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Physical & Chemical properties

Partition coefficient

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Description of key information

The partition coefficient (Pow) of the calcium salt of the target substance in n-Octanol/Water was determined to be 0.0006 ± 0.0001 (95 % confidence interval) which corresponds to log Pow of -3.25 ± 0.083 (95 % confidence interval) using the shake flask method. The test substance is a multi-constituent substance, but due to technical reasons only the partition coefficient of one component could be determined. Only one clean peak was determined, therefore, only one log Pow value can be stated.

Key value for chemical safety assessment

Log Kow (Log Pow):
-3.25
at the temperature of:
20 °C

Additional information

The partition coefficient endpoint of the target substance was addressed with a read-across to the source substance - a calcium salt of the target substance. As the organic components of both substances are the same, and the partition coefficient is relevant only for organic substances, the inorganic cations don't play a role on the partition coefficient, therefore, the read-across approach was considered acceptable.

A study was conducted in accordance with OECD TG 107, Regulation (EC) No 440/2008 method A.8 and OPPTS 830.7550 to determine the partition coefficient of the source test item using the shake flask method. A stock solution of the source test item was prepared in n-octanol presaturated with water. This sample was sonicated for 20 minutes. The saturated solution was centrifuged at 20 °C (5 min, 4000 rpm). A volume of 20 mL of the sample was shaken with 4 mL Acetonitrile : Water = 1 : 9 (v/v). The phases were separated by centrifugation (4000 rpm, 5 min, 20 °C) and the aqueous phase was diluted with Acetonitrile : Water = 1 : 9 (v/v) for HPLC analysis.Test vessels with octanol/water mixture in different ratios were shaken for 5 minutes by hand. Separation of the two phases was achieved by centrifugation at 20 °C (5 min, 4000 rpm). Then the two phases were analysed using HPLC. The partition coefficient Pow of the test item was determined to be 0.0006 and the log Pow was -3.25, respectively.The test substance is a multi-constituent substance, but due to technical reasons only the partition coefficient of one component could be determined. Only one clean peak was determined, therefore, only one log Pow value can be stated.