(E)-1-(2,4,4-trimethyl-2-cyclohexen-1-yl)-2-buten-1-one

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 Jul 2017

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)

Version / remarks:

2004

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Remarks:

Staatliches Gewerbeaufsichtsamt Hildesheim, Germany

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Key result

Type:

log Pow

Partition coefficient:

3.59

Temp.:

23.9 °C

Remarks on result:

other: No pH value was measured for this mobile phase, because it is neutral. Furthermore the test item does not have functional groups with influence on the pH value of the mobile phase.

Remarks:

weighted mean of two test item signals.

Type:

log Pow

Partition coefficient:

>= 3.46 - <= 3.6

Temp.:

23.9 °C

Remarks on result:

other: No pH value was measured for this mobile phase, because it is neutral. Furthermore the test item does not have functional groups with influence on the pH value of the mobile phase.

Remarks:

range based on two test item signals.

Calibration

The retention time data of the reference items used for calibration are given in the following table.

Reference item	log POW	1st Calibration			2nd Calibration
		tR1 [min]	k	log k	tR2 [min]	k	log k
Nitrobenzene	1.9	2.130	2.76	0.441	2.138	2.78	0.444
Toluene	2.7	4.246	6.50	0.813	4.271	6.55	0.816
Ethylbenzene	3.2	6.175	9.91	0.996	6.198	9.95	0.998
Isopropylbenzene	3.7	8.616	14.2	1.15	8.646	14.3	1.16
1,2,4-T richlorobenzene	4.2	11.923	20.1	1.30	11.952	20.1	1.30
n-Butylbenzene	4.6	16.405	28.0	1.45	16.439	28.0	1.45
Dibenzyl	4.8	18.682	32.0	1.51	18.661	32.0	1.51

t_R1: Retention time of 1st Injection

t_R2: Retention time of 2nd Injection

k: Capacity factor reference item

log P_OW: Decadic logarithm of the Partition Coefficient (n-octanol / water)

 

The calculated slope, Y-intercept and correlation coefficient for the first and second calibration of the reference items are shown in the following table. The correlation coefficient r for both calibrations was > 0.9.

	1st Calibration	2nd Calibration
slope	2.774	2.781
Y-intercept	3.6020	3.5940
r^2	0.9928	0.9923
r	0.9964	0.9961

r: Correlation Coefficient

r²: Coefficient of determination

 

Results of Test Item Analysis

For each test item signal, two individual log P_OWvalues were derived under consideration of the first and second calibration and a mean value was calculated from these individual log P_OWvalues. The results are summarized in the following table.

	tR [min]	k	log k	log POW
				1st Calibration	2nd Calibration
Signal 1	6.898	11.2	1.05	3.46 ± 0.04 3.37 to 3.56 (95 % Cl)	3.46 ± 0.04 3.36 to 3.56 (95 % Cl)
	6.908	11.2	1.05
Mean	6.903	11.2	1.05	3.46
Signal 2	7.617	12.5	1.10	3.60 ± 0.04 3.51 to 3.70 (95 % Cl)	3.59 ± 0.04 3.50 to 3.69 (95 % Cl)
	7.627	12.5	1.10
Mean	7.622	12.5	1.10	3.60

t_r: Retention time

k: Capacity factor test item

P_OW: Partition Coefficient (n-octanol / water)

CI: Confidence Interval

 

The summarized results and weighted average mean are reported in the following table

	log POW			Area [%]
	1st Calibration	2nd Calibration	Mean
Signal 1	3.46 ± 0.04 3.37 to 3.56 (95 % Cl)	3.46 ± 0.04 3.36 to 3.56 (95 % Cl)	3.46	8.1
Signal 2 (main signal)	3.60 ± 0.04 3.51 to 3.70 (95 % Cl)	3.59 ± 0.04 3.50 to 3.69 (95 % Cl)	3.60	91.9
Weighted Mean			3.59

 

 

Conclusion

For each of the two test item signals, two individual log P_OW values were derived under consideration of the first and second calibration and a mean value was calculated from these individual log P_OW values. Finally, a weighted average mean value based on the peak area of the respective signals was calculated.

The mean column temperature was determined to be 23.9 °C during the course of the study.

The log P_OW of the test item was determined to be 3.46 for the first signal as well as 3.60 for the second (main) signal, with a weighted average mean value of 3.59.

Conclusions:

A partition coefficient of 3.59 (at 23.9 °C) was determined for the test substance according to OECD 117.

Executive summary:

According to OECD 117 (2004) and GLP, Log Kow of the test item was determined to be 3.59 at 23.9 °C via HPLC-method. The experiment resulted in a range of 3.46 -3.60 and a weighted average mean was obtained on the basis of the ratio of signals of the isomers.

Description of key information

Log P_OW: 3.59 at 23.9 °C (OECD 117, HPLC Method)

Key value for chemical safety assessment

Log Kow (Log Pow):

3.59

at the temperature of:

23.9 °C

Additional information

According to OECD 117 (2004) and GLP, Log Kow of the test item was determined to be 3.59 at 23.9 °C via HPLC-method. The experiment resulted in a range of 3.46 -3.60 and a weighted average mean was obtained on the basis of the ratio of signals of the isomers.