(4E)-5-cyclohexyl-2,4-dimethylpent-4-enal

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27-03-2018 to 05-09-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP. All relevant validity criteria were met.

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected: June 2016 ; signature: January 2017

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

photometric method

Type:

log Pow

Partition coefficient:

4.38

Temp.:

22.2 °C

pH:

ca. 7

HPLC method

The mean void time (t0) was determined to be 0.537 minutes.

The results of the HPLC method are given in the Table 3. The calibration curves of the log k of the reference substances as function of log Pow had an regression line represented by the equations:

Calibration 1: log Pow = 2.9820 × log k + 0.8043 (r = 0.9861, n = 14 and r2 = 0.9930).

Calibration 2: log Pow = 2.9867 × log k + 0.7981 (r = 0.9861, n = 14 and r2 = 0.9930).

 

Table 2. Calibration data

Reference item	log POW	1st Calibration			2nd Calibration
		tR1 [min]	k	log k	tR2 [min]	k	log k
Benzonitrile	1.6	1.385	1.58	0.198	1.389	1.59	0.200
Nitrobenzene	1.9	1.815	2.38	0.377	1.820	2.39	0.378
Toluene	2.7	3.247	5.05	0.703	3.254	5.06	0.704
Ethylbenzene	3.2	4.411	7.21	0.858	4.419	7.23	0.859
Isopropylbenzene	3.7	5.787	9.78	0.990	5.796	9.79	0.991
1,2,4-Trichlorobenzene	4.2	7.816	13.6	1.13	7.816	13.6	1.13
n-Butylbenzene	4.6	10.074	17.8	1.25	10.067	17.7	1.25
Dibenzyl	4.8	10.998	19.5	1.29	10.998	19.5	1.29

tR1: Retention time 1. Injection

tR2: Retention time 2. Injection

log k: Common logarithm of the Capacity factor reference item

log POW: Common logarithm of the Partition Coefficient (n-octanol / water)

 

Table 3. Test item determination

Test Item		tR [min]	k	log k	log POW
					1st Calibration	2nd Calibration
		9.139	16.0	1.20	4.38 ± 0.07 4.20 to 4.56 (95 % CI)	4.38 ± 0.07 4.20 to 4.56 (95 % CI)
		9.133	16.0	1.20
	Mean	9.136	16.0	1.20	4.38

tR : Retention time

k : Capacity factor test item

POW : Partition Coefficient (n-octanol / water)

CI : Confidence Interval

Conclusions:

The partition coefficient of the test item was determined to be log Pow = 4.38 at 22.2 °C and ca. pH 7.0

Executive summary:

The n-octanol-water partition coefficient was determined using theHPLC method of OECD Method 117 and EU Method A.8 under GLP. The test was performed with a concentration of 100 mg test item/L in 75 % methanol : 35 % HPLC water. Samples of the test item were analysed via HPLC on a C18 column with diode array detection. Calibration was performed using eight reference items with known log Pow values (given by the guidelines). The reference items were measured twice, once before and once after the measurement of the test item, for which one replicate was double injected. The void time of the HPLC system was determined with sodium nitrate. Two individual log Pow values for each of the single chromatographic resolved test item signals were derived under consideration of the first and second calibration. Finally, a mean value was calculated from these individual log Pow values. The log Pow was 4.38 ± 0.07. The partition coefficient of the test item was determined to be log Pow = 4.38 at mean temperature 22.2 °C and approximately neutral pH.

Reference 2

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08-07-2020 to 21-09-2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP. All relevant validity criteria were met.

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Calibration reference substances were injected singularly rather than simultaneously. Expert judgement indicates this is not a significant deviation in that the standards retention times should not be impacted.

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

yes

Remarks:

see above

GLP compliance:

yes

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

4.39

Temp.:

22 °C

pH:

ca. 7

Remarks on result:

other: mean log Pow; (n=2)

HPLC method

The mean void time (t0) was determined to be 0.648 minutes.

The results of the HPLC method are given in the Table 3. The calibration curves of the log k’ of the reference substances as function of log Pow had a regression line represented by the equations:

Calibration: log k’ = 0.3362 × log Pow – 0.3797 (n = 8 and r2 = 0.9843).

