Disclosed is a method of separating organic or organometallic materials under supercritical fluid conditions, the method comprising the steps of providing a bed of packing material selected from a metal oxide/hydroxide support material having phsophorous-containing organic molecules bonded to reactive sites on said support material, alumina and alumina-containing mixtures. The materials are introduced to the bed and a fluid is added to the bed under supercritical fluid conditions. The fluid removes one of the materials from the bed.