Page 132 - phytochemistry general program

Advantages of HPTLC versus conventional TLC are:

1. less diffusion and hence improved resolution.

2. Detection (determination) limits lower by a factor of 10.

3. Better cost / performance ratio.

4. Appropriate matching sample volume to 1/10 to1/5 of the volume that can be
applied on conventional plates.

5. High sample dosing quality, i.e. minimal extension of starting zone and
accurate positioning

Paper chromatography

The Practice of Paper Chromatography .1
Application. .2
.3
Development. .4
Visualization.
Evaluation and Analysis.

Solvents .1

In general, the solvent systems used in paper chromatography were based on .2
mixtures of one or more organic solvents with water. .1
.2
Papers .3

Based on filter paper, with Whatman no. 1 and no. 3

The speed of development controlled by the coarseness of the cellulose fibres and
the packing density.

Whatmann No. 4 paper has characteristics very similar to those of No. 1, but it is
about twice as fast.

Modified cellulose papers are also available.

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