SEPARATION MEDIA AND APPARATUS

The invention provides improved separation media for use in chromatography and electrophoresis, or for the selective absorption of certain components of a sample mixture, especially in a preliminary stage of an analysis. Improved media according to the invention comprises first particles capable or retaining one or more of the components of a sample mixture and second particles selected to have a higher thermal conductivity than the first particles, so that the thermal conductivity of the media is higher than that of media comprising the first particles alone. The media may be incorporated in packed or capillary columns for chromatography (especially nanoflow HPLC) or for capillary electrophoresis, or may be coated on a substrate. Particular embodiments of the media may comprise mixtures of first particles comprising siliceous polymers, second particles of gold, diamond or graphite. Chromatographic columns and apparatus incorporating them are also disclosed.