A chemistry technique; a type of column chromatography, used to separate the components of a mixed substance. The substance is held stationary by an inert solid coated with an inert liquid which is not likely to evaporate (i.e. is nonvolatile), while a gas (called an eluant) flows past it bringing out the components one at a time.

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.