[No public or meaningful name is available]

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

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))

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

Column Temperature: 40 °C

Details on study design: HPLC method:

Chromatographic conditions:
- Column type: length: 250 mm, inner diameter: 4 mm
- Stationary Phase: LiChrospher 100 CN, particle diameter: 5 μm
- Mobile Phase: A: 832 ml demineralized water + 168 ml buffer pH 6* *buffer solution pH 6: Riedel-de Haёn, Art. No. 33545 LOT 72270 B: 1000 ml acetonitrile
- Flow rate: 1.5 ml/min, isocratic with 70 % A and 30 % B of the mobile phase
- Detection: UV, 210 nm
- Injection volume: 5 μl

- Calibration substances:
- Sodium nitrate
- 2-Nitrobenzamide
- 3,5-Dinitrobenzamide
- Triazoxide
- Naphthalene
- 1,2,3-Trichlorobenzene
- Phenanthrene

Details on sampling:

The test item and the calibration substances were dissolved in acetonitrile / demineralized water 1:1. The concentration for the calibration substances was ca. 0.06 to 0.4 mg/ml. The concentration for the test item was ca. 5.8 mg/ml.

Details on matrix:

Stationary Phase: LiChrospher 100 CN, particle diameter: 5 μm

Details on test conditions:

The pH of 6.3 was determined using a calibrated pH-meter with a single-rod glass electrode.

Type:

Koc

Value:

100

Temp.:

40 °C

Remarks on result:

other: at pH 6.3

Type:

log Koc

Value:

2

Temp.:

40 °C

Remarks on result:

other: at pH 6.3

Details on results (HPLC method):

Area - % weighted Log Koc for all peaks of the test item: Log Koc = 2 (100 area % of the test item).

Transformation products:

no

The log Koc of 2 was measured at an environmentally relevant pH-value of 6.3 and a calibration temperature of 40 °C.

Conclusions:

The log Koc of 2 was measured at an environmentally relevant pH-value of 6.3 and a calibration temperature of 40 °C.

Executive summary:

The adsorption coefficient (log Koc) of the test item is 2 at pH 6.3 estimated by OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC) (Currenta, 2009).

Description of key information

The measured KOC-value of the substance is 100 at pH 6.3 determined by OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC) (Currenta, 2009).

Key value for chemical safety assessment

Koc at 20 °C:

100

Additional information

The adsorption coefficient (Koc) of the substance was determined according to the HPLC method at 40 °C. In order to comply with the guideline OECD 121 and considering environmental relevance, pH 6 was chosen as pH value for the buffer. The reference Koc- values in the OECD-guideline presumably refer to 25 °C. Even though the column temperature was 40 °C, this temperature is without influence on the result of the determination. The calibration was done referring to Koc- values of reference substances determined at 25 °C. The HPLC chromatogram of the substance showed a resolved band of thirteen signals (main and minor components). No reference substance with a Koc- value below the value for the signal at RT = 1.6 min. (component 1) of the test item was available. For this reason the result for the signal of component 1 was extrapolated. Although the determined value does not exactly meet the range of application of the test guideline (1,3-5), we consider the value as valid (measurement uncertainty +/- 0,5 log units). For adsorption coefficient of the substance follows: Adsorption coefficient of all peaks of the substance determined by HPLC, calculated with area % and their correspondence Log Koc = 2.0 (100 area % of the test item).