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Physical & Chemical properties

Partition coefficient

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Description of key information

The log Kow of MV 31 was determined to be 5.1 at 23°C.

Key value for chemical safety assessment

Additional information

The n-Octanol/Water Partition Coefficient (log Kow) of MV 31 was conducted in 2013 according to U.S EPA guidance document OPPTS 830.7550 "Partition Coefficient (n-Octanol/Water), Shake Flask Method". Duplicate samples of MV 31 were prepared in each of the three octanol/water ratios (1:1, 1:2, and 2:1) and allowed for partitioning. The aqueous and n-octanol phases were carefully removed and analyzed for MV 31 separately using GC/MS. The log Kow of MV 31 was determined to be 5.1 at 23°C for all n-octanol/water ratios, with an overall RSD of 0.40%. The study was a guideline study conducted under GLP compliance with no deviation. Therefore, it is considered reliable without restrictions and a key study.

A previous study was conducted in 2001 following the OECD 117 HPLC method. The test system used seven calibration substances with known log Kow of 1.3 - 3.7. The measured retention time for the calibration substance ranged from 1.752 to 2.838 minutes. MV 31 had a measured retention time of 9.18 minute, resulted in extrapolated log Kow of 6.15. However, the test system had poor regression correlation coefficient (0.7658) from the reference substance, and the retention time of the test substance is significant higher than the retention time of the highest calibration point, the log Kow of MV 31 was reported as ≥ 3.7, the highest calibration substance. This study is considered as reliable with acceptable restriction and can be used as a supporting study.