This method is for determining the composition of refinery gas streams or vaporized liquefied petroleum gas (LPG) using a preconfigured, commercially available gas chromatograph. At a minimum, the following components are reported: non-condensable gases, individual C1 through C4 hydrocarbons and C5 paraffins. C5 olefins and C6+ hydrocarbons are reported as a composite. Some configurations of the analyzer will separate the C5 olefins and certain C6+ hydrocarbons. Oxygen is not separated from argon. Results for hydrogen sulfide, if present, may not be quantitative on some analyzers. The lower limit of quantitation for each component or composite is 0.05 mol-%. If the measurement of lower concentrations of hydrocarbons are needed, use UOP Method 899, race Hydrocarbons in Hydrogen, Hydrocarbon Gases, or LPG by GC.?LPG samples may be analyzed by UOP Method 373, omposition of C2 through C5 Hydrocarbon Mixtures by GC,?or UOP Method 980, 5 and Lower Boiling Dienes, Olefins, and Paraffins in Naphthas by GC.?Alternatively, LPG samples may be expanded to the gas phase and run by this method.