1904 8 299 It is well known that nitrogen distils off faster from liquid air than does oxygen, and that an oxygen-rich mixture is left behind.
1986 J. M. Dillard i. 8 Atmosphere oxygen-rich, Captain, slightly more than Terran standard.
1995 7 Jan. 73/3 Catalase and superoxide dismutase are biochemical policemen. Their role is to mop up two oxygen-rich substances—hydrogen peroxide and superoxide.