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

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 January 2018 - 23 March 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Version / remarks:

Regulation (EC) 440/2008 of 30 May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

Version / remarks:

22 Jan 2001

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

25 °C ± 1 °C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus:
HPLC

- Type:
Agilent 1260 HPLC system

- Type, material and dimension of analytical (guard) column:
Column - EC 150/4.6 Nucleodur 100-5 CN-RP 150 x 4.6 mm; 5 µm. Guard column - None

- Detection system: PDA detector


MOBILE PHASES
- Type:
isocratic elution, 55 % eluent 1, 45 % eluent 2

Eluent 1 – Methanol
Eluent 2 – 0.01 M phosphate buffer (pH 7.03)

Phosphate buffer pH 7 (0.01 M) – 6.816g potassium dihydrogen phosphate was dissolved in approximately 0.5 L ultra-pure water. The pH value of the buffer solution was adjusted to a value of 7.00 by adding 30 mL of the sodium hydroxide (1 M) solution. The buffer was brought to a final volume of 1 L with ultra-pure water. 1.6 L ultra-pure water and 0.4 L of the buffer solution were mixed to yield a 0.01 M buffer solution. The pH value was 7.03.


- Experiments with additives carried out on separate columns:
not applicable

- pH:
7.03.

- Solutes for dissolving test and reference substances:
Methanol was used as diluent for the reference and test item solutions.


DETERMINATION OF DEAD TIME
- Method: by means of an inert substances which are not retained by the column

REFERENCE SUBSTANCES
- Identity (dead time determination): Sodium Nitrate (EC: 231-554-3)
- Identity (reference substances, Koc determination): Phenol (EC: 203-632-7), Isoproturon (EC: 251-835-4), Naphthalene (EC: 202-049-5), 1,2,3-Trichlorobenzene (EC: 201-757-1), Phenanthrene (EC: 201-581-5), 4.4'-DDT (EC: 200-024-3)


DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 2 µL injections of 103.7 mg/L of test item in methanol was introduced to the column
- Quantity of reference substances: Sodium Nitrate (71.68 mg/l), Phenol (19.85 mg/l), Isoproturon (61.20 mg/l), Naphthalene (3.55 mg/l), 1,2,3-Trichlorobenzene (44.16 mg/l), Phenanthrene (35.00 mg/l), 4.4'-DDT (246.96 mg/l)
- Intervals of calibration: Retention times of reference substances was determined over a 30 minute runtime duration. The following mean retention times were recorded arising from two calibration runs:
Calibration Run 1: Sodium nitrate (1.320 min), Phenol (2.612 min), Isoproturon (3.432 min), Naphthalene (5.024 min), 1,2,3-Trichlorobenzene (5.614 min), Phenanthrene (8.510 min), 4.4'-DDT (19.068 min)
Calibration Run 2: Sodium nitrate (1.313 min), Phenol (2.596 min), Isoproturon (3.403 min), Naphthalene (4.961 min), 1,2,3-Trichlorobenzene (5.534 min), Phenanthrene (8.355 min), 4.4'-DDT (18.561 min)


REPETITIONS
- Number of determinations: Eight repetitions in total, consisting of 4 injections per run over two runs.


EVALUATION
- Calculation of capacity factors k': The adsorption coefficient (KOC) is deduced from the capacity factor (k’) using a calibration plot of log k’ versus log KOC of the selected reference compounds. k' = (tR - t0)/t0. tR = HPLC retention time of test or reference item (minutes), t0 = HPLC dead time (minutes)
- Calculation of retention times: The reference mix was injected two times before and two times after the test item sample. The retention times were of these injections were measured directly.
- Determination of the log Koc value: The partition coefficient of the test item was obtained by interpolation from the calibration graph, using the calculated capacity factor.

Key result

Type:

log Koc

Remarks:

Mean value of Sample # 1 and # 2

Value:

<= 2.24 dimensionless

pH:

7.03

Temp.:

25 °C

Remarks on result:

other: Mean value

Remarks:

Mean of two runs

Sample No.:

#1

Type:

log Koc

Value:

<= 2.26 dimensionless

pH:

7.03

Temp.:

25 °C

Remarks on result:

other: Mean value

Remarks:

Mean value of four injections of test item.

Sample No.:

#2

Type:

log Koc

Value:

<= 2.21 dimensionless

pH:

7.03

Temp.:

25 °C

Remarks on result:

other: Mean value

Remarks:

Mean value of four injections of test item.

