N,N-diethylaniline

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guidelines

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))

Principles of method if other than guideline:

Adsorption coefficient of test chemical was determined by using HPLC method.

GLP compliance:

no

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

25°C

Details on study design: HPLC method:

HPLC Procedure:
The solutions of the test substance and reference substances were prepared in solvent mentioned in 4.3. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(table 3).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor.

Operating Conditions:
HPLC Model No. : Agilent Technologies,1260 Infinity
Flow Rate : 1.0ml/min
Column : ZORBAX Eclipse Plus C18, 4.6×100mm, 3.5 μm
Mobile phase : ACN : water (55:45)
Temperature : 25°C
Detector : Diode Array Detector @210nm
Injector : Autosampler
Injector volume : 10μl
Data Acquisition software : ChemStationOpen lab Control Panel

Analytical monitoring:

not specified

Key result

Sample No.:

#1

Type:

log Koc

Value:

3.424 dimensionless

Temp.:

25 °C

Remarks on result:

other: other details not specified

Details on results (HPLC method):

The Adsorption coefficient (KOC) on soil and on sewage sludge of the test chemical was determined to be 3.424 at 25°C

Transformation products:

not specified

Table1 :

Reference substance	Log Koc	Rt1	Rt2	Rt3	Mean Rt ± S.D.	k	Log k
Urea	NA	0.887	0.887	0.888	0.887±0.001	0	0
Acetanilide	1.25	1.265	1.267	NA	1.266±0.001	0.4273	-0.3693
4-chloroaniline	1.96	2.012	2.021	NA	2.0165±0.006	1.2734	0.105
4-methylaniline(p-Tolouidine)	1.9	1.755	1.748	NA	1.7515±0.005	0.9746	-0.0112
N-methylaniline	2.28	2.303	2.294	NA	2.2985±0.006	1.5913	0.2018
p-toluamide	1.78	1.18	1.182	NA	1.181±0.001	0.3315	-0.4796
Aniline	2.07	1.513	1.495	NA	1.504±0.013	0.6956	-0.1576
2,5-Dichloroaniline	2.58	3.548	3.574	NA	3.561±0.018	3.0147	0.4792
4-nitrophenol	2.46	1.559	1.56	NA	1.5595±0.001	0.7582	-0.1202
2-nitrophenol	2.47	2.213	2.224	NA	2.2185±0.008	1.5011	0.1764
2-nitrobenzamide	1.45	1.091	1.094	NA	1.0925±0.002	0.2317	-0.6351
3-nitrobenzamide	1.95	1.159	1.158	NA	1.1585±0.001	0.3061	-0.5142
Nitrobenzene	2.35	2.426	2.429	NA	2.4275±0.002	1.7368	0.2397
4-Nitrobenzamide	1.93	1.161	1.159	NA	1.16±0.001	0.3078	-0.5118
1-naphthylamine	3.51	2.389	2.393	NA	2.391±0.003	1.6956	0.2293
1-naphthol	3.3	2.41	2.403	NA	2.4065±0.005	1.7131	0.2338
DirectRed81	3.43	0.827	0.818	NA	0.8225±0.006	-0.0727	1.139
Benzoicacidmethylester	1.8	2.585	2.61	NA	2.5975±0.018	0.1917	-0.7175
Carbendazim	2.35	1.193	1.193	NA	1.193±0.000	0.345	-0.4622
Benzoicacidphenylester	2.87	6.57	6.642	NA	6.606±0.051	6.4476	0.8094
Xylene	2.58	6.241	6.232	NA	6.2365±0.006	6.031	0.7804
Ethylbenzene	2.649	6.359	6.355	NA	6.357±0.003	6.1669	0.7901
Toluene	2.369	4.378	4.382	NA	4.38±0.003	3.938	0.5953
Naphthalene	2.75	6.127	6.218	NA	6.1725±0.064	5.9589	0.7752
1,2,3-trichlorobenzene	3.16	9.519	9.541	NA	9.53±0.016	9.7441	0.9887
Pentachlorophenol	3.695	8.282	8.259	NA	8.2705±0.016	8.3241	0.9203
Phenol	1.32	1.455	1.455	NA	1.455±0.000	0.6404	-0.1936
N,Ndimethylbenzamide	1.52	1.287	1.288	NA	1.2875±0.001	0.4515	-0.3453
3,5-dinitrobenzamide	2.31	1.308	1.311	NA	1.3095±0.002	0.4763	-0.3221
N-methylbenzamide	1.3	1.175	1.174	NA	1.1745±0.001	0.3241	-0.4893
Benzamide	1.26	1.092	1.092	NA	1.092±0.000	0.2311	-0.6362
phenanthrene	4.09	11.996	11.779	NA	11.8875±0.153	12.4019	1.0935
DDT	5.63	61.125	59.008	NA	60.0665±1.497	66.7187	1.8242

Table 2

Test substance		K	Log k	Log Koc by Generalized Calibration Graph	Mean of Log Koc ± S.D.
Rt1	8.899	9.033	0.956	3.424	3.424 ± 0.000
Rt2	8.890	9.023	0.955	3.424

Validity criteria fulfilled:

yes

Conclusions:

The Adsorption Coefficient of test substance was determined as per the HPLC method (OECD Guideline-121). The Log Koc value was determined to be 3.424 at 25°C. Thus based on the result it is concluded that the test substance has a moderate sorption to soil and sediment and therefore has slow migration potential to ground water.

