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Oils from the skin can easily transfer from your finger to the plate if you touch the chalky side. Amino acids from these oils may show up in a developed chromatogram, ruining your experiment.
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∙ 14y ago
Anonymous
because oil from skin can cause error during the experiment
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How can you further isolate pigments on a thin layer plate in TLC experiment?
Run the mixture on the TLC plate. Find the different colored pigments. Scrape each spot and elute the pigments.
Is a TLC Plate the same as filter paper?
No. A TLC (Thin Liquid Chromatagraphy) plate is made specially. It has different Compounds to it that make it separate from filter paper. See 1st related link below for more info on TLC Plates See 2nd related link for info about filter paper
How Chromatography can be used for non colored solution?
Many organic compounds are aromatic and thus absorb ultraviolet light. Simply shine UV over your TLC plate and observe the spots. If the compound isn't UV absorbing but has a double bond, a solution of KMnO4 can be used to visibly stain the compound on the TLC plate.
Why iodine is used in thin layer chromatography?
The staining of a TLC plate with iodine vapor is among the oldest methods for the visualization of organic compounds. It is based upon the observation that iodine has a high affinity for both unsaturated and aromatic compounds. Preparation: A chamber may be assembled as follows: To 100 mL wide mouth jar (with cap) is added a piece of filter paper and few crystals of iodine. Iodine has a high vapor pressure for a solid and the chamber will rapidly become saturated with iodine vapor. Insert your TLC plate and allow it to remain within the chamber until it develops a light brown color over the entire plate. Commonly, if your compound has an affinity for iodine, it will appear as a dark brown spot on a lighter brown background. Carefully remove the TLC plate at this point and gently circle the spots with a dull pencil. The iodine will not remain on the TLC plate for long periods of time so circling these spots is necessary if one wishes to refer to these TLC's at a later date.
How do you check TLC for thio barbituric acid it wont soluble in any solvent?
Barbituric acid looks like its very polar... it should be soluble in water and acetone, at least.Visualizing it on a TLC plate is problematic because the compound is not aromatic and thus does not absorb UV. The easiest way to visualize non-UV absorbing compounds on a TLC plate is using an iodine development chamber. In a jar, mix some powdered iodine (I2) crystals* and dry silica gel. Throw in the TLC plate (after running in the appropriate solvent system), shake it a bit, and use forceps to fish it out. The iodine should oxidize the compound on the plate and it should appear as a brown dot. The iodine development chamber can be used pretty much indefinitely. Hope this helps!Do all steps in the fume hood... pure iodine is toxic.
What is the solvent front and how is its migration on the TLC plate measured?
The solvent front is the line at where the solvent moves up the TLC plate. Its migration can be measured by taking the R value of the TLC plate.
When preparing to develop a TLC plate what is the appropriate spatial relationship between the level of solvent in the developing chamber and the spots on your TLC plate?
The spots on the TLC plate should be placed about a cm from the bottom of the plate. Then solvent should then fall about half-way between these spots and the bottom of the beaker.
What will be the result of applying too much compound to a TLC plate?
Applying too much compound to the TLC plate makes it difficult for a good separation to occur. Instead, a large blot of solution tends to appear in the TLC. "It is extremely important that the spots be as small as possible and that they be applied using a 1% solution of the compounds being separated
How can you further isolate pigments on a thin layer plate in TLC experiment?
Run the mixture on the TLC plate. Find the different colored pigments. Scrape each spot and elute the pigments.
What is the component of the coating on the pre-coated TLC plate?
silica or alumina
Why KMnO4 used in TLC?
because it can make the point shown in your plate
Is a TLC Plate the same as filter paper?
No. A TLC (Thin Liquid Chromatagraphy) plate is made specially. It has different Compounds to it that make it separate from filter paper. See 1st related link below for more info on TLC Plates See 2nd related link for info about filter paper
How do you rent a car with a TLC license plate?
You have to be speaking Bangalian,Indian or a good Spanish.
What is tailing effect in TLC?
Tailing effect is an error that occurs when the spot is not allowed to dry hence leading increased diameter of the spot in a TLC plate. Nwando Ata.
Why do some compounds travel further on TLC plates than others?
it doesn't depends upon the TLC plates.. as it depends upon the solvents in which these compounds migrate.
What would happen if the spotting line and positions were marked on TLC plate with a ballpoint pen?
the marks will run as the inks will generally be soluble in the solvent used to develop the plate.
What is difference between HPLC and TLC?
TLC= In it finely solid is spread on a rigid supporting plate (stationary phase)and the mobile phase is allowed to migrate across the surface of plate by capillary action. Less efficient then HPLCHPLC= in it column are used on place of plates and the mode of separation is adsorption or partition coefficient
