Editing Chromatography (section)

{{Short description|Set of laboratory techniques for separation of mixtures}}
{{for|the album by Second Person|Chromatography (album)}}
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{{Continuum mechanics}}
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[[File:Chromatography of chlorophyll - Step 7.jpg|upright=0.4|thumb|Thin-layer chromatography is used to separate components of a plant extract, illustrating the experiment with plant pigments which gave chromatography its name]]

In [[chemical analysis]], '''chromatography''' is a [[laboratory technique]] for the [[Separation process|separation]] of a [[mixture]] into its components. The mixture is dissolved in a fluid solvent (gas or liquid) called the ''mobile phase'', which carries it through a system (a column, a capillary tube, a plate, or a sheet) on which a material called the ''stationary phase'' is fixed. Because the different constituents of the mixture tend to have different affinities for the stationary phase and are retained for different lengths of time depending on their interactions with its surface sites, the constituents travel at different apparent velocities in the mobile fluid, causing them to separate. The separation is based on the differential partitioning between the mobile and the stationary phases. Subtle differences in a compound's [[partition coefficient]] result in differential retention on the stationary phase and thus affect the separation.<ref>{{cite book |last1=McMurry |first1=John |title=Organic chemistry: with biological applications|url=https://archive.org/details/fundamentalsorga00mcmu|url-access=limited|date=2011|publisher=Brooks/Cole|location=Belmont, CA|isbn=9780495391470|pages=[https://archive.org/details/fundamentalsorga00mcmu/page/n412 395]|edition=2nd}}</ref>

Chromatography may be ''preparative'' or ''analytical''. The purpose of preparative chromatography is to separate the components of a mixture for later use, and is thus a form of [[List of purification methods in chemistry|purification]].<ref name="González-González-2020">{{Citation|last1=González-González|first1=Mirna|title=Chapter 5 - Recent advances in antibody-based monolith chromatography for therapeutic applications|date=2020-01-01|work=Approaches to the Purification, Analysis and Characterization of Antibody-Based Therapeutics|pages=105–116|editor-last=Matte|editor-first=Allan|publisher=Elsevier|language=en|doi=10.1016/b978-0-08-103019-6.00005-9|isbn=978-0-08-103019-6|last2=Mayolo-Deloisa|first2=Karla|last3=Rito-Palomares|first3=Marco|s2cid=226450210 |doi-access=free}}</ref><ref>Alternative bioseparation operations: life beyond packed-bed chromatography

T.M. Przybycien, N.S. Pujar and L.M. Steele

Curr Opin Biotechnol, 15 (5) (2004), pp. 469-478</ref> This process is associated with higher costs due to its mode of production.<ref>{{cite journal|last1=Ongkudon|first1=Clarence M.|last2=Kansil|first2=Tamar|last3=Wong|first3=Charlotte|date=2014|title=Challenges and strategies in the preparation of large-volume polymer-based monolithic chromatography adsorbents|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/jssc.201300995|journal=Journal of Separation Science|language=en|volume=37|issue=5|pages=455–464|doi=10.1002/jssc.201300995|pmid=24376196 |issn=1615-9314|url-access=subscription}}</ref><ref name="González-González-2020"/> Analytical chromatography is done normally with smaller amounts of material and is for establishing the presence or measuring the relative proportions of analytes in a mixture. The two types are not mutually exclusive.<ref>{{cite book| vauthors = Hostettmann K, Marston A, Hostettmann M |title=Preparative Chromatography Techniques Applications in Natural Product Isolation|date=1998|publisher=Springer Berlin Heidelberg|location=Berlin, Heidelberg|isbn=9783662036310|page=50|edition=Second}}</ref>