NOVELTY - Analyzing trace amounts of oxygen in pure gas involves converting separated oxygen to a carbon oxide or oxides by passing the oxygen over carbon. The carbon oxides are converted to methane by mixing the carbon oxides with hydrogen in the presence of heated nickel catalyst. The methane is introduced into a flame ionization detector to determine the methane amount.    USE - For analyzing trace amounts of oxygen in pure gas (claimed).    ADVANTAGE - The inventive method provides easy detection of oxygen trace amount by using the gas chromatograph, which detects very low ppb oxygen gas, thus providing the gas industry analyze and prepare oxygen traces in the low ppb range.    DETAILED DESCRIPTION - Analyzing trace amounts of oxygen in pure gas involves separating the oxygen from a gas mixture. The separated oxygen gas is converted to a carbon oxide or oxides by passing the oxygen over carbon at an elevated temperature. The carbon oxides are converted to methane by mixing the carbon oxides with hydrogen in a presence of a heated nickel catalyst. The methane is introduced into a flame ionization detector (54) to determine the amount of methane. The amount of methane is compared with an amount of methane produced in a control sample of a gas mixture with a known amount of oxygen. An INDEPENDENT CLAIM is also included for a method for measuring ultra low trace amounts of oxygen in a gas mixture comprising:    (a) providing a gas chromatograph (10), a flame ionization detector, a mass of heated carbon and a heated nickel catalyst;    (b) introducing a gas mixture to be analyzed and a carrier gas (48) into the gas chromatograph to form a mixture of a gas mixture and carrier gas;    (c) passing the mix of the gas mixture and carrier gas through a column of a gas chromatograph to separate oxygen from the other gasses;    (d) passing the oxygen through the heated carbon at an elevated temperature to form carbon oxides;    (e) providing a mass of hydrogen gas;    (f) passing the carbon oxides over the heated nickel catalyst in the presence of hydrogen gas as to form methane; and    (g) introducing the methane into the flame ionization detector to provide an indication of the amount of oxygen in the original gas mixture.    DESCRIPTION OF DRAWING(S) - The figure is a schematic illustration of a device for analyzing trace amounts of oxygen.    Gas chromatograph (10)    Automatic sampling valve (42)    Carrier gas (48)    Flame ionization detector (54)    Hydrogen gas line (56)