Recent work on the mechanism of solute-phase interactions is discussed and used to explain the mechanism of distribution between the mobile and stationary phases. Examples of solute-solvent-stationary phase interactions are considered for silica gel, non-polar bonded phases and ion-pair chromatography. The use of silica gel for exclusion chromatography is also described in conjunction with the preparation of very high efficiency liquid-chromatographic columns and the trend towards compatible low dead volume detectors. A practical liquid chromatograph-mass spectrometer system is described in detail and results from commercially available liquid chromatograph-mass spectrometer equipment are given. The automation of liquid-chromatographic analysis involving automatic injection devices and computer data acquisition is discussed and the precision that can be obtained from such equipment given. Finally, an example of the use of high precision as an alternative to resolution in a liquid-chromatographic separation is demonstrated.