Strategic approach for method selection in high-performance liquid chromatography

A strategic approach for the selection of high-performance liquid chromatographic methods in pharmaceutical analysis is outlined. Firstly, on the basis of the acid-base properties of the solute (s) and its hydrophobicity (as reflected by its log P value or total number of carbons), a battery of Chromatographic methods is selected. This battery of methods contains first choice, second choice and excluded methods. The Chromatographic modes considered are reversed-phase, normal-phase, gradient elution and ion-pair. Afterwards, on the basis of a structure-retention relationship, initial solvent strength conditions (i.e., the percentage of the organic modifier in the mobile phase) can be chosen in the reversed-phase and normal-phase mode corresponding to the chromatographersʹ needs.