Difference between revisions of "Chromatography"

<onlyinclude>'''Chromatography''' enables the separation, identification, and purification of the components in a mixture. The mixture is composed of a ''mobile phase'' (fluid or gas) and a ''stationary phase''. The stationary phase is either a solid phase or a layer of a liquid adsorbed on the surface a solid support. The separation is based on the differential partitioning between the mobile and the stationary phase. <ref>{{Cite journal|title=Separation Tecniques: CHROMATOGRAPHY|year=2016|author=Ozlem Coskun|journal=Northern Clinics of Istanbul|doi=10.14744/nci.2016.32757}}</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 purification. <ref>{{Cite journal|author=Mirna González-González, Karla Mayolo-Deloisa, Marco Rito-Palomares|year=2020|title=Chapter 5 - Recent advances in antibody-based monolith chromatography for therapeutic application|journal=Elsevier|volume=|issue=Approaches to the Purification, Analysis and Characterization of Antibody-Based Therapeutics|page=105–116|doi=https://doi.org/10.1016/B978-0-08-103019-6.00005-9}}</ref><ref>{{Cite journal|title=Alternative bioseparation operations: life beyond packed-bed chromatography|year=2004-10-01|author=Todd M Przybycien, Narahari S Pujar, Landon M Steele|journal=Current Opinion in Biotechnology|volume=15|issue=5|page=469–478|doi=10.1016/j.copbio.2004.08.008}}</ref> 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 are not mutually exclusive. <ref>{{Cite book|author=K. Hostettmann|year=1998|book_title=Preparative Chromatography Techniques : Applications in Natural Product Isolation|publisher=Springer Berlin Heidelberg|place=Berlin, Heidelberg|ISBN=978-3-662-03631-0}}</ref> </onlyinclude>

To separate the components of a mixture, the mixture is dissolved in a substance, the mobile phase, which carries it through a second substance, the stationary phase. The different components of the mixture travel through the stationary phase at different speeds, causing them to separate from one another. <ref name=":1">{{Cite web|title=What is Chromatography and How Does it Work?|url=https://www.thermofisher.com/blog/ask-a-scientist/what-is-chromatography/|Author=Thermo Fischer|year=|e-pub date=|date accessed=14.02.2022}}</ref> The different molecules stay longer or shorter on the stationary phase, depending on their interactions with its surface sites. 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. A schematic illustration of the process can be seen below (illustrates column chromatography).

 

 

 

 

 

 

 

 

* Ion exchange chromatography  

** separates the components of a mixture based on their charge

* Size-exclusion chromatography