Details on results (HPLC method):

- Retention times of reference substances used for calibration:
See any other information on results incl. tables


- Details of fitted regression line (log k' vs. log Koc):
See any other information on results incl. tables


- Graph of regression line attached
See attached background material.


- Average retention data for test substance:
See any other information on results incl. tables

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 Koc 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 Koc of test item (mean of two runs)

	Retention Time [min]	Mean retention time [min]	Mean retention time of two runs [min]	Absolute deviation [min]	Log Koc	Mean log Koc	Mean log Koc of two runs	Absolute deviation of log Koc
First run – Injection 1 (Peak Start)	1.475	1.473	1.47	0.01	< 1.32*	< 1.32*	< 1.32*	not applicable
First run – Injection 2 (Peak Start)	1.461				< 1.32*
First run – Injection 3 (Peak Start)	1.463				< 1.32*
First run – Injection 4 (Peak Start)	1.491				< 1.32*
Second run – Injection 1 (Peak Start)	1.446	1.460			< 1.32*	< 1.32*
Second run – Injection 2 (Peak Start)	1.491				< 1.32*
Second run – Injection 3 (Peak Start)	1.432				< 1.32*
Second run – Injection 4 (Peak Start)	1.469				< 1.32*
First run – Injection 1 (Peak End)	3.850	3.838	3.79	0.10	2.27	2.26	2.24	0.05
First run – Injection 2 (Peak End)	3.844				2.27
First run – Injection 3 (Peak End)	3.768				2.21
First run – Injection 4 (Peak End)	3.891				2.30
Second run – Injection 1 (Peak End)	3.753	3.734			2.23	2.21
Second run – Injection 2 (Peak End)	3.731				2.21
Second run – Injection 3 (Peak End)	3.704				2.19
Second run – Injection 4 (Peak End)	3.749				2.22

 

 

Table 4:          Calibration parameter obtained from first run

	Slope		Intercept
Log k‘ =	0.255252	× log Koc	- 0.296923
R =	0.9967

 

 

Table 5:          Calibration parameter obtained from second run

	Slope		Intercept
Log k‘ =	0.253177	× log Koc	- 0.295251
R =	0.9966

 

 

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

Name	Log KOCnominal	Retention Time [min]	Mean retention time [min]	SD [min]	log k’	Log KOCdetermined	Mean log KOC	SD log KOC	Comment
Test item (peak start)	-	1.475	1.473	0.012	-0.930	< 1.32**	< 1.32**	not applicable
		1.461			-0.971	< 1.32**
		1.463			-0.965	< 1.32**
		1.491			-0.888	< 1.32**
Test item (peak end)	-	3.850	3.838	0.044	0.283	2.27	2.26	0.04
		3.844			0.282	2.27
		3.768			0.268	2.21
		3.891			0.290	2.30
Sodium nitrate*	-	1.322	1.320	0.001	-	-	-	-	Dead time
		1.320
		1.319
		1.320
Phenol	1.32	2.614	2.612	0.002	-0.009	1.13	1.13	0.00	Reference item
		2.612			-0.009	1.13
		2.612			-0.009	1.13
		2.608			-0.011	1.12
Isoproturon	1.86	3.435	3.432	0.004	0.205	1.97	1.97	0.01	Reference item
		3.432			0.204	1.96
		3.434			0.205	1.97
		3.425			0.203	1.96
Naphthalene	2.75	5.037	5.024	0.013	0.450	2.93	2.92	0.01	Reference item
		5.030			0.449	2.92
		5.027			0.448	2.92
		5.003			0.446	2.91
1,2,3-Trichlorobenzene	3.16	5.629	5.614	0.016	0.514	3.18	3.17	0.01	Reference item
		5.622			0.513	3.17
		5.615			0.512	3.17
		5.588			0.510	3.16
Phenanthrene	4.09	8.539	8.510	0.028	0.738	4.05	4.05	0.01	Reference item
		8.524			0.737	4.05
		8.510			0.736	4.05
		8.465			0.733	4.03
4.4'-DDT	5.63	19.157	19.068	0.088	1.131	5.59	5.58	0.01	Reference item
		19.134			1.130	5.59
		19.047			1.128	5.58
		18.932			1.125	5.57

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

**below determination limit of the method (log Koc = 1.5 according to OECD 121 and EC method C.19) and below the lowest used reference standard (log Koc of the lowest reference standard phenol is 1.32)

 

 

 

