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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:
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:
To determine Adsorption coefficient (KOC) on soil and on sewage sludge of the test chemical using HPLC.
GLP compliance:
no
Type of method:
HPLC estimation method
Media:
soil/sewage sludge
Radiolabelling:
not specified
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
Details on sampling:
- Concentrations: 400 mg/l
- Sampling interval: A test item solution was prepared by accurately weighing 4 mg of test item and diluted with Acetonitrile up to 10 ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 4.9.
Key result
Sample No.:
#1
Type:
log Koc
Value:
1.967 dimensionless
pH:
4.9
Temp.:
25 °C
Remarks on result:
other: logKoc was reported to be 1.967 ± 0.001
Details on results (HPLC method):
The Adsorption coefficient (KOC) on soil and on sewage sludge of the test chemical was determined to be 1.967 ± 0.001 at 25°C
Transformation products:
not specified

Test substance

K

LogK

Log Koc

by Generalized Calibration

Graph

Mean of Log Koc ± S.D.

tR1

 1.418

0.599

-0.223

1.966

1.967±0.001

tR2

1.420

0.601

-0 .221

1.968

Validity criteria fulfilled:
yes
Conclusions:
The Adsorption Coefficient of test chemical was determined as per the HPLC method (OECD Guideline-121). The Log Koc value was determined to be 1.967 ± 0.001 at 25°C.
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 weighing 4 mg of test item and diluted with Acetonitrile up to 10 ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 4.9. 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 were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were 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-naphtol, Direct Red 81, Benzoic acid methylester, Carbendazim, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, Phenol, N,Ndimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene, DDT, having Koc value ranging from 1.25 to 5.63. The Log Koc value of test chemical was determined to be 1.967 ± 0.001 at 25°C. This log Koc value indicates that the test chemical has a low sorption to soil and sediment and therefore have 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 (Experimental study report, 2018). The solutions of the test substance and reference substances were prepared in appropriate solvents. A test item solution was prepared by accurately weighing 4 mg of test item and diluted with Acetonitrile up to 10 ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 4.9. 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 were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were 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-naphtol, Direct Red 81, Benzoic acid methylester, Carbendazim, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, Phenol, N,Ndimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene, DDT, having Koc value ranging from 1.25 to 5.63. The Log Koc value of test chemical was determined to be 1.967 ± 0.001 at 25°C. This log Koc value indicates that the test chemical has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:
92.682

Additional information

Various experimental key and supporting studies of the test chemical were reviewed for the adsorption end point which are summarized as below:

 

In an experimental key study from study report (2018), 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 weighing 4 mg of test item and diluted with Acetonitrile up to 10 ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 4.9. 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 were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were 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-naphtol, Direct Red 81, Benzoic acid methylester, Carbendazim, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, Phenol, N,Ndimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene, DDT, having Koc value ranging from 1.25 to 5.63. The Log Koc value of test chemical was determined to be 1.967 ± 0.001 at 25°C. This log Koc value indicates that the test chemical has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

In a supporting study from authoritative database (2017), adsorption experiment was conducted for estimating the adsorption coefficient (Koc) value of test chemical. The adsorption coefficient (Koc) value was calculated using a logKow of 1.83 and a regression derived equation. The adsorption coefficient (Koc) value of test chemical was estimated to be 240 (Log Koc = 2.38). This Koc value indicates that the test chemical has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

In aprediction done using theKOCWIN Programof Estimation Programs Interface was used to predict the soil adsorption coefficient i.e Koc value of test chemical. The Soil Adsorption Coefficient i.e. Koc value of test chemical was estimated to be 25.71 L/kg (log Koc= 1.4101) by means of MCI method at 25 deg. C. This log Koc value indicates that test chemical has negligible sorption to soil and therefore have rapid migration potential to ground water.

 

On the basis of above overall results for test chemical (from study report, authoritative and modelling database), it can be concluded that the log Koc value of test chemical was estimated to be ranges from 1.4101 to 2.38, respectively, indicating that the test chemicalhas a negligible to low sorption to soil and sediment and therefore have rapid to moderate migration potential to ground water.