Quaternary ammonium compounds, N,N,N'-tris(hydroxyethyl)-N,N'-dimethyl-N'-C16-18 (even numbered) and C18 unsatd., alkyltrimethylenedi-, bis(Me sulfates) (salts)

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:

From November 16, 2017 to November 29, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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))

Deviations:

no

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))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Key result

Sample No.:

#1

Type:

log Koc

Value:

< 1.32 dimensionless

Temp.:

25 °C

Results:

Referencesubstances:

Measurement data: Retention times (RT) reference substances

Compound	RT1	RT2	RT3	RT4	RT5	RT6
	min.	min.	min.	min.	min.	min.
Sodium nitrate	1.015	1.017	1.017	1.053	1.040	1.042
Phenole	2.879	2.879	2.877	2.877	2.877	2.877
Methylbenzoate	3.247	3.245	3.242	3.240	3.242	3.240
Naphthaline	5.075	5.070	5.060	5.060	5.064	5.064
1,2,3-Trichlorbenzene	6.194	6.184	6.167	6.165	6.169	6.169
Phenanthrene	9.130	9.107	9.085	9.090	9.102	9.107
4,4’-DDT	24.185	24.035	23.955	23.978	24.042	24.069

 

Calculated values: The capacity factors k’ were calculated from the retention times using the equatio. The values are given in the following table.

Mean retention times (RT), capacity factors reference substances

Compound	RT Mean	RT Standard Deviation	RT Relative Standard Deviation	k’
	min.	min.	%
Sodium nitrate	1.031	0.016	1.598	0.0000
Phenole	2.877	0.001	0.032	1.7917
Methylbenzoate	3.243	0.003	0.086	2.1461
Naphthaline	5.065	0.006	0.120	3.9147
1,2,3-Trichlorbenzene	6.174	0.012	0.187	4.9906
Phenanthrene	9.103	0.016	0.174	7.8326
4,4’-DDT	24.044	0.081	0.337	22.3286

 

  

log K_OC/ log k’

The log K_OCvalues of the reference substances were taken from the guideline. The values for log k’ and log K_OCof the reference substances are presented in the following table:

Log k’ and log K_OCof reference substances

Compound	log k’	log KOC
Phenole	0.2533	1.32
Methylbenzoate	0.3317	1.80
Naphthaline	0.5927	2.75
1,2,3-Trichlorbenzene	0.6981	3.16
Phenanthrene	0.8939	4.09
4,4’-DDT	1.3489	5.63

 

Correlation results

Dead time is 1.031 ± 0.016 minutes, with a RSD of 1.598%.

The RSD of the retention times of the reference substances lay all below 1% except for sodium nitrate (RSD of retention times 1.598%).

Equation of the regression:

log k’ = 0.2546 * logK_OC– 0.1091
with a coefficient of determination r² = 0.9962

 

Test substance

Measurement data: Retention times (RT) test substance

Measurement	RT 1	RT 2	RT 3
	min.	min.	min.
Measurement 1	1.715	1.805	2.097
Measurement 2	1.737	1.827	2.100
Measurement 3	1.767	1.922	2.097
Mean	1.740	1.851	2.098
Standard Deviation	0.026	0.062	0.002

 

 

Peak areas test substance

Measurement	Area Peak 1	Relative Area Peak 1	Area Peak 2	Relative Area Peak 2
	mAU*min	%	mAU*min	%
Measurement 1	0.5345	85.53	0.0616	9.86
Measurement 2	0.6010	88.60	0.0520	7.67
Measurement 3	0.6211	90.97	0.0369	5.41
Mean	0.586	88.37	0.050	7.64
Relative Standard Deviation	7.7%	3.1%	24.8%	29.1%
Measurement	Area Peak 3	Relative Area Peak 3
	mAU*min	%
Measurement 1	0.0288	4.61
Measurement 2	0.0253	3.73
Measurement 3	0.0248	3.63
Mean	0.026	3.99
Relative Standard Deviation	8.3%	13.5%

As peak 3 showed a relative area < 5%, this peak was considered as minor peak.

 

Calculated values:The calculated values are presented in the following table:

Capacity Factor, log capacity factor, log K_OCtest substance

Peak 1 Test Substance	k’	log k’	log KOC
Measurement 1	0.6640	-0.1779	-0.270
Measurement 2	0.6852	-0.1642	-0.216
Measurement 3	0.7143	-0.1461	-0.145
Mean			-0.210
Standard deviation			0.062

 

 

Peak 2 Test Substance	k’	log k’	log KOC
Measurement 1	0.7513	-0.1242	-0.059
Measurement 2	0.7725	-0.1121	-0.012
Measurement 3	0.8647	-0.0632	0.181
Mean			0.037
Standard deviation			0.127

 

Peak 3 Test Substance	k’	log k’	log KOC
Measurement 1	1.0343	0.0146	0.486
Measurement 2	1.0377	0.0161	0.492
Measurement 3	1.0344	0.0147	0.487
Mean			0.488
Standard deviation			0.003

log K_OCwas calculated from the capacity factor as follows:

log K_OC= (log k’ + 0.1091) / 0.2546

 

Result and validity:

As peak 3 showed a relative area < 5 %, this peak was considered as minor peak. Although area is not necessarily correlated to absolute concentration if a UV detector is used, it is assumed that the test substance consists mainly of the peaks 1 and 2. All peaks of the test substance solution lay after sodium nitrate, used for the determination of the dead time, and before the first reference substance phenol. Using the correlation log k’ / log K_OC, the log K_OCof the peaks of the test substance was calculated as -0.210 – 0.037 (peak 1 and 2). Due to the fact that the calculated log K_OCof the test substance lay outside the calibrated range (1.32 – 5.63), the log K_OCof the test substance is stated as < 1.32.

