Registration Dossier

Physical & Chemical properties

Partition coefficient

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
from 2013-07-25 to 2013-07-30
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:
(2004)
Deviations:
yes
Remarks:
the test and reference substances were dissolved in methanol
Type of method:
HPLC method
Partition coefficient type:
octanol-water
Analytical method:
high-performance liquid chromatography
Key result
Type:
log Pow
Partition coefficient:
4.5
Temp.:
30 °C
pH:
7
Remarks on result:
other: 2,5-Dimethyl-2,5-di(tertbutylperoxy) hexyne-3, peak 1
Key result
Type:
log Pow
Partition coefficient:
5.7
Temp.:
30 °C
pH:
7
Remarks on result:
other: 2,5-Dimethyl-2,5-di(tertbutylperoxy) hexyne-3, peak 2
Key result
Type:
Pow
Partition coefficient:
35 000
Remarks on result:
other: 2,5-Dimethyl-2,5-di(tertbutylperoxy) hexyne-3, peak 1
Key result
Type:
Pow
Partition coefficient:
450 000
Remarks on result:
other: 2,5-Dimethyl-2,5-di(tertbutylperoxy) hexyne-3, peak 2

Table 3: Data retention time and corresponding log K, log Kow data

Substance

Log Kow theor.

Average net retention time (min)

Average log K

Thiourea

 

0

 

Aniline

0.9

0.46

-0.53

Methyl benzoate

2.1

1.55

0.00

Bromobenzene

3.0

3.69

0.38

Phenantrene

4.5

12.19

0.90

Fluoranthene

5.1

18.74

1.08

4,4‘-DDT

6.5

32.12

1.32

2,5-Dimethyl-2,5-di(tertbutylperoxy)

hexyne-3, peak 1

 

10.27

0.83

2,5-Dimethyl-2,5-di(tertbutylperoxy)

hexyne-3, peak 2

 

26.36

1.24

 

Conclusions:
In this study, a log Kow range of 4.5 to 5.7 was determined for the test item.
Executive summary:

The partition coefficient n-octanol/water (Kow) of 2,5-Dimethyl-2,5-di(tertbutylperoxy) hexyne-3 was estimated using the High Performance Liquid Chromatography (HPLC) method. The Kow test was performed in accordance with the OECD guideline 117 with a modification, the test and reference substances were dissolved in methanol. The data on the partition coefficient can be used to predict the adsorption on soil and sediments and for establishing quantitative structure-activity relationships for a wide range of biological effects.

No quantitative analytical method was required during this test. Only the determination of retention times of all substances was necessary.

The capacity factor k for each reference substance was calculated from the average measured retention time tR of the substance and the average retention time of thiourea (= t0 is the dead time, i.e. the average time a solvent molecule needed to pass the column). The partition coefficient octanol/water (Kow) was deduced from the capacity factor (k) using a calibration plot of Log Kow versus Log k of the selected reference substances.

During the test two peak responses for the test substance were detected.The average measured Log Kow value for 2,5-Dimethyl-2,5-di(tert-butylperoxy)hexyne-3, peak 1 as determined from the test was 4.5. The average measured Log Kow value for 2,5-Dimethyl- 2,5-di(tert-butylperoxy)hexyne-3, peak 2 as determined from the test was 5.7. 2,5-Dimethyl- 2,5-di(tert-butylperoxy)hexyne-3 had a Kow range of 3.5E+04 to 5.4E+05.

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2015-05-04 to 2015-06-09
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Remarks:
The determined log Pow (6.71) is outside the applicability domain of the HPLC method.
Qualifier:
according to guideline
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 830.7570 (Partition Coefficient, n-octanol / H2O, Estimation by Liquid Chromatography)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method A.8 (Partition Coefficient)
Deviations:
no
GLP compliance:
yes
Type of method:
HPLC method
Partition coefficient type:
octanol-water
Analytical method:
high-performance liquid chromatography
Key result
Type:
log Pow
Partition coefficient:
6.71
Temp.:
25 °C
pH:
7
Remarks on result:
other: The determined log Pow is outside the applicability domain of the HPLC method (0 < log Pow < 6).
Key result
Type:
Pow
Partition coefficient:
5 077 610
Temp.:
25 °C
pH:
7
Details on results:
The partition coefficient Pow was determined based on a calibration curve using 8 reference items. 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.

