Why is it important the ink dots are not submerged in the solvent chromatography?

Why is it important the ink dots are not submerged in the solvent chromatography?

It is important that the solvent level is below the line with the spots on it. As the solvent slowly travels up the paper, the different components of the ink mixtures travel at different rates and the mixtures are separated into different colored spots.

How do you ensure that the pigment origin is not immersed in solvent?

With a pencil and ruler, draw a light line across the width of the chromatography paper, about 3 cm from the bottom. This will insure that the extract, which will be streaked on this line, is not immersed in the solvent.

Why must the solvent level be below the Coloured spots in chromatography?

The solvent level has to be below the starting line of the TLC, otherwise the spots will dissolve away. Non-polar solvents will force non-polar compounds to the top of the plate, because the compounds dissolve well and do not interact with the polar stationary phase.

Why must the spots on the paper not be allowed to touch the solvent?

Do not allow the solvent front to reach the top of the plate. That may cause erroneous Rf values and may cause spots that are close together to run into each other.

What happens to the ink Spots as the chromatogram develops?

Capillary action makes the solvent travel up the paper, where it meets and dissolves the ink. The dissolved ink (the mobile phase) slowly travels up the paper (the stationary phase) and separates out into different components.

What would be the consequences of immersing the initial spots in your filter paper with your developing solvent?

If the spots were immersed they would dissolve in the solvent and be pulled down into the solvent itself. As it flows, the solutes dissolve within the moving solvent and are carried along the moving solvent.

What happened to the dots of ink after submerging it to the alcohol or solvent?

As the liquid alcohol climbs up the paper strip, it drags along the components of the ink, the more soluble components (pigments) will travel furthest on the strip, the least soluble pigments will trail behind resulting in the separation of the pigments.

What would happen if the solvent level is above the start line in chromatography?

What would happen if the solvent level is above the start line? The solvent gives extra energy to pull up the sample and the sample will also dissolve in the solvent. That’s why as precautionary measure start line should stay above the solvent in chromatography!

What has happened to the size of the starting material spots Why?

What has happened to the size of the starting material spots? The size of the starting materials spots has decreased in size. This has happened as the material has moved up the TLC.

What would happen if your initial solvent level is above the baseline ie the line where you spotted your samples on the TLC plate )?

Experiment 5: Thin Layer Chromatography and Melting Point 62 4) What would happen if your solvent level is above the level of the initial spots? Answer: The spots would dissolve into the reservoir of eluting solvent.

How are colored pigments separated in paper chromatography?

Separating Colored Pigments Paper chromatography is an effective technique for separating colored pigments from a mixture. A few drops of the mixture of colored pigments are placed on the filter paper (stationary phase) and it is then slowly submerged into a jar of solvent (mobile phase).

Why is the solvent level below the colored spots in?

Having solvent levels below the origin give a more accurate spread of colours, as the water is allowed to begin properly soaking and ink is not lost in the solution upon direct contact. Also, there is little to no motion through the paper below the solvent level and hence, the ink/dye won’t be able to travel up the chromatography paper.

How is the tip of a paper used in chromatography?

Note that chromatography solvent is highly volatile and flammable. The V-shaped tip of the paper is placed in the chromatography solvent and acts as a wick to draw the solvent up the paper, separating pigments according to their relative solubility and molecular weights.

Why is it important not to allow mixed components in chromatography?

If your sample spots dissolve in the elution solvent, mixed components from all your samples would be continuously feeding onto the whole width of your paper during the development of your chromatogram.