  

Validity criteria and Results

Peak	Parameter	Criterion	Found	Assessment
1	Range (Max – Min. log KOC)	< 0.25	0.125	valid
	Value within Range of Reference Substances	1.32 - 5.63	-0.210	not valid*
2	Range (Max – Min. log KOC)	< 0.25	0.240	valid
	Value within Range of Reference Substances	1.32 - 5.63	0.037	not valid*
3	Range (Max – Min. log KOC)	< 0.25	0.006	valid
	Value within Range of Reference Substances	1.32 - 5.63	0.488	not valid*

* The calculated log K_OCof the test substance peaks lay outside the calibrated range (1.32 – 5.63), because the peaks eluted in the dead time of the method.

 

 

Validity criteria fulfilled:

yes

Conclusions:

Under study conditions, the log Koc value of the test substance for soil and sewage sluge was determined to be <1.32 at 25 ± 0.5˚C.

Executive summary:

A study was conducted to determine the adsorption coefficient (log Koc) of the substance on soil and on sewage sludge according to OECD Guideline 121, in compliance with GLP. In the study, measured HPLC retention data were obtained for 7 reference substances (i.e., sodium nitrate, phenol, methylbenzoate, naphthalene, 1,2,3-Trichlorobenzene,  phenanthrene and 4,4' DDT). A solvent blank followed by three injections of a solution of the reference substances were analysed with HPLC; then three injections of a solution of the test substance; and finally three injections of the solution with the reference substances, in total ten runs. For each reference substance, the capacity factor k’ was calculated from the retention time of sodium nitrate and the retention time of the respective reference substance. A calibration function was set up using the literature values for Koc of the reference substances and the mean capacity factor of the six determinations. In the graph log k’ versus log Koc, linear regression was performed, resulting in r²= 0.9962. The chromatogram of the test substance gave 1 large and 2 small peaks after sodium nitrate, used for the determination of the dead time, and before the first reference substance phenol. As peak 3 showed a relative area < 5 %, this peak was considered as minor peak. Although area is not necessarily correlated to absolute concentration if a UV detector is used, it is assumed that the test substance consists mainly of the peaks 1 and 2. Using the correlation log k’ / log Koc, the log Kocof the peaks of the test substance was calculated as -0.210 – 0.037 (peak 1 and 2). Due to the fact that the calculated log Koc of the test substance lay outside the calibrated range ( log Koc :1.32 – 5.63), the log Koc of the test substance was determined to be <1.32. Under study conditions, the log Koc of the test substance, for soil and sewage sludge was determined to be <1.32 at 25 ± 0.5˚C (Brinkmann, 2018).

Key value for chemical safety assessment

Koc at 20 °C:

20.89

Additional information

A study was conducted to determine the adsorption coefficient (log Koc) of the substance on soil and on sewage sludge according to OECD Guideline 121, in compliance with GLP. In the study, measured HPLC retention data were obtained for 7 reference substances (i.e., sodium nitrate, phenol, methylbenzoate, naphthalene, 1,2,3-Trichlorobenzene,  phenanthrene and 4,4' DDT). A solvent blank followed by three injections of a solution of the reference substances were analysed with HPLC; then three injections of a solution of the test substance; and finally three injections of the solution with the reference substances, in total ten runs. For each reference substance, the capacity factor k’ was calculated from the retention time of sodium nitrate and the retention time of the respective reference substance. A calibration function was set up using the literature values for Koc of the reference substances and the mean capacity factor of the six determinations. In the graph log k’ versus log Koc, linear regression was performed, resulting in r²= 0.9962. The chromatogram of the test substance gave 1 large and 2 small peaks after sodium nitrate, used for the determination of the dead time, and before the first reference substance phenol. As peak 3 showed a relative area < 5 %, this peak was considered as minor peak. Although area is not necessarily correlated to absolute concentration if a UV detector is used, it is assumed that the test substance consists mainly of the peaks 1 and 2. Using the correlation log k’ / log Koc, the log Koc of the peaks of the test substance was calculated as -0.210 – 0.037 (peak 1 and 2). Due to the fact that the calculated log Koc of the test substance lay outside the calibrated range ( log Koc :1.32 – 5.63), the log Koc of the test substance was determined to be <1.32. Under study conditions, the log Koc of the test substance, for soil and sewage sludge was determined to be <1.32 at 25 ± 0.5˚C (Brinkmann, 2018).