Question

Explore the needed sources and Identify (One example) of how chromatography (e.g. TLC, HPLC) has been used to determine the chemical components of a sample.

For the example which you have chosen, remember to mention the following:

-List the chemical components identified.

- Include details of the mobile and stationary phases and the conditions used to affect the resolution of the components (e.g., flow rate, pressure, temperature,...).

Answer 1

Thin layer chromatography is a method of separation of mixtures of compounds.

one famous example of TLC is used for separation of citric acid from cyclohexene.

the first part of separation is the preparation of TLC plate. A 5*20 cm sheet is taken and a layer of Silica (SiOH) is coated on it and dried well. a spot of the mixture of citric acid and cyclohexane is put on the dried plate. Then the sample is applied to the plate. The sample should be minimum.

solvents that is used for this kind of separation is solvents like ethyl acetate or hexane could be used. the general selection of solvents is done keeping in mind the toxicity, cost, and flammability of solvents

In this separation, the stationary phase is SiOH and the mobile phase is the solution of the mixture.

In general, the separation is measured using R_f values, which is the distance traveled by the compound/ distance traveled by the solvent front.

So, the R_f value of citric acid will be lesser as compared to cyclohexene because of its strong binding with SiOH due to strong dipole-dipole interactions.