Method of removing metal carbonyls from a gaseous stream comprising contacting the metal carbonyl containing gaseous stream at elevated temperature with a particulate sorbent comprising modified copper aluminum spinel, wherein the copper aluminium spinel has been modified by a thermal treatment in a reducing atmosphere and a particulate sorbent for use in a method comprising a copper aluminium spinel being modified by thermal treatment in a reducing atmosphere at a temperature of between 250 and 500° C.