Title: octanol-water partition ratio
Long Title: IUPAC Gold Book - octanol-water partition ratio
DOI: 10.1351/goldbook.08192
Status: current

Definition
Equilibrium concentration of a substance in octan-1-ol divided by its equilibrium concentration in water.

Note
This is a measure of the lipophilicity of a substance. It is used in pharmacological studies and in the assessment of environmental fate and transport of organic chemicals.

Source
- PAC, 2022, 94, 353. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021)' on page 474 (https://doi.org/10.1515/pac-2018-1010)

Other Outputs
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- json: https://goldbook.iupac.org/terms/view/08192/json
- xml: https://goldbook.iupac.org/terms/view/08192/xml

Citation: Citation: 'octanol-water partition ratio' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.08192
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Accessed: 2026-05-10T12:04:36+00:00