Thin Layer Chromatography (TLC) - Principle, procedure
Thin Layer Chromatography TLC Principle Procedure
What is Chromatography?
Chromatography means the separation of mixture of compounds. The
components travel through a stationary phase at different speeds and get
separated. The mixture is dissolved in the mobile phase and is carried through
the stationary phase.
Thin Layer chromatography is a form of planar chromatography.
The stationary phase is a TLC plate (silica gel) or alumina. The plate is run
through a solvent which is known as the mobile phase.
The principle of TLC is where mixture
components are separated between a fixed stationary phase and a liquid mobile
phase by differential affinities between the two phases. The separation is
through adsorption.
Thin-layer chromatography can be used to monitor the progress of
a reaction, identify compounds present in a given mixture, and determine the
purity of a substance.
What is
High-Performance Thin Layer Chromatography?
HPTLC (High-Performance Thin Layer Chromatography) is an advanced version
of TLC. TLC is qualitative whereas HPTLC is qualitative and quantitative. HPTLC
works on similar principles as TLC but the practice is fully automated and
GLP/USP/EP compliant. As a liquid chromatography technique, HPTLC can analyze
most non-volatile organic samples with ease.
TLC
Procedure
TLC is performed manually. Samples are applied on TLC plates. The plate
(stationary phase) is silica gel backed by Alumina or glass. The plate is run
through a solvent (Mobile phase) system for the separation of the samples.
Steps:
1. Preparation of sample and plate for the experiment. Cut the TLC plate in 10x10, 20x10 dimensions. Mark the plate with a pencil at 70mm.
2. Application of sample on TLC plate.
TLC involves manual spotting whereas HPTLC has an automatic sampler for e.g.,
CAMAG ATS 4. You can spot the samples on the plate. Mark the sample application
area with a pencil and start the spotting process.
3. Development of
plate. The plate is kept in
a solvent system such that the samples are not immersed in the mobile phase.
For this purpose, use CAMAG TTC (Twin through chambers). Observe the plate
while it is developed and remove the plate.
4. After development is finished. Air-dry the plate and
observe the separated compounds. Only the compounds observed in white light can
be seen by the naked eye. For UV active and fluorescent compounds, we need a UV chamber or CAMAG Visualizer.
5. Analysis of results requires interaction with
detected compounds. CAMAG TLC-MS coupling
uses Mass Spectrometry for the verification of the chemical structure of
analytes. Analytes can be directly sent to an MS or the results can be
collected for further analysis offline.
We
offer free HPTLC training for using CAMAG HPTLC machines in Mumbai. Call us today on 9833830898 today!
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