1) The document describes the procedure for separating amino acids using thin layer chromatography. 2) Key steps include coating silica gel on a plate, applying amino acid samples as spots, developing the plate in a solvent mixture, and detecting spots using ninhydrin spray to calculate Rf values. 3) Precautions are outlined such as handling reagents carefully, applying dried spots with space in between, and allowing proper solvent saturation and advancement on the plate.

1. Ms. Sadhana Gupta

3. AIM: To Separate the given sample of amino acids by thin layer
chromatography.
REQUIREMENTS –Glass chamber, silica gel G ,pipettes or graduated
cylinders , beakers , amino acid solution ,distilled water, ,stirring rod ,
tissue paper ,calcium carbonate, glass rod, tlc plate , , butanol, acetic acid,
spray bottles ,ninhydrin
PRINCIPLE-
Thin layer chromatography (TLC) depends on the separation principle.
The separation relies on the relative affinity of compounds towards both
the phases. The compounds in the mobile phase move over the surface of
the stationary phase.
The movement occurs in such a way that the compounds which have a
higher affinity to the stationary phase move slowly while the other
compounds travel fast. Therefore, the separation of the mixture is
attained. On completion of the separation process, the individual
components from the mixture appear as spots at respective levels on the
plates. Their character and nature are identified by suitable detection
techniques

4. An overview of TLC

5. PROCEDURE-
1) First step in tlc is sterilization of tlc plate in hot air oven.
2)Make a slurry of silica gel and calcium carbonate.
3)Coat the tlc plate with silica gel slurry and allow it to dry at room
temperature for 10 minute
4)Activate the TLC plate in hot air oven for 1 hr.
5)Apply sample spots with the help of capillary tube.
6)Pour the mobile phase(solvent-butanol:aceticacid:water-12:3:5) into
the TLC chamber and to maintain equal humidity, place a moistened
filter paper in the mobile phase.
7)Place the tlc plate in glass chamber containing solvent.

6. 8)Allow the sample to run on gel plate.
9)As the solvent run ¾ th remove the plate and allow it to dry for few
minutes.
10)With the help of a sprayer bottle, spray color producing reagent on gel
plates.
11)Keep the plates in hot air oven for 5-10 minutes
12)Once the spots are developed, take out the plates and dry them. The
sample spots can be observed under a UV light chamber.
13) Now calculate the RF value of samples.
Calculation -
Rf value = Distance travelled by solute
Distance travelled by solvent

7. Steps of TLC

8. Rf VALUE OF SOME AMINO ACIDS

9. RESULT - The Rf value of samples were calculated successfully
PRECAUTIONS-
•Care should be taken while handling reagents like Ninhydrin
reagent.
•Hold the TLC plates by their side. Ensure that you do not touch
the developing part of the TLC plate, because your finger prints
will also get developed causing the result to be unclear.
•Make certain that the spots applied to the plate are above the
surface of the eluting solvent
•

10. •Before applying the second spot make sure that the previously
applied spot is dried.
•Spot the components with proper space in between.
•Ensure that the chamber is saturated with the solvent vapour before
you place the TLC plate in it.
•Give enough time for the solvent to advance up the plate.
•The top of the solvent must not advance up to or beyond the edge
of the plates.