5-Brom-2-[(3,4,5-trifluorphenoxy)-difluormethyl]-1,3-difluorbenzene

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03.04. - 15.08.06

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)

GLP compliance:

yes (incl. QA statement)

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

Calibration and measurement:

To create the regression line, two measurements (each with three injections) were carried out from the reference substance mix and the formamide standard and the corresponding retention times were determined. The respective logarithmic mean values ​​of the capacity factors were then subjected to a regression analysis using the known log Pow. The distribution coefficient of the test substance was determined from the retention times using the associated capacity factors and the constants of the regression equations. The measurement data can be found in the below tables. The log Pow values ​​determined for the two measurements were in the range of +/- 0.1 log units, so that the test result can be classified as valid.

Table 1: Calibration data (1st measurement)

Reference substance	1st Injection, retention time in min	2nd Injection, retention time in min	3rd Injection, retention time in min	mean value retention time in min	k	log k	log Pow
Acetophenone	3.02	3.04	3.00	3.020	0.3707	-0.4310	1.7
Methylbenzoate	3.63	3.63	3.59	3.617	0.6415	-0.1928	2.1
Phenylbenzoate	5.69	5.64	5.54	5.623	1.5522	0.1909	3.6
Biphenyl	8.96	8.87	8.71	8.847	3.0151	0.4793	4.0
Phenanthrene	13.94	13.73	13.51	13.727	5.2300	0.7185	4.5
Triphenylamin	19.51	18.95	18.59	19.017	7.6309	0.8826	5.7
Substance for t0 determination
Formamide	2.19	2.20	2.22	2.203

Regression equation: log k = a + b * log Pow

Parameter: a = -0.9425

b = 0.3381

r = 0.982

Table 2: log Pow of test item (1st measurement)

Test item	1st Injection, retention time in min	2nd Injection, retention time in min	3rd Injection, retention time in min	mean value retention time in min	k	log k	log Pow
Art. 276852	23.33	23.34	23.36	23.343	9.5946	0.9820	5.69

Table 3: Calibration data (2nd measurement

Reference substance	1st Injection, retention time in min	2nd Injection, retention time in min	3rd Injection, retention time in min	mean value retention time in min	k	log k	log Pow
Acetophenone	3.00	2.98	3.01	2.997	0.3621	-0.4411	1.7
Methylbenzoate	3.58	3.56	3.59	3.577	0.6258	-0.2036	2.1
Phenylbenzoate	5.48	5.48	5.52	5.493	1.4970	0.1752	3.6
Biphenyl	8.58	8.59	8.64	8.603	2.9106	0.4640	4.0
Phenanthrene	13.25	13.29	13.36	13.300	5.0455	0.7029	4.5
Triphenylamin	18.19	18.29	18.40	18.293	7.3152	0.8642	5.7
Substance for t0 determination
Formamide	2.19	2.19	2.22	2.200

Regression equation: log k = a + b * log Pow

Parameter: a = -0.9493

b = 0.3360

r = 0.982

Table 4: log Pow of test item (2nd measurement)

Test item	1st Injection, retention time in min	2nd Injection, retention time in min	3rd Injection, retention time in min	mean value retention time in min	k	log k	log Pow
Test item	22.70	22.75	22.80	22.750	9.3409	0.9704	5.71

The following final log Pow values of the test item were determined by extrapolation from the measured values:

1st measurement: log Pow = 5.69 , Pow = 4.93E+05

2nd measurement: log Pow = 5.71 , Pow = 5.17E+05

Mean value: log Pow = 5.7 , Pow = 5.05E+05

Conclusions:

The partition coefficient n-octanol/water of the test item was determined according to the HPLC method. It was found to be: log Pow = 5.7 at 25 °C.

Executive summary:

A study was conducted in accordance with Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the HPLCmethod. The n-octanol/water partition coefficient of the test substance was derived from its retention time and the calibration graph. Therefore, the partition coefficient n-octanol/water of the test substance was determined to be 5.7 at 25 °C.

Description of key information

A study was conducted in accordance with Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the HPLCmethod. The n-octanol/water partition coefficient of the test substance was derived from its retention time and the calibration graph. Therefore, the partition coefficient n-octanol/water of the test substance was determined to be 5.7 at 25 °C.

Key value for chemical safety assessment

Log Kow (Log Pow):

5.7

at the temperature of:

20 °C