Gas-liquid chromatography (GLC), or simply gas chromatography (GC), is a common type of chromatography used in organic chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture (the relative amounts of such components can also be determined). In some situations, GC may help in identifying a compound. In microscale chemistry, GC can be used to prepare pure compounds from a mixture.

Gas chromatography-mass spectrometry (GC-MS) is a method that combines the features of gas-liquid chromatography and mass spectrometry to identify different substances within a test sample. Applications of GC-MS include drug detection, fire investigation, environmental analysis, explosives investigation, and identification of unknown samples. GC/MS can also be used in airport security to detect substances in luggage or on human beings. Additionally, it can identify trace elements in materials that were previously thought to have disintegrated beyond identification.

Manufacturers of GC and GC/MS Equipment include: Agilent, LECO Corporation, PerkinElmer, Shimadzu, Thermo Electron Corporation, Varian, Inc. and Alpha MOS - Perichrom