well.

Therefore, these extrapolated values represent the closest possible result.

Description of key information

The Log Kow of test item could not be determined according to OECD 117 guideline (HPLC method) because the capacity factor (retention time) of the two test item signals are higher than the highest capacity factor of reference items.

The values for the Lok Kow were extrapolated for an estimation for the two test item signals but these values are likely to be over-estimated due to the relative wide extrapolation.

First signal: Log Kow= 12

Second signal: Log Kow= 15.28

Additional information

A study according to OECD guidelines is not feasible. Therefore, an extrapolation (calculation) was performed in order to provide values for information.