Amines, C12-14-branched alkyl, dodecylbenzenesulfonates (1:1)

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

16 January 2018 - 26 March 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Remarks:

Study was conducted in accordance with international guidelines and in accordance with GLP. All guideline validity criteria were met.

Qualifier:

according to guideline

Guideline:

other: EU Method A.8. (Partition Coefficient - Estimation Method (Solubility Ratio))

Version / remarks:

Regulation (EC) 440/2008 of 30 May 2008

GLP compliance:

yes (incl. QA statement)

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Analytical method:

other: Not applicable

Key result

Type:

log Pow

Partition coefficient:

>= 2.4 - <= 3

Temp.:

20.8 °C

Remarks on result:

other: pH not measured

Data Evaluation

The partition coefficient is estimated from the ratio of the solubilities of the test item in the pure solvents.

P_{ow estimate} = saturation c_n-octanol / saturation c_water

Table 1:       Solubility in n-octanol (at 20.8 °C)

Weight of Test Item (mg)	Volume n-octanol	Duration of Shaking	Remarks
50.7 mg	5 ml	10 min	not dissolved
	10 ml	10 min	dissolved completely no light scattering

The n-octanol solubility of the test item was determined to be 5,070 mg/L – 10,140 mg/l.

The water solubility of the test item was determined using a method designed to be compatible with EU A.6. (preliminary test method)⁽¹⁾, a range value was determined of 10 – 22 mg/l at 20 ℃ ± 2 ℃.  Note, due to the complex and surface active nature of the test item, it was not technically possible to apply either the shake flask or column elution method and progress beyond the preliminary test.

Based on the above results the maximum and minimum estimated Pow can be calculated as:

P_{ow max} = maximum saturation concentration n-octanol/minimum saturation concentration water = 10,140 mg/l / 10 mg/l = 1,014.

Log P_{ow max} = Log 1,014 = 3.01.

P_{ow min} = minimum saturation concentration n-octanol/maximum saturation concentration water = 5,070 mg/L / 22 mg/l = 230.5.

Log P_{ow min} = Log 230.5 = 2.36.

Therefore, the log POW is estimated to be between 2.4 and 3.0 at 20.8 °C.

(1) BÄR, C. (2017): Water Solubility of Amines, C12-14-branched alkyl, dodecylbenzenesulfonates (1:1)

Conclusions:

The partition coefficient of the test item was estimated to be Log Pow = 2.4 - 3.0 at a temperature of 20 ± 2.0 °C.

Executive summary:

EU Method A.8. – The partition coefficient of the test item was determined using the estimation method (solubility ratio).  The procedures employed were designed to be compatible with Method A.8., partition coefficient, of Commission Regulation (EC) No 440/2008 of 30 May 2008.

An aliquot of test item (50.7 mg) was placed in a glass vessel, n-octanol was added in a stepwise manner.  After each addition of n-octanol, the vessel was shaken for at least 10 min.  The sample was then visually checked for undissolved test item.  If the test item was not dissolved further n-octanol was added in the manner previously described.  The test was performed at 20.8 ℃.

For the test item an estimated partition coefficient of log Pow = 2.4 - 3.0 at a temperature of 20 ± 2.0 °C was determined.

Reference 2

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

16 January 2018 - 23 March 2018

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

unsuitable test system

Remarks:

Whilst the study has been conducted according to the guideline method under GLP conditions. The test item is a complex substance that has been determined to be surface active. As such this study must be regarded as not reliable. The nature of the test item means that there is the potential for secondary column interactions to occur, leading to a potential overestimation of the partition coefficient. To mitigate against this phenomenon, this study is being used as a part of a weight of evidence for this endpoint.

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Regulation (EC) 440/2008 of 30 May 2008

Deviations:

yes

Remarks:

The study was conducted on a surface active substance.

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

April 2004

Deviations:

yes

Remarks:

The study was conducted on a surface active substance.

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

other: N/A - Partition coefficient determined by HPLC method.

Key result

Type:

log Pow

Partition coefficient:

>= 1.77 - <= 5.42

Temp.:

20 °C

pH:

7.03

Remarks on result:

other: Mean Value

Remarks:

Two measurements were made under identical conditions, using the same set of reference items that fall within a range of ± 0.1 log units. Therefore the quality criteria outlined in OECD 117 have been fulfilled.

Data Evaluation

Calculation of log k – The corresponding logarithms of the capacity factors, log k, were calculated from the retention times and the dead time.

Calibration Graph – A correlation graph of log k versus log Pow was plotted.

Sample Results – The partition coefficient of the test item was obtained by interpolation from the calibration graph, using the calculated capacity factor.