 

Table 2. Calibration data

Reference Item	CAS Number	Retention Time (min)			Capacity Factor (k')	Log10 k'	Log10 Pow
		Injection 1	Injection 2	Mean
Benzonitrile	100-47-0	1.409	1.419	1.414	1.183	0.07307	1.6
Nitrobenzene	98-95-3	1.842	1.842	1.842	1.844	0.26577	1.9
Toluene	108-88-3	3.212	3.207	3.210	3.955	0.59720	2.7
Ethylbenzene	100-41-4	4.315	4.320	4.318	5.666	0.75329	3.2
Isopropylbenzene	98-82-8	5.646	5.641	5.644	7.714	0.88726	3.7
1,2,4-Trichlorobenzene	120-82-1	7.527	7.536	7.536	10.629	1.02648	4.2
n-Butylbenzene	104-51-8	9.708	9.723	9.716	14.001	1.14615	4.6
Dibenzyl	103-29-7	10.690	10.709	10.700	15.520	1.19089	4.8

 

Table 3. Test item determination

Peak	Injection	Retention Time (min)	Capacity Factor (k')	Log10 k'	Log10 Pow	Mean Log10 Pow
1	1	8.712	12.451	1.0952	4.39	4.39
1	2	8.717	12.459	1.0955	4.39

Conclusions:

The partition coefficient of the test item was determined to be log Pow = 4.39 at 22°C and ca. pH 7.0

Executive summary:

The n-octanol/water partition coefficient was determined using the HPLC method within OECD TG 117 and EU Method A.8 in accordance with GLP. The test was performed with a nominal concentration of 50 mg test item/L injected at 5 µL with a mobile phase of 75% methanol : 25% HPLC water. Samples of the test item were analysed via HPLC on a C18 column with variable wavelength detector. Calibration was performed using eight reference items with known log POW values (given by the guidelines). The dead time of the HPLC system was determined with sodium nitrite. The dead time and the reference items were measured in duplicate. The test item was injected and measured in duplicate. One individual partition coefficient value of the resolved chromatographic test item signals was derived for each injection. A mean value was calculated from the individual log Pow values. The partition coefficient of the test item was determined to be log Pow 4.39 at a mean temperature 22°C and approximately neutral pH.

Description of key information

Log Pow = 4.39, at 22 ±0.8 °C and ca. pH 7.0, HPLC method, OECD TG 117, 2020

Supporting data:

Log Pow = 4.38 ± 0.07 at 22.2 °C and ca. pH 7.0, HPLC method, OECD TG 117, 2018

Key value for chemical safety assessment

Log Kow (Log Pow):

4.39

at the temperature of:

22 °C

Additional information

Key study : OECD TG 117, 2018 : The n-octanol-water partition coefficient was determined using theHPLC method of OECD Method 117 and EU Method A.8 under GLP. The test was performed with a concentration of 100 mg test item/L in 75 % methanol : 35 % HPLC water. Samples of the test item were analysed via HPLC on a C18 column with diode array detection. Calibration was performed using eight reference items with known log Pow values (given by the guidelines). The reference items were measured twice, once before and once after the measurement of the test item, for which one replicate was double injected. The void time of the HPLC system was determined with sodium nitrate. Two individual log Pow values for each of the single chromatographic resolved test item signals were derived under consideration of the first and second calibration. Finally, a mean value was calculated from these individual log Pow values. The log Pow was 4.38 ± 0.07. The partition coefficient of the test item was determined to be log Pow = 4.38 at mean temperature 22.2 °C and approximately neutral pH.

Key study : OECD TG 117, 2020 : The n-octanol/water partition coefficient was determined using the HPLC method within OECD TG 117 and EU Method A.8 in accordance with GLP. The test was performed with a nominal concentration of 50 mg test item/L injected at 5 µL with a mobile phase of 75% methanol : 25% HPLC water. Samples of the test item were analysed via HPLC on a C18 column with variable wavelength detector. Calibration was performed using eight reference items with known log POW values (given by the guidelines). The dead time of the HPLC system was determined with sodium nitrite. The dead time and the reference items were measured in duplicate. The test item was injected and measured in duplicate. One individual partition coefficient value of the resolved chromatographic test item signals was derived for each injection. A mean value was calculated from the individual log Pow values. The partition coefficient of the test item was determined to be log Pow 4.39 at a mean temperature 22°C and approximately neutral pH.