[2-(1-ethoxyethoxy)ethyl]benzene

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 February 2017 - 12 July 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Version / remarks:

2008

Deviations:

no

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))

Version / remarks:

2001

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil

Radiolabelling:

no

Test temperature:

Column temperature: 35°C ± 1°C

Details on study design: HPLC method:

CALCULATION OF PKA
-Perrin calculation method (pKalc 5.0, module in Pallas 3.0, CompuDrug International, USA) for the logarithm range of 1 - 14.
-Result: pKa acidic: none; pKa basic: none.

HPLC CONDITIONS
-Apparatus: Acquity UPLC system (Waters)
-Column: Acquity UPLC HSS Cyano, 100 mm x 2.1 mm i.d., dp = 1.8 µm (Waters)
-Injection volume: 5 µL
-Detector: Acquity UPLC TUV (Waters)
-UV detection: 210 nm

MOBILE PHASE
-Type: unbuffered mobile phase
-Composition: 55/45 (v/v) methanol/water
-Flow: 0.4 mL/min

DETERMINATION OF DEAD TIME
- Method: by inert substance which is not retained by the column
- A solution of formamide was prepared in 55/45 (v/v) methanol/water from a stock solution (5 g/L) in methanol.

REFERENCE SUBSTANCES
- Identity: Acetanilide, Monuron, 2,5-Dichloroaniline, Naphthalene, Benzoic acid phenylester, Fenthion, Phenanthrene and 4,4’-DDT.
- Solutions of the reference substances were prepared in 55/45 (v/v) methanol/water from stock solutions (ca. 1 g/L) in methanol.

TEST ITEM
A 10.0 mg/L test item solution in 55/45 (v/v) methanol/water was prepared from a stock solution (1 g/L) in methanol.

DETERMINATION OF RETENTION TIMES
- Duplicate injections of the unretained substance, reference substances and test item.
- Single injection of the blank (55/45 (v/v) methanol/water).

DATA HANDLING
- Dead time (t0) = mean retention time of the unretained substance
- Calculation of capacity factor k' of each compound from its retention time : k' = (tr-t0)/t0
- Log k’ values (references substances) were plotted against their known log Koc values using linear regression analysis (least squares method).
- Log Koc of the substance was calculated by substituting its mean log k’ in the regression line (log k' vs log Koc).

Key result

Type:

log Koc

Value:

2.5 dimensionless

Remarks on result:

other: unbuffered mobile phase

Key result

Type:

Koc

Value:

290 L/kg

Remarks on result:

other: unbuffered mobile phase

Details on results (HPLC method):

- Retention times of reference substances used for calibration: see table below
- Details of fitted regression line (log k' vs. log Koc): log k’ = 0.331 log Koc– 0.795 (r=0.98, n=16)
- Graph of regression line attached (see illustration below)
- The chromatogram of the test item showed one substance peak
- Average retention data for the test item: see table below
- The value of log Koc obtained from duplicate measurements was within ± 0.25 log units.

Table: Results Adsorption coefficient (HPLC estimation method)

 

Substance	Retention time [min]			log Koc	Koc
	RT1	RT2	mean
Formamide (t0)	0.777	0.771	0.774
Acetanilide	1.056	1.045	1.051	1.26
Monuron	1.326	1.311	1.319	1.99
2,5-Dichloroaniline	1.533	1.514	1.524	2.55
Naphthalene	1.803	1.780	1.792	2.75
Benzoic acid phenylester	2.167	2.136	2.152	2.87
Fenthion	3.001	2.949	2.975	3.31
Phenanthrene	3.329	3.277	3.303	4.09
4,4’-DDT	8.820	8.628	8.724	5.63
Test item	1.590	1.584	1.587	2.5	2.9E02

Remark: the log Koc values of the reference substances are given in OECD 121 and are based on soil adsorption data.

Conclusions:

The log Koc of the substance at neutral pH was estimated to be 2.5 (Koc= 290).

Executive summary:

The Koc was measured with the adsorption-desorption HPLC estimation method in accordance with OECD 121 and in compliance with GLP. The unbuffered mobile phase was 55/45 (v/v) methanol/water and the wavelength of detection 210 nm. The stationary phase contained cyanopropyl chains chemically bonded to silica. Formamide was used as unretained substance. Eight reference substances were used with known log Koc values in the range of 1.26 to 5.63. Duplicate injections of unretained substance, reference substances and test item were applied. Both chromatograms of the substance solution (10 mg/L) showed one test substance peak. The corresponding log Koc value was calculated from the regression line (log k' vs log Koc) to be 2.5 (Koc= 290).

Description of key information

Log Koc = 2.5 (EC C.19 and OECD 121: HPLC estimation method)

Key value for chemical safety assessment

Koc at 20 °C:

290

Additional information

The Koc was measured with the adsorption-desorption HPLC estimation method in accordance with OECD 121 and in compliance with GLP. The unbuffered mobile phase was 55/45 (v/v) methanol/water and the wavelength of detection 210 nm. The stationary phase contained cyanopropyl chains chemically bonded to silica. Formamide was used as unretained substance. Eight reference substances were used with known log Koc values in the range of 1.26 to 5.63. Duplicate injections of unretained substance, reference substances and test item were applied. Both chromatograms of the substance solution (10 mg/L) showed one test substance peak. The corresponding log Koc value was calculated from the regression line (log k' vs log Koc) to be 2.5 (Koc= 290).

[LogKoc: 2.5]