 

 

Table 3:          Retention time and log Pow of the test item (mean of two runs)

	Retention time [min]	Mean retention time [min]	Mean retention time of two runs [min]	Absolute deviation [min]	Log POWdetermined	Mean log POW	Mean log Powof two runs	Absolute deviation of log Pow
Run 1 – Injection 1 (Peak Start)	2.634	2.630	2.63	0.01	1.77	1.77	1.77	0.01
Run 1 – Injection 2 (Peak Start)	2.631				1.77
Run 1 – Injection 3 (Peak Start)	2.628				1.77
Run 1 – Injection 4 (Peak Start)	2.627				1.77
Run 2 – Injection 1 (Peak Start)	2.626	2.622			1.76	1.76
Run 2 – Injection 2 (Peak Start)	2.619				1.76
Run 2 – Injection 3 (Peak Start)	2.620				1.76
Run 2 – Injection 4 (Peak Start)	2.622				1.76
Run 1 – Injection 1 (Peak End)	23.784	23.778			5.42	5.42	5.42	0.00
Run 1 – Injection 2 (Peak End)	23.786				5.42
Run 1 – Injection 3 (Peak End)	23.803				5.42
Run 1 – Injection 4 (Peak End)	23.737				5.42
Run 2 – Injection 1 (Peak End)	23.709	23.669			5.42	5.42
Run 2 – Injection 2 (Peak End)	23.672				5.42
Run 2 – Injection 3 (Peak End)	23.633				5.42
Run 2 – Injection 4 (Peak End)	23.660				5.42

 

 

Table 4:          Calibration parameter obtained from first run

	Slope	x	Intercept
Log Pow =	2.712269	log k	+ 2.35367
R =	0.9983

 

 

Table 5:          Calibration parameter obtained from second run

	Slope	x	Intercept
Log Pow =	2.712720	log k	+ 2.355159
R =	0.9969

 

 

Table 6:          Values for determination of Pow, dead time and calibration graph obtained from 1st run

Name	Log Pow nominal	RT [min]	Mean RT [min]	SD [min]	log k	Log Powdetermined	Mean log Pow	SD log Pow
Test Item (Peak Start)	---	2.634	2.630	0.003	-0.214	1.77	1.77	0.00
		2.631			-0.215	1.77
		2.628			-0.217	1.77
		2.627			-0.217	1.77
Test Item (Peak End)	---	23.784	23.778	0.001	1.132	5.42	5.42	0.00
		23.786			1.132	5.42
		23.803			1.132	5.42
		23.737			1.131	5.42
Thiourea*	---	1.634	1.635	0.001	---	---	---	---	Dead time
		1.635
		1.635
		1.635
Nitrobenzene	1.9	2.912	2.911	0.001	-0.107	2.06	2.06	0.00	Reference Items
		2.910			-0.108	2.06
		2.912			-0.107	2.06
		2.911			-0.108	2.06
Atrazine	2.6	3.479	3.479	0.001	0.052	2.49	2.49	0.00
		3.479			0.052	2.49
		3.478			0.052	2.49
		3.480			0.052	2.49
Diphenylamine	3.4	5.459	5.458	0.001	0.369	3.35	3.35	0.00
		5.457			0.369	3.35
		5.458			0.369	3.35
		5.456			0.369	3.35
Benzylbenzoate	4.0	7.660	7.659	0.001	0.566	3.89	3.89	0.00
		7.660			0.566	3.89
		7.658			0.566	3.89
		7.658			0.566	3.89
Phenanthrene	4.5	12.574	12.569	0.005	0.825	4.59	4.59	0.00
		12.572			0.825	4.59
		12.563			0.825	4.59
		12.566			0.825	4.59
Fluoranthene	5.1	17.630	17.621	0.009	0.990	5.04	5.04	0.00
		17.627			0.990	5.04
		17.610			0.990	5.04
		17.616			0.990	5.04
Triphenylamine	5.7	31.364	31.355	0.022	1.260	5.77	5.77	0.00
		31.382			1.260	5.77
		31.333			1.259	5.77
		31.341			1.259	5.77

*Thiourea was used for determination of the dead time; RT = retention time; SD = standard deviation

 

 

Table 7:          Values for determination of Pow, dead time and calibration graph obtained from 2nd run

