Ethyl ethyl(phenyl)carbamate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 6,2017 - March 14, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

ca. 2.28

Temp.:

20 °C

pH:

>= 6.39 - <= 6.83

Remarks on result:

other: Standart deviations ± 0.08

Details on results:

The content of EPU was calculated as follows: X=f*Ap / Cp
The f factor was calculated as follows: f= Cw*1000 / Aw
where:
X – content of the EPU, [g/kg];
f – factor;
Aw – average peak area of the EPU in the calibration solution;
Ap – average peak area of the EPU in the sample solution;
Cw – concentration of the EPU in calibration solution (per 100 %), [mg/mL];
Cp – concentration of the sample solution, [mg/mL];
1000 – calculation factor.
For the calculations the average peak area of EPU was taken from two determinations.

The test item stock solution was prepared in 1-octanol pre-saturated with water.The measured test item concentration in stock solution (1-octanol) was 5.3857g/kg (4.4432g/L). Density of 1-octanol (supplier data) is 0.825 g/L.

Table No.1: Calibration solution

Weight [mg]	Dilution [ml]	Cw [mg/ml]	Peak area		Average peak area Aw	f	Average  f
27.55	25-1-25-2-10	0.008287	489675	486690	488182.5	0.00001698	0.00001643
	25-1-25-3-10	0.012430	732520	733222	732871	0.00001696
	25-1-25-2-10	0.008287	490026	492069	491047.5	0.00001688
	25-1-25-0.2-10	0.000829	55055	56160	55607.5	0.00001490

Tble No.2: Study solution

Sample	Weight of the sample	Dilution	Cp	Peak area		Average peak area	X
	[mg]	[ml]	[mg/ml]			Ap	[g/kg]
1/w	997.8	10	99.775	14671	14587	14629	0.0024
2/w	1007.2	10	100.715	29392	29333	29362.5	0.0048
3/w	1003.8	10	100.38	45263	45536	45399.5	0.0074
4/w	1011.8	10	101.18	45625	45287	45456	0.0074
5/w	1003.4	10	100.34	22014	22167	22090.5	0.0036
6/w	1005.2	10	100.52	22149	22168	22158.5	0.0036
stock	159.8	10-1-10	1.598	524756	522950	523853	5.3857
1/o	160.05	10	16.005	959954	962318	961136	0.9866
2/o	76.40	10	7.640	459214	457204	458209	0.9853
3/o	81.05	10	8.105	740751	741657	741204	1.5024
4/o	84.85	10	8.485	781326	780544	780935	1.5121
5/o	81.25	10	8.125	371565	370395	370980	0.7501
6/o	80.95	10	8.095	369417	369815	369616	0.7501

Table No.3:Results of measurements at 20.0°C

Vial number	1	2	3	4	5	6
Temperature,°C	20.1		19.9		19.9
Volume of added stock solution, mL	1	1	1	1	1	1
Volume of water, mL	5	5	6.7	6.7	3.3	3.3
Volume of 1-octanol, mL	4	4	2.3	2.3	5.7	5.7
Volume 1-octanol phase/ volume of water phase	1:1		1:2		2:1
Ethyl ethyl(phenyl)carbamateconcentration in water phase, g/L	0.0024	0.0048	0.0074	0.0074	0.0036	0.036
Ethyl ethyl(phenyl)carbamateconcentration in 1-octanol phase, g/kg	0.9866	0.9853	1.5024	1.5121	0.7501	0.7501
Ethyl ethyl(phenyl)carbamateconcentration in 1-octanol phase, g/L	0.8139	0.8129	1.2395	1.2475	0.6188	0.6188
Mass ofEthyl ethyl(phenyl)carbamatein water phase∙10^3, g	0.0120	0.0240	0.0496	0.0496	0.0119	0.0119
Mass ofEthyl ethyl(phenyl)carbamatein 1-octanol phase∙10^3, g	4.0695	4.0645	4.0904	4.1168	4.1460	4.1460
Mass ofEthyl ethyl(phenyl)carbamatein both phases∙10^3, g	4.0815	4.0885	4.1400	4.1664	4.1579	4.1579
Added mass ofEthyl ethyl(phenyl)carbamate∙10^3, g	4.4432	4.4432	4.4432	4.4432	4.4432	4.4432

Table No.4: Measured pH values of water phase

Vial number	1	2	3	4	5	6
pH before test	6.22	6.22	6.22	6.22	6.22	6.22
pH after test	6.83	6.82	6.39	6.40	6.68	6.67

Table No.5: Calculated values of partition coefficient 1-octanol/water

Vial number	1	2	3	4	5	6
Volume 1-octanol phase/volume of water phase	1:1		1:2		2:1
Pow= C1-octanol/Cwater	339.1	169.4	167.5	168.6	171.9	171.9
log Pow= log(C1-octanol/Cwater)	2.53	2.23	2.22	2.23	2.24	2.24
Average log Pow+ standard deviation	2.38 ± 0.21		2.23 ± 0.01		2.24 ± 0.00
Average log Pow+ standard deviation	2.28±0.08

Conclusions:

Calculated value of partition coeficient 1-octanol/water (log Pow) at 20.0ºC and at pH 6.39 - 6.83 is 2.28±0.08.

Executive summary:

In accordance with OECD TG 107 and GLP study the determination of partition coefficient 1 -octanol/water at one pH value was determined using the flask method. The tested temperature was 20 ºC. First the presaturation of the solvents was needed. Two solvent 1-octanol and water (in various ratio) were shaked and then the phases were separted. After that, three tests were carried out. First one, 1 -octanol/:water=1:1, Second one (1:2) and third one(2:1). Test item stock solution wass prepared in 1 -octanol presaturated with water and analysed by HPLC. The concentrations of test item were determined in both phases. Calculated value of log Pow at temperature 20.0ºC and at pH 6.39 - 6.83  is 2.28±0.08.

Description of key information

Key study: OECD TG 107 and GLP study. Calculated value of partition coeficient 1-octanol/water (log Pow) at 20.0ºC and at pH 6.39-6.83  is 2.28±0.08 for the tested substance.

Key value for chemical safety assessment

Log Kow (Log Pow):

2.28

at the temperature of:

20 °C

Additional information

Key study: In accordance with OECD TG 107 and GLP study the determination of partition coefficient 1 -octanol/water at one pH value was determined. The tested temperature was 20 ºC. First the presaturation of the solvents was needed. Two solvent 1-octanol and water (in various ratio) were shaked and then the phases were separted. After that, three tests were carried out. The concentrations of test item were determined in both phases by HPLC method. The total quantity of the test item present in both phases was calculated and compared with the quantity of the substance originally introduced. pH of the aqueous phase before and after the experiment were measured. Calculated value of partition coeficient 1-octanol/water (log Pow) at 20.0ºC and at pH 6.39-6.83  was determinated as 2.28±0.08.