2H-Pyran, 2-[4'-[difluoro(3,4,5-trifluorophenoxy)methyl]-3',5'-difluoro[1,1'-biphenyl]-4-yl]-5-ethyltetrahydro-

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Version / remarks:

92/69/EC

Deviations:

no

Principles of method if other than guideline:

NA

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:

> 5.7

Temp.:

25 °C

pH:

7

Details on results:

The pH of the test solution was not measured. However, as the test substance is no acid/base and barely soluble, it has no influence on the pH. The pH of the HPLC solvents Acetonitrile and water are about pH7.

Table 1: Calibration data

Reference substance	1. Inj.tR in min	2. Inj. tR in min	3. Inj. tR in min	Mean value tR in min	k	logk	log Pow
Acetophenone	1.46	1.46	1.46	1.460	0.1870	-0.7282	1.7
Methylbenzoate	1.57	1.58	1.57	1.573	0.2791	-0.5542	2.1
Phenylbenzoate	1.87	1.87	1.87	1.870	0.5203	-0.2837	3.6
Biphenyl	2.26	2.26	2.26	2.260	0.8374	-0.0771	4.0
Phenanthrene	2.82	2.83	2.82	2.823	1.2954	0.1124	4.5
Triphenylamine	3.46	3.47	3.46	3.463	1.8157	0.2590	5.7
Formamide	1.23	1.23	1.23	1.230

Regression: log k = a + b * log Pow

Parameters: a = -1.1181 b = 0.2517 r = 0.985

 

Table 2: log Pow of the test substance

Test substance	1-Inj. tR in min	2. Inj. tR in min	3. Inj. tR in min	Mean value tR in min	k	logk	log Pow
	12.45	12.46	12.46	12.457	9.1274	0.9603	8.257

 

The retention time of the test item was significant greater than the retention time of the reference substance with the highest logarithmic partition coefficient of 5.7. The extrapolation of the curve parameters indicated for the test item an n-octanol/ water-partition coefficient at 25°C (± 2°C) of: log Pow = 8.26 Pow = 1.81E+08

Since the definition range of the calibration curve only covers the log Pow range from 1.7 to 5.7 the test result was evaluated as: log Pow > 5.7 Pow > 5.0E+05

Conclusions:

The log Pow of the test item was determined to be above 5.7.

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. Retention times tR were measured and averaged and the decimal logarithms of the capacity factors k were calculated. The linear regression parameters of the relationship log Pow = f(log k) were also calculated from the data obtained with the calibration mixture and, therewith, log Pow of the test substance was determined from its measured capacity factor.The retention time of the test item was significant greater than the retention time of the reference substance with the highest logarithmic partition coefficient of 5.7. The extrapolation of the curve parameters indicated for the test item an n-octanol/water-partition coefficient at 25°C (± 2°C) of: log Pow = 8.26. Since the definition range of the calibration curve only covers the log Pow range from 1.7 to 5.7 the test result was determined to be log Pow > 5.7.

Description of key information

The retention time of the test item was significant greater than the retention time of the reference substance with the highest logarithmic partition coefficient of 5.7. The extrapolation of the curve parameters indicated for the test item an octanol/water-partition coefficient at 25 °C of: log Pow = 8.26 (reference 4.7 -1).

Key value for chemical safety assessment

Log Kow (Log Pow):

8.26

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. Retention times tR were measured and averaged and the decimal logarithms of the capacity factors k were calculated. The linear regression parameters of the relationship log Pow = f(log k) were also calculated from the data obtained with the calibration mixture and, therewith, log Pow of the test substance was determined from its measured capacity factor.The retention time of the test item was significant greater than the retention time of the reference substance with the highest logarithmic partition coefficient of 5.7. The extrapolation of the curve parameters indicated for the test item an n-octanol/water-partition coefficient at 25°C (± 2°C) of: log POW = 8.26. Since the definition range of the calibration curve only covers the log Pow range from 1.7 to 5.7 the test result was determined to be log Pow > 5.7.