3-methyl-5-phenylpent-2-enenitrile

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-09-24

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

2.81

Temp.:

23.6 °C

pH:

7

Remarks on result:

other: Isomer 1

Type:

log Pow

Partition coefficient:

2.98

Temp.:

23.6 °C

pH:

7

Remarks on result:

other: Isomer 2

Key result

Type:

log Pow

Partition coefficient:

2.93

Temp.:

23.6 °C

pH:

7

Remarks on result:

other: weighted mean partition coefficient

Details on results:

The HPLC void time (t0) was determined by threefold injection of a solution of 5 mg/L NaNO3. The slope, Y-intercept and correlation coefficient for the first and second calibration of the reference were calculated. The correlation coefficient r for both calibrations was > 0.9.
Two individual log Pow of the test item values were derived under consideration of the first and second calibration. Finally, a mean value was calculated from these individual log Pow values.

An individual log Pow value of 2.66 to 2.97 (95 % Cl) was obtained with the first and 2.66 to 2.97 (95 % Cl) was obtained with the second calibration for Isomer 1 and .an individual log Pow value 2.82 to 3.14 (95% Cl) was obtained with the first and 2.82 to 3.14 (95 % Cl) was obtained with the second calibration for Isomer 2.
The individual values did not differ more than ± 0.1 log Pow units. Based on these data a mean log Pow value of 2.81 for isomer 1 and 2.98 for isomer 2 was derived.

Due to technical reasons, standards were injected separately instead of simultaneously. This was considered to have no impact on the validity of the study results.

Calibration Data of the Reference Items

Reference item	log Pow	1st Calibration			2nd Calibration
		tR1 [min]	k	log k	tR2 [min]	k	log k
Benzonitrile	1.6	2.366	3.79	0.579	2.369	3.80	0.580
Nitrobenzene	1.9	2.979	5.03	0.702	2.983	5.04	0.702
Methyl benzoate	2.1	3.188	5.45	0.736	3.189	5.46	0.737
Toluene	2.7	5.896	10.9	1.04	5.893	10.9	1.04
Ethylbenzene	3.2	8.863	16.9	1.23	8.866	16.9	1.23
Phenyl benzoate	3.6	8.786	16.8	1.23	8.793	16.8	1.23
Biphenyl	4.0	13.148	25.6	1.41	13.144	25.6	1.41

tR1 : Retention time 1. Injection

tR2 : Retention time 2. Injection

k : Capacity factor reference item

log Pow : Partition Coefficient (n-octanol / water)

 

Retention Times, Capacity Factors and Partition Coefficients of Isomer 1

Test item	tR1 [min]	k	log k	log Pow
				1st Calibration	2nd Calibration
	5.683	10.5	1.02	2.81 ±0.06 2.66 to 2.97 (95 % Cl)	2.81 ± 0.06 2.66 to 2.97 (95 % Cl)
	5.678	10.5	1.02
Mean	5.681	10.5	1.02	2.81

 

 Retention Times, Capacity Factors and Partition Coefficients of Isomer 2

Test item	tR1 [min]	k	log k	log Pow
				1st Calibration	2nd Calibration
	6.353	11.9	1.08	2.98 ± 0.06 2.82 to 3.14 (95% Cl)	2.98 ± 0.06 2.82 to 3.14 (95 % Cl)
	6.347	11.8	1.07
Mean	6.350	11.9	1.08	2.98

 

1st calibration:

slope: 2.813; y-intercept: -0.0546; r2 0.9973

2nd calibration

slope: 2.816; y--intercept: -0.0586; r2 0.9974

 

 

Conclusions:

The partition coefficient log Pow of the test substance was determined to be log Pow = 2.81 for isomer 1 and 2.98 for isomer 2 at 23.6 °C.

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 partition coefficient Pow was determined in two individual measurements. Therefore a stock solution of the test item in acetonitrile was prepared. A test solution was prepared by dilution the mobile phase (50 % acetonitrile and 50 % water (v/v)). The resulting solution of 10 mg/L and pH 7 was directly measured via HPLC-UV at 23 ± 1 °C. The reference items were measured twice, once before and once after the measurement (double injection of one replicate) of the test item. The void time of the HPLC system was determined with sodium nitrate. For each reference item, the capacity factor K was calculated from the retention time of sodium nitrate and the retention time of the respective reference item. A calibration function (log K versus log Pow, linear fit) was determined using the literature values for Pow of the reference items and the retention times in the six determinations. Two individual log Pow values for the test item were derived under consideration of the first and second calibration. Finally, a mean value was calculated from these individual log Pow values. The coefficient of determination r2 of the calibration function log K/Log Pow was calculated to be 0.9873 and 0.9874 respectively. According to the guideline criteria this value was considered as sufficient to use the calibration function for the determination of the log Pow of the test item. The retention time of the test item lied within the range of the reference items. The partition coefficient log Pow of the test substance was determined to be log Pow = 2.81 for isomer 1 and 2.98 for isomer 2 at 23.6 °C and pH=7.

Description of key information

The partition coefficient log Pow of the test substance was determined to be log Pow = 2.81 for isomer 1 and 2.98 for isomer 2 at 23.6 °C.

Key value for chemical safety assessment

Log Kow (Log Pow):

2.98

at the temperature of:

23.6 °C

Additional information

A study was conducted in accordance with OECD TG 117 determine the partition coefficient of the test substance. Using the HPLC method partition coefficient Pow was determined in two individual measurements at 23 ± 1 °C. A calibration function (log K versus log Pow, linear fit) was determined using the literature values for Pow of the reference items and the retention times in the six determinations. The retention time of the test item lay within the range of the reference items. The partition coefficient log Pow of the test substance was determined to be log Pow = 2.81 for isomer 1 and 2.98 for isomer 2 at 23.6 °C and pH=7. For risk assessment a worst case logPow of 2.98 was used as key value.