A mode of chromatography carried out with a polar stationary phase and a nonpolar mobile phase. Adsorption on silica gel using hexane as a mobile phase would be a typical normal-phase system. Also prefers to the use of polar bonded phases, such as CN or NH2. Sometimes referred to as straight-phase chromatography.

A mode of chromatography performed when the stationary phase is more polar than the mobile phase. A typical normal-phase system would be adsorption chromatography on silica gel or alumina using mixtures of less polar eluents such as hexane–diethethyl ether as a mobile phase. Also refers to the use of polar bonded phases such as cyano and alumina. Sometimes called straight-phase chromatography.