The Measurement of Partition Coefficients

Abstract

Abstract Partition coefficient (P) is a widely‐measured property, yet there is considerable variation among published log P values. This paper examines the factors that can affect the measurement of partition coefficient, and makes recommendations as to good practice. Accuracy of partition coefficient determination can be affected by temperature, lack of mutual phase saturation, pH, buffer type and concentration, phase miscibility, solute concentration, solute and solvent purity, solute stability, phase volume ratio, solute adsorption and failure to reach equilibrium conditions. It is recommended that partitioning be carried out at constant temperature using either a stirred flask technique or the filter probe.