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

Name	Log KOCnominal	Retention Time [min]	Mean retention time [min]	SD [min]	log k’	Log KOCdetermined	Mean log KOC	SD log KOC	Comment
Test item (peak start)	-	1.446	1.460	0.026	-0.994	< 1.32**	< 1.32**	not applicable	-
		1.491			-0.868	< 1.32**
		1.432			-1.043	< 1.32**
		1.469			-0.925	< 1.32**
Test item (peak end)	-	3.753	3.734	0.022	0.269	2.23	2.21	0.02
		3.731			0.265	2.21
		3.704			0.260	2.19
		3.749			0.268	2.22
Sodium nitrate*	-	1.316	1.313	0.003	-	-	-	-	Dead time
		1.315
		1.313
		1.309
Phenol	1.32	2.602	2.596	0.007	-0.008	1.13	1.12	0.01	Reference item
		2.602			-0.008	1.13
		2.591			-0.012	1.12
		2.588			-0.013	1.11
Isoproturon	1.86	3.414	3.403	0.007	0.204	1.97	1.96	0.01	Reference item
		3.414			0.204	1.97
		3.394			0.200	1.96
		3.389			0.199	1.95
Naphthalene	2.75	4.987	4.961	0.026	0.447	2.93	2.92	0.01	Reference item
		4.980			0.446	2.93
		4.943			0.442	2.91
		4.934			0.441	2.91
1,2,3-Trichlorobenzene	3.16	5.567	5.534	0.034	0.511	3.18	3.17	0.01	Reference item
		5.559			0.510	3.18
		5.511			0.505	3.16
		5.499			0.504	3.16
Phenanthrene	4.09	8.421	8.355	0.063	0.733	4.06	4.05	0.01	Reference item
		8.395			0.732	4.06
		8.314			0.727	4.04
		8.289			0.725	4.03
4.4'-DDT	5.63	18.767	18.561	0.199	1.124	5.61	5.59	0.02	Reference item
		18.690			1.122	5.60
		18.434			1.115	5.57
		18.351			1.113	5.56

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

**below determination limit of the method (log Koc = 1.5 according to OECD 121 and EC method C.19) and below the lowest used reference standard (log Koc of the lowest reference standard phenol is 1.32)

Validity criteria fulfilled:

yes

Remarks:

The log Koc of two measurements were made under identical conditions, using the same set of reference items and fell within a range of ± 0.25 log units. The quality criteria requirements of OECD guideline 121 were fulfilled.

Conclusions:

The test item was determined to have a mean adsorption/desorption coefficient (Log Koc) of 3.36 at a mean temperature of 25 ± 1.0 °C and pH 7.03.

Executive summary:

EU Method C.19. –  The estimated Adsorption Coefficient (Koc) of the test item was determined using a procedure designed to be compatible with Method C.19., Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC), of Commission Regulation (EC) No 440/2008 of 30 May 2008.

Analysis was performed using a HPLC equipped with an analytical column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties.  A moderately polar stationary phase based on a silica matrix was used (EC 150/4.6 Nucleodur 100-5 CN-RP 150 x 4.6 mm; 5 µm).  A mobile phase of 55 % methanol to 45 % 0.01 M phosphate buffer (pH 7.03) was used and the column temperature was 25 °C ± 1 °C.  The log Koc was measured in duplicate under identical conditions and using the same set of reference items.  Both measurements fell within a range of ± 0.25 log units.

The estimated Adsorption Coefficient (Log Koc) of the test item was determined to be: < 2.24 ± 0.05 at pH 7.03 and 25 °C ± 1 °C

Description of key information

Adsorption coefficient: log K_OC < 2.24 ± 0.05 at pH 7.03 and 25 °C ± 1 °C; EU Method C.19.; C Bär (2017)

Key value for chemical safety assessment

Koc at 20 °C:

2.24

Additional information

EU Method C.19. –  The estimated Adsorption Coefficient (Koc) of the test item was determined using a procedure designed to be compatible with Method C.19., Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC), of Commission Regulation (EC) No 440/2008 of 30 May 2008.

Analysis was performed using a HPLC equipped with an analytical column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties.  A moderately polar stationary phase based on a silica matrix was used (EC 150/4.6 Nucleodur 100-5 CN-RP 150 x 4.6 mm; 5 µm).  A mobile phase of 55 % methanol to 45 % 0.01 M phosphate buffer (pH 7.03) was used and the column temperature was 25 °C ± 1 °C.  The log Koc was measured in duplicate under identical conditions and using the same set of reference items.  Both measurements fell within a range of ± 0.25 log units.

The estimated Adsorption Coefficient (Log Koc) of the test item was determined to be: < 2.24 ± 0.05 at pH 7.03 and 25 °C ± 1 °C