Gas chromatography is a method of analytical separation techniques used to analyze volatile substances in the gas phase. In gas chromatography, the components of a sample are dissolved in a solvent and vaporized in order to separate the analytes by distributing the sample between two phases: a stationary phase and a mobile phase. The mobile phase (or "moving phase") is a carrier gas, usually an inert gas such as helium, nitrogen, argon, carbon dioxide, hydrogen and air. Gas chromatography is one of the sole forms of chromatography that does not utilize the mobile phase for interacting with the analyte.
Gas chromatography is a widely used technique across most industries: for quality control in the manufacture of many products from cars to chemicals to pharmaceuticals; for research purposes from the analysis of meteorites to natural products; and for safety from environmental to food to forensics.