Benzyl isovalerate

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 OECD Guideline

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:

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: 422.8 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 422.8 mg/l. The pH of test substance was 4.9.

Key result

Sample No.:

#1

Type:

log Koc

Value:

2.025 dimensionless

pH:

4.9

Temp.:

25 °C

Remarks on result:

other: Log Koc value reported as 2.025± 0.000

Details on results (HPLC method):

The Adsorption coefficient (KOC) on soil and on sewage sludge of the test chemical was determined to be 2.025± 0.000 at 25°C.

Transformation products:

not specified

Test substance		K	LogK	Log Koc by Generalized Calibration Graph	Mean of Log Koc ± S.D.
tR1	1.336	0.506	-0.296	2.025	2.025 ± 0.000
tR2	1.336	0.506	-0.296	2.025

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 2.025± 0.000 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 422.8 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 functional similarity with the test substance and calibration graph prepared. The reference substances were Benzoic acid methylester, Xylene, Ethylbenzene, Toluene, Naphthalene, Benzoic acid phenylester having Koc value ranging from 1.8 to 2.87. The Log Koc value of test chemical was determined to be 2.025 ± 0.000 at 25°C. This log Koc value indicates that the substance 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. 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 422.8 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 functional similarity with the test substance and calibration graph prepared. The reference substances were Benzoic acid methylester, Xylene, Ethylbenzene, Toluene, Naphthalene, Benzoic acid phenylester having Koc value ranging from 1.8 to 2.87. The Log Koc value of test chemical was determined to be 2.025 ± 0.000 at 25°C. This log Koc value indicates that the substance 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:

105.925

Additional information

Experimental study for the test chemical and supporting study for its structurally and functionally similar read across substance were reviewed for the adsorption end point which are summarized as below:

 

In an experimental key study from study report (2018), 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 422.8 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 functional similarity with the test substance and calibration graph prepared. The reference substances were Benzoic acid methylester, Xylene, Ethylbenzene, Toluene, Naphthalene, Benzoic acid phenylester having Koc value ranging from 1.8 to 2.87. The Log Koc value of test chemical was determined to be 2.025 ± 0.000 at 25°C. This log Koc value indicates that the substance has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

In another study the adsorption coefficient (Koc) of test substance was determined to be 180 using a log Kow of 1.96 and a regression-derived equation (authoritative database, 2017). This Koc value suggests that test substance is expected to have moderate mobility in soil.

 

On the basis of above overall results for test chemical (from experimental study report) and for its read across substance from authoritative database (2017), it can be concluded that the log Koc value of test substance was determined to be 2.025, indicating that the test chemical has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.