Fördelningskoefficienter

Fördelningskoefficienter, often referred to as partition coefficients or distribution coefficients, describe the ratio of the concentration of a substance in two immiscible phases at equilibrium. This ratio is a fundamental property that indicates how a solute will distribute itself between two phases, such as an organic solvent and water, or a liquid and a gas.

The partition coefficient is typically expressed as a logarithm, known as log P or log K_ow, where P stands for partition and ow refers to octanol-water. A higher log P value signifies that the substance is more soluble in the non-polar phase (e.g., octanol) than in the polar phase (e.g., water). Conversely, a lower log P indicates greater solubility in the polar phase.

These coefficients are crucial in various scientific fields. In pharmacology, they help predict how a drug will be absorbed, distributed, metabolized, and excreted within the body. In environmental science, partition coefficients are used to assess the potential for pollutants to accumulate in different environmental compartments like soil, water, and living organisms. They also play a role in chemical engineering for designing separation processes, such as liquid-liquid extraction. The value of a partition coefficient is temperature-dependent and can also be influenced by the pH of the system if the solute can ionize.