Abstract: Subcritical water is formed from pure water under high temperature and high pressure. The change of hydrogen-bond network results in the obvious change of physical properties of water such as polarity and viscosity. Subcritical water chromatography (SubWC), as a method of high performance liquid chromatography which takes subcritical water as mobile phase, is one kind of novel separation technique developed recently. Common gas chromatographic or liquid chromatographic instrument modified properly can be used as the instrument for SubWC. Both packed columns used in liquid chromatography and capillary columns used in gas chromatography can be applied in SubWC. The selectivity can be adjusted by changing column temperature or pressure and addition of the organic modifiers or salts in mobile phase. Both flame ionization detector and ultraviolet detector can be used as the detecting part of SubWC. Thus the range of its application and selection of optimal conditions are largely broadened. Currently this novel separation mode is still in the stage of research and development and mostly used in the fast separation of samples with polar and medium polar. The characteristics of SubWC are illustrated from the aspects and design of instruments, the elution characteristics of mobile phase and the selection of stationary phase. Moreover, the recent development of SubWC is systematically reviewed.

Key words: mobile phase, review , stationary phase, subcritical water, liquid chromatography