Do you really know Chromatography?
Chromatography, the collective term for a set of laboratory techniques for the separation of mixtures, is a kind of separation and analysis method. It has found wide applications in the field of Analytical Chemistry, Organic chemistry and Biochemistry.
History
It was in the year of 1900 that chromatography was first employed in Russia by the Italian-born scientistss Mikhail Tsvet. In the first decade of the 20th century, he continued to work with chromatography, especially for the separation of plant pigments such as chlorophyll, carotenes, and xanthophylls. It’s just because those components have different colors, green, orange, and yellow, the technique was given the name. During the 1930s and 1940s, the development of new types of chromatography endowed the technique more applications in many separation processes.
Later on, the chromatography technique developed substantially as a result of the work of Archer John Porter Martin and Richard Laurence Millington Synge. It was during this time, the principles and basic techniques of partition chromatography were established. The work of those scientists pushed forward the development of a few chromatographic methods: paper chromatography, gas chromatography, and liquid chromatography. Since then, the technology has developed rapidly in the following years.
Classification
Affinity Chromatography
Affinity chromatography, based on selective non-covalent interaction between an analyte and specific molecules, is very specific, but not very robust. Generally, it is more frequently used in biochemistry in purification of proteins bound to tags. Affinity chromatography often utilizes a biomolecule’s affinity for a metal (Zn, Cu, Fe, etc.). Columns are often manually prepared. Traditional affinity columns are used as a preparative step to flush out unwanted biomolecules.
Ion Exchange Chromatography
Ion Exchange Chromatography, also referred as ion chromatography, utilizes an ion exchange mechanism to separate analytes based on their respective charges. Ion exchange chromatography uses a charged stationary phase to separate charged compounds including anions, cations, amino acids, peptides, and proteins. Ion exchange chromatography is commonly used to purify proteins using FPLC.
Gel Filtration Chromatography
Gel Filtration Chromatography, also known as gel permeation chromatography (GPC) or size-exclusion chromatography, separates molecules based on their sizes (or more accurately, according to their hydrodynamic diameter or hydrodynamic volume). It is generally a low-resolution chromatography technique and thus it is often reserved for the final “polishing” step of a purification. Moreover, it is also useful for determining the tertiary structure and quaternary structure of purified proteins, particularly because it can be carried out under native solution conditions.
Source: https://en.wikipedia.org/wiki/Chromatography