Name	Log Pow nominal	RT [min]	Mean RT [min]	SD [min]	log k	Log Pow determined	Mean log Pow	SD log Pow
Test Item (Peak Start)	---	2.626	2.622	0.003	-0.218	1.76	1.76	0.00
		2.619			-0.221	1.76
		2.620			-0.221	1.76
		2.622			-0.220	1.76
Test Item (Peak End)	---	23.709	23.669	0.032	1.130	5.42	5.42	0.00
		23.672			1.129	5.42
		23.633			1.129	5.42
		23.660			1.129	5.42
Thiourea*	---	1.636	1.636	0.001	---	---	---	---	Dead time
		1.636
		1.635
		1.635
Nitrobenzene	1.9	2.913	2.911	0.001	-0.108	2.06	2.06	0.00	Reference Items
		2.911			-0.108	2.06
		2.910			-0.109	2.06
		2.911			-0.108	2.06
Atrazine	2.6	3.479	3.478	0.001	0.052	2.50	2.50	0.01
		3.477			0.051	2.49
		3.477			0.051	2.49
		3.478			0.052	2.50
Diphenylamine	3.4	5.456	5.454	0.002	0.368	3.35	3.35	0.00
		5.456			0.368	3.35
		5.452			0.368	3.35
		5.453			0.368	3.35
Benzylbenzoate	4.0	7.656	7.655	0.002	0.566	3.89	3.89	0.00
		7.656			0.566	3.89
		7.653			0.566	3.89
		7.653			0.566	3.89
Phenanthrene	4.5	12.558	12.559	0.003	0.825	4.59	4.59	0.00
		12.563			0.825	4.59
		12.560			0.825	4.59
		12.555			0.824	4.59
Fluoranthene	5.1	17.598	17.600	0.005	0.989	5.04	5.04	0.00
		17.604			0.989	5.04
		17.603			0.989	5.04
		17.593			0.989	5.04
Triphenylamine	5.7	31.303	31.310	0.015	1.258	5.77	5.77	0.00
		31.319			1.259	5.77
		31.325			1.259	5.77
		31.291			1.258	5.77

*Thiourea was used for determination of the dead time; RT = retention time; SD = standard deviation

Conclusions:

The test item was determined to have a mean partition coefficient (Log Pow) of 1.77 - 5.42 at a mean temperature of 20 ± 1.0 °C.

Executive summary:

EU Method A.8. – The partition coefficient of the test item was determined using the HPLC method.  The procedure employed was designed to be compatible with Method A.8., partition coefficient, of Commission Regulation (EC) No 440/2008 of 30 May 2008.

Analysis was performed using a solid phase of long hydrocarbon chains chemically bound onto silica (Luna 5µ C18(2) 100A; 250 x 3.0 mm), with a mobile phase mixture of 75 % methanol and 25 % 0.01 M phosphate buffer (pH 7.03).  A PDA detector at 220 nm and 223 nm was used for the reference mixture and test item respectively.  Reference items were used to determine column dead time and regression coefficients.

For the test item a mean measured partition coefficient range of log Pow = 1.77 - 5.42, with an absolute deviation of ≤ 0.01 log units at 20 °C ± 1 °C, at pH 7.03 was determined.

Description of key information

Partition coefficient: Log Pow= 2.4 - 3.0 at 20.0°C ± 2.0 °C; EU Method A.8. (Estimation Method (Solubility Ratio)); C. Bär (2018)

Partition coefficient: Log Pow= 1.77 - 5.42 at 20.0°C ± 1.0 °C; EU Method A.8. (HPLC Method); C. Bär (2018)

Key value for chemical safety assessment

Log Kow (Log Pow):

3

at the temperature of:

20 °C

Additional information

EU Method A.8. – The partition coefficient of the test item was determined using the HPLC and calculation methods.  The procedures employed were designed to be compatible with Method A.8., partition coefficient, of Commission Regulation (EC) No 440/2008 of 30 May 2008.  As part of the wider testing programme it was determined experimentally that the test item is surface active (C. Bär, EU Method A.5. (2017)).  As per EU Method A.8., neither the shake-flask method nor the HPLC method is applicable to surface active substances.  Potentially misleading results may arise due to emulsification (flask method) or secondary column interactions (HPLC Method).  As such the HPLC Method should be regarded as supplementary information as part of a weight of evidence based on the calculation method.

HPLC Method:  Analysis was performed using a solid phase of long hydrocarbon chains chemically bound onto silica (Luna 5µ C18(2) 100A; 250 x 3.0 mm), with a mobile phase mixture of 75 % methanol and 25 % 0.01 M phosphate buffer (pH 7.03).  A PDA detector was used at 220 nm (reference solution), 223 nm (test item).  Reference items were used to determine column dead time and regression coefficients.

For the test item a measured partition coefficient of log Pow 1.77 - 5.42 was determined.

Estimation Method (Solubility Ratio):  An aliquot of test item (50.7 mg) was placed in a glass vessel, n-octanol was added in a stepwise manner.  After each addition of n-octanol, the vessel was shaken for at least 10 min.  The sample was then visually checked for undissolved test item.  If the test item was not dissolved further n-octanol was added in the manner previously described.  The test was performed at 20.8 ℃.

For the test item an estimated partition coefficient of log Pow = 2.4 - 3.0 at a temperature of 20 ± 2.0 °C was determined.