Abstract: Inorganic and organic impurities are removed from a metallocene catalyst compound comprising the steps of (a) separating inorganic impurities from said compound by forming a solution of said compound in an organic solvent medium which is substantially a non-solvent for said inorganic impurities, (b) treating the solution of said compound with a particulate absorbing material so as to absorb and remove organic impurities from said solution, and (c) separating the solid material, including said particulate absorbing material, from said solution. Optionally, water can be removed by adding a drying agent.