Chromatography is a continuously evolving scientific discipline or field "studying the formation, change, movement, and separation of multiple concentration zones of chemical compounds (analytes or particles) of the studied sample in a flow of mobile phase relative to selective influence of one or a number of solid/liquid stationary phases or sorbents." Components requiring separation join with the mobile phase — a gas or a liquid, for example — and pass through an immobile or stationary phase — a liquid or a solid. The components sorb or accumulate either in the stationary phase or at the border of where the phases interface, moving at different speeds based on sorptivity and forming a regular distribution. This distribution is measured with the help of a chromatograph, spectrophotometer, mass spectrometer, and/or other detector and output as a chromatogram, typically in graph form as a function of elution time.
Chromatographic separations were originally confined to colored plant pigments and dyes, but they quickly expanded to include colorless substances. Today, chromatographic methodology has expanded greatly with technological and scientific innovation, with a method for almost any type of analyte or particulate matter in the most minute of quantity.
Chromatography has numerous associated methods, dependent on the process-specific movement and type of mobile phase:
|Methods of chromatography|
|Mobility or equilibria||Phase||Chromatography type|
|→||Liquid||Tswett (column), paper, thin-layer|
|→||Supercritical medium||Supercritical fluid|
|↔||Sorbent liquid||Hypersorption, countercurrent, denuder|
|↓↑||Adsorption||Liquid-solid (gel), gas-solid, supercritical fluid-solid|
|↓↑||Chemisorption||Ion exchange, affinity, complex-forming|
|↓↑||Absorption (partition)||Liquid-liquid, gas-liquid|
|↓↑||Physical field||Field-flow fractionation|
|Equilibrium (isotherm)||Techniques, channel||Hyphenated techniques|
|Non-linear||Displacement, flat bed||Combined with spectral methods|
(Note: Arrows in the table indicate the movement of the analyte-containing mobile phase.)
- Analytical chromatography
- Chromatography data system
- Fast protein liquid chromatography
- Gas chromatography
- Gel permeation chromatography
- High-performance liquid chromatography
- Ion chromatography
- Preparative high-performance liquid chromatography
- Supercritical fluid chromatography
- Ultra high-performance liquid chromatography
- Ettre, Leslie S.; Zlatkis, Albert, ed. (1979). "75 Years of Chromatography: A Historical Dialogue". Journal of Chromatography Library - Volume 17. Elsevier. pp. 501. ISBN 0080858171. http://books.google.com/books?id=tdrFTHQ3e64C.
- Wixom, Robert L.; Gehrke, Charles W., ed. (2011). Chromatography: A Science of Discovery. John Wiley & Sons. pp. 410. ISBN 1118060296. http://books.google.com/books?id=pKKoOCsytBMC.
- Wixom, Robert L. (ed); Gehrke, Charles W. (ed.); Berezkin, Viktor G.; Janak, Jaroslav (2011). "Chapter 1: Chromatography - A New Discipline of Science". Chromatography: A Science of Discovery. John Wiley & Sons. pp. 1–13. ISBN 1118060296. http://books.google.com/books?id=pKKoOCsytBMC.
- Sharma, B.K. (2007). "Chapter 1: Chromatography". Chromatography. Krishna Prakashan Media. pp. C1–C20. ISBN 8185842795. http://books.google.com/books?id=HkLq-fCAxg0C.