Thermodynamically Correct Bioavailability Estimations.
Final rept. 1 May 91-31 Oct 95,
CINCINNATI UNIV OH DEPT OF CHEMISTRY
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The goal of this research is to develop thermodynamically correct bioavailability estimations using chromatographic stationary phases as a model of the interphase, system. It has been previously established that octanol-water partition coefficients are not thermodynamically relevant for the modeling of bioaccumulation processes Opperhuizen et al., Environ. Sci. Technol. 1988, 22, 286. They investigated the thermodynamic properties of the partitioning of chlorobenzenes between fish lipids and water, and showed that bioconcentration is accompanied by positive enthalpy and entropy changes. In contrast, the partitioning df these compounds between octanol and water is accompanied by negative enthalpy and by small negative or positive entropy changes. They conclude that the difference in the thermodynamic properties of these processes arise from the different structures of fish lipids and octanol, and that only under very specific condition and only for structurally similar compounds can a relationship between octanol-water partitioning and bioaccumulation be expected.
- Physical Chemistry