1-Ethoxy-2,3-difluor-4-[4-(trans-4-propylcyclohexyl)-1-cyclohexen-1-yl]-benzene

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18.11.2010-29.11.2010

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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Version / remarks:

2008

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:

> 6.5

Temp.:

25 °C

Remarks on result:

other: pH not relevant, as test item does not dissociate in water

Preliminary visual estimation of the water solubility

Different amounts of the test item and water were stirred at room temperature until the mixture appeared dissolved or the water solubility could be estimated to be below 10 mg/L.

 

Table 1: Appearance of the test mixtures

Amount of the test item in mg	Total volume in mL	Appearance of mixture
17.0	100	Undissolved 1)
9.45	500	Undissolved 1)
4.69	500	Undissolved 1)

1) After adding the indicated amount of water, the solution was stirred at room temperature for about 3 days.

The solubility of the test item in water is below 9.4 mg/L (without correction of the purity).

 

Preliminary visual estimation of the n-octanol solubility

About 129 mg of the test item were stirred with increasing volumes of n-octanol at room temperature and visually checked for any undissolved parts.

 

Table 2: Appearance of the test mixtures

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
0.129	1	25	undissolved	< 129
0.129	2	70	undissolved	< 64.6
0.129	7	45	Dissolved	> 18.5

The solubility of the test item in n-octanol is between 18.5 and 64.6 g/L (without correction of the purity).

 

Calculation of the partition coefficient log Pow

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

Pow  = Csoctanol / Cswater

s = saturation

With the data obtained the partition coefficient was calculated as: log Pow > 3.3. Therefore, the partition coefficient n-octanol/water of the test item at room temperature was determined by the HPLC-method.

In addition the program kowwinnt (part of episuite from SRC) was used for calculating the log Pow of the test item. The EPI (Estimation Programs Interface) Suite was developed by the EPA's Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC). The calculated value was 9.8 for the test item.

 

HPLC-Method

Table 3: Determination of the Dead time t0

Dead time marker	tR in min 1. measurement	tR in min 2. measurement	tR in min mean
Formamide	1.27	1.27	1.27

 

Dead time:      t0 = 1.27 min

 

Table 4: Calibration data (*from OECD guideline 117, adopted 2004)

Calibration substance	1. lnj. tR in min	2. lnj. tR in min	mean tR in min	k	log k	log Pow
2-butanone	1.46	1.46	1.46	0.15	-0.84	0.3
Acetanilide	1.44	1.44	1.44	0.13	-0.88	1.0
Cinnamyl alcohol	1.54	1.54	.154	0.21	-0.67	1.9
2,6-dichlorobenzonitrile	1.8	1.8	1.8	0.42	-0.38	2.6
Allyl phenyl ether	2.18	2.18	2.18	0.72	-0.15	2.9
Benzophenone	2.01	2.01	2.01	0.58	-0.24	3.2
Cumene	2.98	2.97	2.98	1.34	0.13	3.7
Diphenyl ether	2.73	2.72	2.73	1.15	0.06	4.2
Fluoranthene	5.36	5.36	5.36	3.22	0.51	5.1
4,4' DDT	4.77	4.76	4.75	2.75	0.44	6.5

 

Regression: log Pow = a + b * logk

Parameters: a = 33.86

b = 3.58

r2 = 0.9125

 

Table 5: log Pow of the test item

	1. lnj. tR in min	2. lnj. tR in min	m ean tR in min	k	log k	log Pow
Test ltem	77.8	79.8	78.8	61.0	1.79	>6.5*1 (10.3)*2

*1: above the highest log Pow value of calibration substances (DDT)

*2: via extrapolation

Conclusions:

The partition coefficient n-octanol/water (log Pow) of the test substance was determined to be > 6.5.

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 n-octanol/water partition coefficient of the test substance was derived from its retention time and the calibration graph. The retention time of the test item was above the retention time of the highest calibration standard and thus out of the calibration range. Therefore, the partition coefficient n-octanol/water (log Pow) of the test substance was determined to be > 6.5.

Description of key information

The partition coefficient n-octanol/water (log Pow) of the test substance was determined to be > 6.5.

Key value for chemical safety assessment

Log Kow (Log Pow):

6.5

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 n-octanol/water partition coefficient of the test substance was derived from its retention time and the calibration graph. The retention time of the test item was above the retention time of the highest calibration standard and thus out of the calibration range. Therefore, the partition coefficient n-octanol/water (log Pow) of the test substance was determined to be > 6.5.