Reaction mass of 2-{[2-(2-hydroxyethoxy)ethoxy]carbonyl}benzoic acid and 2,2'-oxydiethanol

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:

2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

In order to ensure a stable performance of the HPLC column, the column temperature was set to 40°C. The reference Koc-values in the OECD guideline presumably refer to 25°C.

Details on study design: HPLC method:

HPLC-METHOD PARAMETERS:
- Equipment: HPLC, Agilent 1100
- Column: LiChrospher 100 CN, 250 mm length, 4 mm internal diameter, 5 μm particle size
- Eluent A: 832 ml water + 168 ml buffer pH = 6
- Eluent B: acetonitrile
- Solvent program: Isocratic 80 % A and 20 % B
- Flow: 1 ml/min
- Column temperature:40 °C
- Injection volume: 5 μl
- Detector: UV, 210 nm

PREPARATION OF TEST SOLUTIONS:
Calibration substances and also the solution of sodium nitrate, prepared for the determination of the dead time:
- dissolved in acetonitrile/water 9:1
- concentration of the calibration substances after dilution with acetonitrile to measuring concentration approx. 0.03 to 0.11 mg/ml and 0.10 mg/ml for the solution of sodium nitrate
The test item:
- dissolved in acetonitrile
- concentration of the test item approx. 1.43 mg/ml


pH DETERMINATION OF THE AQUEOUS PART OF THE MOBILE PHASE:
- was done with a pH meter equipped with a calibrated single-rod glass electrode, result: pH 6.3

Type:

log Koc

Value:

<= -0.7

Temp.:

25 °C

Remarks on result:

other: 100 area % of the test item

Details on results (HPLC method):

Even though the column temperature was 40°C, this temperature has no influence on the result of the determination. Therefore the Koc -value of the test item determined within this study also refers to 25 °C

Validity criteria fulfilled:

not specified

Conclusions:

An adsorption coefficient (log Koc) of <= -0.7 was determined at pH 6. The result can be expected to be equal at 25 °C. The value is corresponding to the area weighed logKoc for all peaks of the test item.

Executive summary:

For the test item the adsorption coefficient was estimated by the HPLC-method according to OECD TG 121. The test was performed at pH 6 (environmental relevant). An adsorption coefficient (log Koc) of <= -0.7 was determined. Even though the column temperature was 40°C, this temperature has no influence on the result of the determination. Therefore the logKoc-value of the test item determined within this study also refers to 25 °C.

Description of key information

An adsorption coefficient (log Koc) was estimated to be <= -0.7 at pH 6.  The value is corresponding to the area weighed logKoc for all peaks of the test item (Garcia-Sanchez, 2012).

Key value for chemical safety assessment

Koc at 20 °C:

0.2

Additional information

Even though the column temperature was 40°C, this temperature has no influence on the result of the determination. Therefore the logKoc-values of the test item determined within this study also refers to 20 °C.

Log KOC = -0.7 may not be entered as Key value. Therefore, -0.7 was calculated as KOC = 0.1995