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Environmental fate & pathways

Adsorption / desorption

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Description of key information

Experimental evaluation of the test substance's adsorption/desorption properties was not possible.  Therefore, an estimated value was of 32 to 551 L/kg was obtained using KOWWIN, version 1.67. 

Key value for chemical safety assessment

Koc at 20 °C:
551

Additional information

The QSAR calculation for the chemical class of non-hydrophobic is shown below:

Log10 Koc = 0.52 x Log10 Pow + 1.02 = 1.62 (Koc=42)

where: Koc, = adsorption coefficient;

Pow = partition coefficient (log10 Pow = 1.16, measured).

The QSAR calculation for Koc based on the log Pow method is based on the following equation:

Log10 Koc = 0.55 log10 Pow + correction factor = 0.59 (Koc= 3.9)

where, the measured value for the log Pow reported by Featherstone and Rutland (2010) was used, along with a correction factor of -0.0432 to account for the nitrogen groups on a non-fused aromatic ring (KOWWIN, version 1.67, Copyright 2000 U.S.A.).

No determination of the adsorption coefficient was possible by the HPLC estimation method, Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001. This method is invalid for the test material because the dissociation constant of the two primary amine functional groups was predicted to be 6.0 and 8.9, respectively. Therefore, the test material would maintain at least a single cationic charge over the entire environmentally relevant pH range of 5.5 to 7.5 applicable for the method. Cationic species have been demonstrated to interact with the HPLC column stationary phase by mechanisms other than partitioning, thus invalidating the estimation of the adsorption coefficient of the test material by comparison to the capacity factors of reference substances of known adsorption coefficient values.