Trans-2-{4-[difluoro(3,4,5-trifluorophenoxy)methyl]-3,5-difluorophenyl}-5-(trans-4-propylcyclohexyl)-1,3-dioxane

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02.09.2011 - 09.11.2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - HPLC Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

no

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

> 6.5

Temp.:

25 °C

pH:

6.1

Remarks on result:

other: estimated values: 9.5

Details on results:

The partition coefficient of the test item was estimated to be 9.5 at 25 °C.

Preliminary Visual Estimation of the n-Octanol Solubility

Different amounts of the test item were stirred with increasing amounts of n-octanol at room temperature and visually checked for any undissolved parts.

Table 1: Appearance of the test mixtures

Amount of the test item in g	Total amount of the test item in g	Volume n-octanol (total volume) in mL	Stirring time in min	Appearance of mixture	Solubility in g/L
0.0114	0.0114	1	30	undissolved	-
-	0.0114	11	125	dissolved	> 1.04
0.0188	0.0302	11	60	dissolved	> 2.75
0.1778	0.2080	11	75	dissolved	> 18.9

The solubility of the test item in n-octanol was > 18.9 g/L.

The partition coefficient Pow may be estimated from the saturation concentrations in n-octanol and water by the following equation:

Pow = cs(octanol) / cs(water)

 s = saturation

The preliminary water solubility of the test item was determined to be < 4.0 mg/L. Using this information and the determined solubility of the test item in n-octanol a partition coefficient > 3.7 was estimated. Therefore, the HPLC method was used in the main test.

ln addition the program kowwin (part of Episuite) was used for calculating the log Pow of the test item. The calculated value was 9.7.

HPLC-Method

Table 2: Determination of the Dead Time t0

Dead time marker	tR in min 1. measurement	tR in min 2. measurement	tR in min mean
Formamide	2.41	2.42	2.42

 

Table 3: Calibration data f from OECD guideline 117, adopted 2004)

Calibration substance	1. Inj tR (min)	2. Inj tR (min)	mean tR (min)	k	log k	log Pow
2-Butanone	2.68	2.68	2.68	0.11	-0.96	0.3
Acetanilide	2.70	2.71	2.71	0.12	-0.92	1.0
Cinnamyl alcohol	2.86	2.87	2.87	0.19	-0.73	1.9
2,6-Dicholoro- benzonitrile	3.18	3.19	3.18	0.32	-0.50	2.6
Allyl phenyl ether	3.74	3.74	3.74	0.55	-0.26	2.9
Benzophenone	3.54	3.54	3.54	0.47	-0.33	3.2
Cumene	4.94	4.94	4.94	1.05	0.02	3.7
Diphenyl ether	4.57	4.57	4.57	0.89	-0.05	4.2
Fluoroanthene	6.83	6.84	6.84	1.83	0.26	5.1
4,4’-DDT	8.34	8.35	8.35	2.45	0.39	6.5

Regression: logPow= a + b * logk
Parameters: a = 4.32, b = 3.84, r2 = 0.9501

 

Table 4: log Pow of the test item

	1. Inj. tR (min)	2. Inj. tR (min)	meantR (min)	k	logk	log Pow
Test Item	57.3	57.3	57.3	22.7	1.36	>6.5* (9.5)**

* above the highest log Pow value of calibration substances (DDT)
**via extrapolation

Conclusions:

The partition coefficient of the test item was estimated to be 9.5 at 25 °C.

Executive summary:

A study was conducted in accordance with OECD TG 117 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the HPLC method. The solubility of the test item in water and n-octanol was preliminary determined and a partition coefficient log Pow > 3.7 was calculated. Using the HPLC method for the main test, the value found for the partition coefficients n-octanol/water was above the highest log Pow values of the calibration curve, therefore, it was determined to be >6.5. After extrapolation the log Pow for the test item was estimated to be 9.5.

Description of key information

The partition coefficient of the test item was estimated to be 9.5 at 25 °C.

Key value for chemical safety assessment

Log Kow (Log Pow):

9.5

at the temperature of:

25 °C

Additional information

A study was conducted in accordance with OECD TG 117 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the HPLC method. The solubility of the test item in water and n-octanol was preliminary determined and a partition coefficient log Pow > 3.7 was calculated. Using the HPLC method for the main test, the value found for the partition coefficients n-octanol/water was above the highest log Pow values of the calibration curve, therefore, it was determined to be >6.5. After extrapolation the log Pow for the test item was estimated to be 9.5 (reference 4.7-1).