Measured and calculated data of DYBP-85-WO

Test Item name

Retention time (min)

Log k

Log Pow

Pow

Repeatability log unit

Calculated

DYBP-85-WO

41.77

1.263

6.71

5102340

0.01

41.76

1.263

6.71

5097538

41.75

1.263

6.71

5092740

41.73

1.263

6.71

5083153

41.63

1.262

6.70

5035417

41.67

1.262

6.70

5054471

Mean

41.72

1.263

6.71

5077610

-

Conf. Int. (95%)

0.06

-

0.002

28101

-

VC%

0.13

-

-

-

-

The determined log Pow: 6.71 ± 0.002 (95 % confidence interval).

The estimated Pow: 5077610 ± 28101 (95 % confidence interval).

The determined log Pow is outside the applicability domain of the HPLC method (0 < log Pow < 6). Therefore, the log Pow of DYBP-85-WO was stated to be log Pow > 6.5.*

*Remark: The log Pow value of the reference substance 4,4’-DDT as given in Regulation (EC) No. 440/2008, Annex Part A, Method A.8 (6.2) deviate from the value as given in the OECD TG 117 (6.5). As the determined log Pow is outside the applicability domain of the HPLC method this deviation was considered to have no influence on validity of the study result.

Conclusions:
The determined log Pow: 6.71 ± 0.002 (95 % confidence interval).
The estimated Pow: 5077610 ± 28101 (95 % confidence interval).
Executive summary:

In the course of this study the partition coefficient (Pow) of DYBP-85-WO was determined using high performance liquid chromatography (HPLC) method. A log Pow of 6.71 ± 0.002 (95 % confidence interval) and a Pow of 5077610 ± 28101 (95 % confidence interval) was estimated. The determined log Pow (6.71) is outside the applicability domain of the HPLC method (0 < log Pow < 6). Therefore, the log Pow of DYBP-85-WO was stated to be log Pow > 6.5.

Description of key information

The log Pow of DYBP-85-WO was determined using the HPLC method according to the OECD guideline 117 and EU method A.8. A log Pow of 6.71 ± 0.002 (95 % confidence interval) and a Pow of 5077610 ± 28101 (95 % confidence interval) was estimated. The determined log Pow (6.71) is outside the applicability domain of the HPLC method (0 < log Pow < 6). Therefore, the log Pow of DYBP-85-WO was stated to be log Pow > 6.5.

Key value for chemical safety assessment

Log Kow (Log Pow):
6.71
at the temperature of:
25 °C

Additional information

In the course of this study the partition coefficient (Pow) of DYBP-85-WO was determined using high performance liquid chromatography (HPLC) method. A log Pow of 6.71 ± 0.002 (95 % confidence interval) and a Pow of 5077610 ± 28101 (95 % confidence interval) was estimated. The determined log Pow (6.71) is outside the applicability domain of the HPLC method (0 < log Pow < 6). Therefore, the log Pow of DYBP-85-WO was stated to be log Pow > 6.5.

The partition coefficient n-octanol/water (Kow) of 2,5-Dimethyl-2,5-di(tertbutylperoxy) hexyne-3 was estimated using the High Performance Liquid Chromatography (HPLC) method. The Kow test was performed in accordance with the OECD guideline 117 with a modification, the test and reference substances were dissolved in methanol. The data on the partition coefficient can be used to predict the adsorption on soil and sediments and for establishing quantitative structure-activity relationships for a wide range of biological effects.

No quantitative analytical method was required during this test. Only the determination of retention times of all substances was necessary.

The capacity factor k for each reference substance was calculated from the average measured retention time tR of the substance and the average retention time of thiourea (= t0 is the dead time, i.e. the average time a solvent molecule needed to pass the column). The partition coefficient octanol/water (Kow) was deduced from the capacity factor (k) using a calibration plot of Log Kow versus Log k of the selected reference substances.

During the test two peak responses for the test substance were detected. The average measured Log Kow value for 2,5-Dimethyl-2,5-di(tert-butylperoxy)hexyne-3, peak 1 as determined from the test was 4.5. The average measured Log Kow value for 2,5-Dimethyl- 2,5-di(tert-butylperoxy)hexyne-3, peak 2 as determined from the test was 5.7. 2,5-Dimethyl- 2,5-di(tert-butylperoxy)hexyne-3 had a Kow range of 3.5E+04 to 5.4E+05.