History of Chromatography

	Revision 5 . . December 19, 2001 10:25 pm by (logged).200.130.xxx [Spelling, factual corrections, and other chromatographci techniques]
	Revision 4 . . (edit) September 14, 2001 6:58 am by Stokerm

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In chemistry, chromatography is a process for separating different components from a mixture. Usually, each component has a characteristic separation rate that can be used to identify it and thus the composition of the orignal mixture.

In chemistry, chromatography is a process for separating different components from a mixture. This is achieved by passing a sample mixture in a stream of neutral solvent through some form of material that will provide resistance by virtue of chemical interactions (NOT reactions) between the components of the sample and the material. Usually, each component has a characteristic separation rate that can be used to identify it and thus the composition of the original mixture.

Changed: 5c6

A small spot of the solution containing the sample is applied to a strip of chromatography paper about one centimetre from the base. This sample is adsorbed (bonded to the surface) of the paper. The paper is then dipped in to a suitable solvent? (such as ethanol or water) and placed in a sealed container. As the solvent rises through the paper it meets the sample mixture which starts to travel up the paper with the solvent. Different compounds in the sample mixture travel different distances according to how well they have been adsorbed on to the paper. Chromatography takes some time and the experiment is usually left to complete for some hours.

A small spot of the solution containing the sample is applied to a strip of chromatography paper about one centimetre from the base. This sample is adsorbed onto the paper. This means that the sample will contact the paper and may form interactions with it. Any substance that will react with (and thus bond to) the paper cannot be measured using this technique. The paper is then dipped in to a suitable solvent? (such as ethanol or water) and placed in a sealed container. As the solvent rises through the paper it meets the sample mixture which starts to travel up the paper with the solvent. Different compounds in the sample mixture travel different distances according to how strongly they interact with the paper. Paper chromatography takes some time and the experiment is usually left to complete for some hours.

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HPLC High performance or high pressure liquid chromatography Gel electrophoresis

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An example of the use of gas chromatography is in the study of the selectivity of Fischer-Tropsch synthesis catalysts. The outlet from this process contains a number of light gases including N2, H2, CO, CO2, H2, CH4, and Ar, as well as heavier parafinic and olefinic hydrocarbons (C2-C40). In a typical experiment, a packed column is used to separate the light gases, which are then detected with a TCD. The hydrocarbons are separted using a capillary column and detected with an FID.

An example of the use of gas chromatography is in the study of the selectivity of Fischer-Tropsch synthesis catalysts. The outlet from this process contains a number of light gases including N2, H2, CO, CO2, H2, CH4, and Ar, as well as heavier parafinic and olefinic hydrocarbons (C2-C40). In a typical experiment, a packed column is used to separate the light gases, which are then detected with a TCD. The hydrocarbons are separated using a capillary column and detected with an FID.