Chromatography

Is a term that encompasses a wide range of laboratory techniques that are used to separate mixtures. A mixture is dissolved, usually via a fluid dubbed ‘the mobile phase’, which in turn passes the mixture onto a different substance called the “stationary phase” — both playing unique roles in separating compounds from one another within a mixture. The various particles of the individual compounds in the mixture move around at different speeds; gradually separating to form distinct substances. The two phases are involved in a process that is known as “differential partitioning”. Each compound shares its own unique partition coefficient, which results in separation via differing interactions with the stationary phase. The process may be used as either a tool to prepare solutions, or to decipher the makeup of mixtures. It can either be used to separate entire compounds from one another, leading to a further purification of any desired material, or it can be used analytically. When used for analytics, the process involves measuring small amounts of a mixture to discover the proportions of different compounds in the makeup.

Gas chromatography — a variation of chromatography that involves the use of gas as a mobile phase — is extensively used in perfumery to unravel the compositions of fragrances.