Abstract: Chromatographically active stationary phases and adsorbents are made from sol-gels produced by the hydrolysis and condensation of alkoxysilanes that contain hydrolyzable alkoxy groups and non-hydrolyzable organo groups. The organo groups provide chromatographic activity in the resulting hybrid organic-inorganic material. Deposited as hybrid sol-gel coatings on solid supports, the coatings are heated to activate them. Hybrid organic-inorganic materials which contain different organic groups distributed in an inorganic network may be designed for the improved analysis of specific groups of compounds by the selection of the organo groups. Hydrocarbon mixtures may be advantageously analyzed by such hybrid materials.