21. :something worth looking up for each will be the Partition coefficient , which will give you an idea of relative polarities. 22. Subtle differences in a compound's partition coefficient result in differential retention on the stationary phase and thus changing the separation. 23. The partition coefficient ( Log P ) is a measure of differential solubility of a compound in a hydrophilic solvent ( water ). 24. If one of the solvents is a gas and the other a liquid, a gas / liquid partition coefficient can be determined. 25. For example, the blood / gas partition coefficient of a general anesthetic measures how easily the anesthetic passes from gas to blood. 26. The hydrophobic effect can be quantified by measuring the partition coefficients of non-polar molecules between water and non-polar solvents. 27. The "'partition coefficient "'is the ratio of concentrations of un-ionized compound between the two solutions. 28. The concentration in aqueous phase is now 5.6 * 10 ^-5 M and the new partition coefficient is 22. 29. For nonionic organic contaminants, the K OC can be determined based on the octanol-water partition coefficient ( K OW ). 30. Used widely in pharmaceutical research, LogD is the logarithm of the " true " partition coefficient of a compound between octanol and water.