The n-octanol/water partition coefficient (Pow) is one of the most important parameters employed for estimating a chemical’s environmental fate and toxicity. The shake-flask method, one direct experimental method, is prone to experimental artifacts for highly hydrophobic compounds. Thus, a valid method for direct determination of the Pow of highly hydrophobic compounds is needed. The slow-stirring method has been demonstrated to provide reliable log Pow data to log Pow greater than 5. This study was performed to evaluate the accuracy of slow-stirring experiment for determination of log Pow, particularly for highly hydrophobic compounds. 1, 2, 3, 4-tetrachlorobenzene, hexachlorobenzene, 2, 2′, 3, 3′, 5, 5′, 6, 6′-octachlorobiphenyl, decachlorobiphenyl, and p, p′-DDT(4.5＜log Pow＜8.2) were tested. The octanol/water partiton coefficient of those chemicals were 4.71±0.02, 5.41±0.06, 7.26±0.04, 7.87±0.10, and 6.03±0.06, respectively. The octanol/water partition coefficient by the slow-stirring method were very similar to the literature values. These results indicate that the slow-stirring method allows for reliable determination of log Pow of highly hydrophobic chemicals.
PDF Links
Full text via DOI 
Download Citation 
