Registration Dossier

Environmental fate & pathways

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

An adsorption coefficient (log Koc) in the range of 1.5 to 6.1 was determined at pH 6. The Area % weighted log Koc for all peaks of the test item was determined to be 5.2 (Neuland, 2013).

Key value for chemical safety assessment

Koc at 20 °C:
158 489

Additional information

"Should read: LogKoc at 25 °C"

For the substance the adsorption coefficient was determined by the HPLC-method according to OECD TG 121. Based upon its pKa, the substance exists mainly in its ionic form. For ionisable substances,two tests should be performed with both ionised and non-ionised form; the nonionic form exists at pH values > 11. A determination of the log Koc value by HPLC method at strong basic conditions is technically not feasible. Therefore, the test was performed at pH 6.

Even though the column temperature was 40°C, this temperature has no influence on the result of the determination. The calibration was done referring to Koc-values of reference substances determined at 25°C. Thus, the logKoc-values of the substance also refer to 25 °C. An adsorption coefficient (log Koc) in the range of 1.5 to 6.1 was determined.

The HPLC-chromatogram of the substance showed a mixture of 7 partially resolved peaks corresponding to 7 fractions. No calibration substance with a Koc-value above the value for the peaks 6 and 7 of the substance was available. For this reason the results for these peaks were extrapolated, and taken into account for calculation of the average log Koc value. The Area % weighted log Koc for all peaks of the test item was determined to be 5.2.

[LogKoc: 5.2]