Di-tert-butyl 1,1,4,4-tetramethylbut-2-yn-1,4-ylene diperoxide

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

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

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:

4.5

Temp.:

30 °C

pH:

7

Remarks on result:

other: test item, peak 1

Key result

Type:

log Pow

Partition coefficient:

5.7

Temp.:

30 °C

pH:

7

Remarks on result:

other: test item, peak 2

Key result

Type:

Pow

Partition coefficient:

35 000

Remarks on result:

other: test item, peak 1

Key result

Type:

Pow

Partition coefficient:

450 000

Remarks on result:

other: test item, 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
Test item, peak 1		10.27	0.83
Test item, 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 the test item 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 test item, peak 1 as determined from the test was 4.5. The average measured Log Kow value for test item, peak 2 as determined from the test was 5.7. The test item had a Kow range of 3.5E+04 to 5.4E+05.

Reference 2

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 the test item

Test Item name	Retention time (min)	Log k	Log Pow	Pow	Repeatability log unit
		Calculated
Test item	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 the test item 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 the test item 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 the test item was stated to be log Pow > 6.5.

Description of key information

The log Pow of the test item 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 the test item 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 the test item 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 the test item was stated to be log Pow > 6.5.

The partition coefficient n-octanol/water (Kow) of the test item 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 the test item, peak 1 as determined from the test was 4.5. The average measured Log Kow value for the test item, peak 2 as determined from the test was 5.7. The test item had a Kow range of 3.5E+04 to 5.4E+05.