octadecylsilane (ODS) - the most popular reversed phase in HPLC. Octadecylsilane phases are bonded to silica or polymeric packings. Both monomeric and polymeric phases are available.

See also silica based bonded phases.

overload - in preparative chromatography, the overload condition is defined as the mass of sample injection onto the column at which efficiency and resolution begin to be affected if the sample size is further increased. See sample capacity.

packing - material contained inside the column; responsible for the separation. A dence bed of small (3 of 5 Ám) totally porous particles, providing high surface for adsorption of the analyte molecules.

particle size (dp) - the average particle size of the packing in an LC column. A 5-um column would be packed with particles having definite particle size distribution; packings are never monodisperse.

See also particle size.