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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:
1.857 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 1.8568 dimensionless at 25°C
Transformation products:
not specified

 

 Table: 1

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

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±0.005

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-naphtol

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

2.5975±0.051

1.9284

0.2852

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,N-dimethylbenzamide

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

phenantrene;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

Acetanilide

1.25

1.265

1.267

NA

1.266±0.001

0.4273

-0.3693

 

 

Table 2

Test substance

 

K

Log k

Log Koc

by Generalized Calibration

Graph

 

Mean of Log Koc ± S.D.

 

Rt1

1.317

0.4847

-0.3144

1.8568

 

1.8568±0.000

 

Rt2

 

1.317

0.4847

-0.3144

1.8568

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 1.8568 dimensionless at 25°C. Thus based on the result it is concluded that the test substance has a low sorption to soil and sediment and therefore has moderate 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. 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 substance 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-naphtol, 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, phenantrene;phenanthrene, DDT, Acetanilide were chosen having Koc value range from 1.239 to 4.09.

The Log Koc value of test chemical was determined to be 1.8568 dimensionless at 25°C.This log Koc value indicates that the substance has a low sorption to soil and sediment and therefore has moderate 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. 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 substance 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-naphtol, 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, phenantrene;phenanthrene, DDT, Acetanilide were chosen having Koc value range from 1.239 to 4.09.

The Log Koc value of test chemical was determined to be 1.8568 dimensionless at 25°C.This log Koc value indicates that the substance has a low sorption to soil and sediment and therefore has moderate migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:
1.857

Additional information

Different experimental studies have been reviewed from study report and peer reviewed journal for adsorption endpoint and their results are summarized below.

 

In first study 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 substance 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-naphtol, 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, phenantrene;phenanthrene, DDT, Acetanilide were chosen having Koc value range from 1.239 to 4.09.

The Log Koc value of test chemical was determined to be 1.8568 dimensionless at 25°C.This log Koc value indicates that the substance has a low sorption to soil and sediment and therefore has moderate migration potential to ground water.

 

Another study was reviewed from publication from Colloid & Polymer Science journal in this study the Adsorption experiment was performed in that the apparent adsorption rate was obtained by 200 ml of test chemical solution of 200 mg. dm -3 was stirred at a high rate of 500 rpm, and 0.20 g of the adsorbent was added. Samples were taken out and filtered using 0.45 Fan membrane-filters immediately. The residual concentration of the filtrate was determined by a total organic carbon analyzer. After analyzing The test chemical adsorbed only 5 % in 30 min on montmorillonite-Na clay. On the basis of this it is concluded that test chemical showed low sorption on montmorillonite-Na clay. The apparent adsorption rate was obtained by 200 ml of test chemical solution of 200 mg. dm -3 was stirred at a high rate of 500 rpm, and 0.20 g of the adsorbent was added. Samples were taken out and filtered using 0.45 Fan membrane-filters immediately. The residual concentration of the filtrate was determined by a total organic carbon analyzer. After analyzing The test chemical adsorbed only 5 % in 30 min on montmorillonite-Na clay. On the basis of this it is concluded that test chemical showed low sorption on montmorillonite-Na clay.

 

Last study was reviewed from environmental science technology journal (1987) in this study the adsorption desorption experiment was performed to determine adsorption capacity of test chemical on sediments EPA 5 and EPA 14 the sediments were obtained from the Environmental Research Laboratory, Athens, GA . Adsorption isotherms were determined by batch equilibration. The dry sediments were equilibrated with 0.01 M CaSO4, for 5 days at 4 oC before they were used in sorption experiments. The wet sediment was weighed into 25-mL glass centrifuge tubes and 25-mL aliquots of the sorbate solutions were pipetted into the centrifuge tubes containing the sediment.The sorption tubes were rotated end-over-end for approximately 16 h in a thermostated box at 25 oC,then samples were Centrifuged for 1 hour at 10000 rpm and 25 oC. After that Differential refractometry was used to analyze the supernatant solutions of the test chemical. Langmuir Parameters and percent desorption were calculated. Adsorption capacity of test chemical on sediment EPA 5 and EPA 14 was 11.1 mg/g and 5.9 mg/g respectively. On the basis of these values it is concluded that test chemical has low sorption to soil.

 

 By considering results of all the studies mentioned above it is concluded that test chemical has low sorption potential to soil and sediment therefore has moderate migration potential to ground water.