Question

What is the function of a locating agent?

Answer 1

Hint: As the name suggests, a locating agent is a substance or chemical which helps to separate and analyze the colorless substances.

Complete step-by-step answer:
As we know the locating agent is a chemical that is used to visualize colorless by the naked eye or with the help of UV light.
The most widely used chemical reagent is Ninhydrin which reacts with the alpha-amino group of primary amino acids to form a complex called Ruhemann's purple.
It is also used for the detection of latent fingermarks on a porous surface like paper and cardboard.
In paper chromatography, the position of solvent front marked with the help of pencil and then chromatogram is allowed to dry. After that with the help of ninhydrin chemical reagent, the solution of ninhydrin is sprayed on the chromatogram which reacts with an amino acid to visualize purple-colored compounds.
From the above figure, we can conclude that fruit juice which is taken as Control is a mixture of sucrose, glucose, polysaccharides, fructose, etc.
Sucrose, glucose, and maltose have been taken as standards, and hence by the help of a locative agent which is used to separate and analyze the colorless compounds are visible.
So, in the above diagram, by using a locative agent we can conclude that sucrose and glucose are present in fruit juice while maltose is absent.

Note: Remember, two amino acids Proline and Hydroxy-proline do not react with ninhydrin chemical reagents in the same way as the other amino acids do because these two amino acids are having an alpha-amino group that is part of the five-membered ring.