Abstract
Covers a method based on the selection of a gas chromatography column allowing the separation of the impurities to be determined. A gaseous test portion is passed through this column and the peaks obtained are detected by flame ionization and compared with those derived from an external standard. Uses two types of columns, one for the determination of methane, ethane and acetylene (adsorption chromatography) and the other for the determination of the other impurities (gas/liquid partition chromatography).