Friday, November 20, 2009

Thin Layer Chromatography & pigment separation?

I have used TLC to separate plant pigments - what other biological compounds can be separated by this method though? Is its main use for the separation of proteins?


My books give information on the method but very little on the uses.





Also, does anyone know if there is any other method of separating pigments. - I don't need lots of detail - just a name so that I can look it up.





Thankyou!

Thin Layer Chromatography %26amp; pigment separation?
TLC and other chromatographic methods depend on solubility of the separating compounds and their affinity for the substrate of the chromatogram. You can separate anything that differs by having a long enough plate, and you can sometimes run a separation along one edge of a plate, and turn the plate 90 deg and run another stage of separation (often using a different solvent or solvent mixture).





It is not mainly used for separation of proteins, which are more often separated by gel electrophoresis (which separates based on charges on the proteins) or gel permeation chromatography (which separates based on size).





Pigments should be discriminated from dyes, by the way, a common error for botanists who describe all colored substances as pigments. In the wider world, pigments are generally insoluble in much of anything that leaves them intact (consider prints on clothing and the fact that dry cleaning does not remove them), while dyes are soluble in something.





In any event, if the colored material is soluble in something, be it hexane, water, THF, a chlorinated solvent, then it can be separated from other colored materials not only by TLC, but by paper chromatography and column chromatography as well.

dieffenbacbia

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