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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 OECD 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))
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 (Dead time method)
The solutions of the test chemical and reference substances were prepared in acetonitrile. each of the reference substances and test chemical were analysed by HPLC.
The column was saturated with solvent (mobile phase) in isocratic mode on below chromatographic conditions. After 20 min of column saturation with mobile phase, sequential analysis of formamide (for dead time: t0), reference substances and test chemical was performed on HPLC. All the HPLC runs were performed in duplicates. Retention time tR was measured to calculate the capacity factors k
(mentioned in below equation no. 1), it was then converted in log to obtain log k. A standard curve between log k versus log Koc was plotted to obtain the value of log Koc of test chemical.

Equation no. 1
K= tR -t0/t0
where
k= capacity factor,
tR= retention time of test substance and reference substance.
t0=retention time of Urea.

Operating Conditions:
HPLC Model No. : Agilent Technologies,1260 Infinity
Data Acquisition software : ChemStationOpen lab Control Panel
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
Analytical monitoring:
not specified
Details on sampling:
- Concentrations: 400 mg/l
- Sampling interval: A test chemical solution was prepared by dissolving 4 mg of test chemical in acetonitrile to prepare 400 mg/L and filtered through 0.22 nm nylon syringe filter. pH of the resulting solution was 5.7.
Key result
Sample No.:
#1
Type:
log Koc
Value:
3.28 dimensionless
pH:
5.7
Temp.:
25 °C
Remarks on result:
other: logKoc was reported to be 3.280±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 3.280±0.001 at 25°C
Transformation products:
not specified

Table: Reference substance result.

Reference Substance

Tr1

Tr2

Mean S.D

K

Log K

Log Pow

Formamide

0.897

0.897

0.897±0.000

NA

NA

NA

2-Nitrobenzamide

1.084

1.085

1.085±0.001

0.209

-0.679

1.3

p-Toluamide

1.156

1.156

1.156±0.000

0.288

-0.539

1.5

Aniline

1.506

1.507

1.507±0.001

0.679

-0.167

2.1

2 - Nitrophenol

2.178

2.179

2.179±0.001

1.428

0.154

2.6

Benzamide

1.07

1.07

1.070±0.000

0.192

-0.714

1.4

Phenanthrene

11.798

11.694

11.746±0.074

12.094

1.08

3.7

 

 

Table: Result of test chemical.

Test substance

K

LogK

Log Koc

Mean of logKoc ± S.D

Tr1

5.610 

5.254 

0.721 

 3.279

 3.280 

± 0.001

Tr2

 5.617

5.262 

 0.721

 3.280

 

This table represents the mean log Koc and SD of test chemical.

 

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 3.280±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 chemical solution was prepared by dissolving 4 mg of test chemical in acetonitrile to prepare 400 mg/L and filtered through 0.22 nm nylon syringe filter. pH of the resulting solution was 5.7. 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.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 generalize calibration graph was prepared. Both were analyzed on HPLC considering the similar conditions. After analyzing on above conditions calibration curve of selected reference substances was prepared to obtain log Koc value. The reference substances were Formamide, 2-Nitrobenzamide, p-Toluamide , Aniline, 2 - Nitrophenol , Benzamide and Phenanthrene having Koc value ranging from 1.3 to 3.7. The Log Koc value of test chemical was determined to be 3.280±0.001 dimensionless at 25°C.This log Koc value indicates that the substance has a moderate sorption to soil and sediment and therefore have 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 (Experimental study report, 2019). The solutions of the test substance and reference substances were prepared in appropriate solvents. A test chemical solution was prepared by dissolving 4 mg of test chemical in acetonitrile to prepare 400 mg/L and filtered through 0.22 nm nylon syringe filter. pH of the resulting solution was 5.7. 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.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 generalize calibration graph was prepared. Both were analyzed on HPLC considering the similar conditions. After analyzing on above conditions calibration curve of selected reference substances was prepared to obtain log Koc value. The reference substances were Formamide, 2-Nitrobenzamide, p-Toluamide , Aniline, 2 - Nitrophenol , Benzamide and Phenanthrene having Koc value ranging from 1.3 to 3.7. The Log Koc value of test chemical was determined to be 3.280±0.001 dimensionless at 25°C.This log Koc value indicates that the substance has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:
1 905.46

Additional 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, 2019). The solutions of the test substance and reference substances were prepared in appropriate solvents. A test chemical solution was prepared by dissolving 4 mg of test chemical in acetonitrile to prepare 400 mg/L and filtered through 0.22 nm nylon syringe filter. pH of the resulting solution was 5.7. 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.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 generalize calibration graph was prepared. Both were analyzed on HPLC considering the similar conditions. After analyzing on above conditions calibration curve of selected reference substances was prepared to obtain log Koc value. The reference substances were Formamide, 2-Nitrobenzamide, p-Toluamide , Aniline, 2 - Nitrophenol , Benzamide and Phenanthrene having Koc value ranging from 1.3 to 3.7. The Log Koc value of test chemical was determined to be 3.280±0.001 dimensionless at 25°C.This log Koc value indicates that the substance has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.