The method specified applies to the quantitative determination of hydrocarbons in liquefied petroleum gas, excluding components whose concentrations are below O,1 % (m/m). It is applicable to the analysis of propane, butane and their commercial mixtures which may include saturated and unsaturated C₂, C₃, C₄ and C₅ hydrocarbons. It does not apply to "on-line" chromatography.