Executive summary:

The adsorption coefficient Koc in soil and in sewage sludge of test chemical was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The solutions of the test substance and reference substances were prepared in appropriate solvents. A test item solution was prepared by accurately pipetting 4 microlitre of test item and diluted with Acetonitrile upto 10 ml. Thus, the test solution concentration was 375.2 mg/l(calculated according to its density). The pH of test substance was 6.4. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(Annex - 2).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances Acetanilide, 4-chloroaniline, 4-methylaniline(p-Tolouidine), N-methylaniline, p-toluamide, Aniline, 2,5-Dichloroaniline, 4-nitrophenol, 2 - nitrophenol, 2-nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4-Nitrobenzamide, 1-naphthylamine, 1-naphthol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, Phenol, N,N-dimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene, DDT were chosen having Koc value range from 1.25 to 5.63.

The Log Koc value of test chemical was determined to be 3.424 ± 0.000 dimensionless at 25°C.This log Koc value indicates that the substance has a moderate sorption to soil and sediment and therefore has slow migration potential to ground water.

Description of key information

The adsorption coefficient Koc in soil and in sewage sludge of test chemical was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The solutions of the test substance and reference substances were prepared in appropriate solvents. A test item solution was prepared by accurately pipetting 4 microlitre of test item and diluted with Acetonitrile upto 10 ml. Thus, the test solution concentration was 375.2 mg/l(calculated according to its density). The pH of test substance was 6.4. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(Annex - 2).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances Acetanilide, 4-chloroaniline, 4-methylaniline(p-Tolouidine), N-methylaniline, p-toluamide, Aniline, 2,5-Dichloroaniline, 4-nitrophenol, 2 - nitrophenol, 2-nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4-Nitrobenzamide, 1 -naphthylamine, 1-naphthol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, Phenol, N,N-dimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene, DDT were chosen having Koc value range from 1.25 to 5.63.The Log Koc value of test chemical was determined to be 3.424 ± 0.000 dimensionless at 25°C.This log Koc value indicates that the substance has a moderate sorption to soil and sediment and therefore has slow migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:

2 654.6

Additional information

Various experimental studies have been reviewed for test chemical for Adsorption endpoint and their results are summarized below.

The first study was reviewed from experimental study report in this report the adsorption coefficient Koc in soil and in sewage sludge of test chemical was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The solutions of the test substance and reference substances were prepared in appropriate solvents. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(Annex - 2).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances Acetanilide, 4-chloroaniline, 4-methylaniline(p-Tolouidine), N-methylaniline, p-toluamide, Aniline, 2,5-Dichloroaniline, 4-nitrophenol, 2 - nitrophenol, 2-nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4-Nitrobenzamide, 1-naphthylamine, 1-naphthol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, Phenol, N,N-dimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene, DDT were chosen having Koc value range from 1.25 to 5.63. The Log Koc value of test chemical was determined to be 3.424 ± 0.000 dimensionless at 25°C.This log Koc value indicates that the substance has a moderate sorption to soil and sediment and therefore has slow migration potential to ground water.

Next study reviewed from journal Chemosphere (1997) in this study an experimental was performed to determine adsorption coefficient o test chemical by using two different sludges from lab simulation in this study the test chemical solution is added to the sludge in centrifuge tubes and shaken. Thereafter the solution is centrifuged and the remaining concentration in the supernatant is measured.

The following modifications were made for sewage sludges:

1. 0.2 g dried sewage sludges were used for 50 ml test solution

2. for fresh sludges about 0.2 g (dry weight) were used in each test vessel

3. in addition to test solutions containing a 0.01 M CaC12 concentration, solutions of different water hardnesses were prepared by solving the desired concentrations of CaC12 in the test solution.

The log Koc value of test chemical was determined to be 1.68 and 1.76 dimensionless in two different sludges from lab simulation plant by using HPLC method. By considering log Koc value it is concluded that test chemical has low sorption to sludge and moderate migration potential to ground water.

 

Next study was reviewed from Ecotoxicology and Environmental Safety journal (1980) in this study the Koc value of test chemical was estimated by using equation taken from Kenaga and Goring (1978). The Koc value of test chemical was estimated to be 120 dimensionless (log Koc=2.079). By considering this log Koc value it is concluded that test chemical has low sorption to soil and sediment and therefore has moderate migration potential to ground water.

Last study was reviewed from authoritative database (HSDB, 2017) in this study the Koc value of test chemical was estimated by using a log Kow of 3.31and a regression-derived equation. The Koc of test chemical was estimated to be 1500 dimensionless log Koc= 3.1760. By considering this log Koc value of test chemical it is concluded that test chemical has moderate sorption to soil and sediments and therefore has slow migration potential to ground water.

By considering results of all the studies mentioned above it is concluded log Koc value of test chemical is in range of 1.68 – 3.4 dimensionless. This range log Koc value indicates that the substance has a low to moderate sorption to soil and sediment and therefore has moderate to slow migration potential to ground water.