Ethyl formate

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 result using the OECD recommended 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:

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 : 20μl
Data Acquisition software : ChemStationOpen lab Control Panel

Analytical monitoring:

not specified

Details on sampling:

- Concentrations: 500 mg/l
- Sampling interval: A test item solution was prepared by accurately weighing 50mg of test item and diluted with mobile phase up to 100ml. Thus, the test solution concentration was 500mg/l. The pH of test substance was 4.61.

Key result

Type:

log Koc

Value:

1.963 dimensionless

pH:

4.61

Temp.:

25 °C

Remarks on result:

other: Log Koc value reported as 1.963 ± 0.000

Details on results (HPLC method):

The Log Koc of test chemical was determined to be 1.963 ± 0.000 at 25°C.

Transformation products:

not specified

Reference substance	Log Koc	tR1	tR2	tR3	MeantR± S.D.	k	Log k
Urea	-	0.887	0.887	0.888	0.887±0.001	-	-
2 nitrobenzamide	1.45	1.091	1.094	-	1.092±0.002	0.231	-0.635
p toluamide	1.78	1.18	1.182	-	1.181±0.001	0.331	-0.479
aniline	2.07	1.513	1.495	-	1.504±0.013	0.695	-0.157
n methyl aniline	2.28	2.303	2.294	-	2.298±0.006	1.591	0.201
nitrobenzene	2.35	2.426	2.429	-	2.4275±0.002	1.736	0.239
2 nitro phenol	2.47	2.213	2.224	-	2.2185±0.008	1.501	0.176
2,5 dichloroaniline	2.58	3.548	3.574	-	3.561±0.018	3.014	0.479

Test substance		K	LogK	Log Koc by Generalized Calibration Graph	Mean of Log Koc ± S.D.
tR1	1.434	0.617	-0.210	1.963	1.963 ± 0.000
tR2	1.434	0.617	-0.210	1.963

Validity criteria fulfilled:

not specified

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 1.963 ± 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 50mg of test item and diluted with mobile phase up to 100ml. Thus, the test solution concentration was 500mg/l. The pH of test substance was 4.61. 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 structural similarity with the test substance and calibration graph was prepared. The reference substances were2 Nitrobenzamide, p Toluamide, aniline, n methyl aniline, nitrobenzene, 2 nitro phenol and 2,5 Dichloroanilinehaving Koc value ranging from 1.45 to 2.58.The Log Koc value of test chemical was determined to be 1.963 ± 0.000 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, 2016). The solutions of the test substance and reference substances were prepared in appropriate solvents. A test item solution was prepared by accurately weighing 50mg of test item and diluted with mobile phase up to 100ml. Thus, the test solution concentration was 500mg/l. The pH of test substance was 4.61. 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 structural similarity with the test substance and calibration graph was prepared. The reference substances were2 Nitrobenzamide, p Toluamide, aniline, n methyl aniline, nitrobenzene, 2 nitro phenol and 2,5 Dichloroanilinehaving Koc value ranging from 1.45 to 2.58.The Log Koc value of test chemical was determined to be 1.963 ± 0.000 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:

91.833

Additional information

Various experimental 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 (2016), 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 50mg of test item and diluted with mobile phase up to 100ml. Thus, the test solution concentration was 500mg/l. The pH of test substance was 4.61. 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 structural similarity with the test substance and calibration graph was prepared. The reference substances were2 Nitrobenzamide, p Toluamide, aniline, n methyl aniline, nitrobenzene, 2 nitro phenol and 2,5 Dichloroanilinehaving Koc value ranging from 1.45 to 2.58.The Log Koc value of test chemical was determined to be 1.963 ± 0.000 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.

 

Another adsorption study in soil was conducted for estimating the adsorption coefficient (Koc) value of test chemical (from handbook, 1999). The adsorption coefficient (Koc) value of test chemical was calculated to be 32 (Log Koc = 1.5051). 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 a supporting study from authoritative database (2018), adsorption experiment was conducted for estimating the adsorption coefficient (Koc) value of test chemical. The adsorption coefficient (Koc) value was calculated using a water solubility of 88.25 g/l & a regression derived equation and from molecular structure. The adsorption coefficient (Koc) value of test chemical was estimated to be 8 (Log Koc = 0. 903) and 4 (Log Koc = 0. 602), respectively. This Koc value indicates that the test chemical has a negligible sorption tosoil and sediment and therefore have rapid migration potential to ground water.

 

On the basis of above overall results for test chemical (from study report, handbook and authoritative databases), it can be concluded that the logKoc value of test chemicalranges from0.602–1.963indicating that the test chemicalhas a negligible to lowsorption to soil and sediment and therefore have rapid to moderate migration potential to ground water.