Stains for TLC Plates
This chart describes the most frequently used TLC visualization methods (also called stains) in alphabetical order.
Name | Visualization of... | Conversion / Selectivity (%) | Comments |
---|---|---|---|
p-Anisaldehyde #1 |
Universal Stain |
Prepare stain as follows
|
Visualization Colors
Appropriate Storage
|
N.B.: Tends to be insensitive to alkenes, alkynes and aromatic compounds unless other functional groups are present. |
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p-Anisaldehyde #2 |
Acronycine |
Prepare stain as follows
|
Visualization Colors
Appropriate Storage
|
Bromocresol Green |
Acidic groups (pKa < 5) |
Prepare stain as follows
Tip: Add the base slowly at the end until the solution turns pale blue. |
Visualization Colors
Appropriate Storage
Heating NOT required |
Cerium Molybdate |
Universal Stain |
Prepare stain as follows
|
Visualization Colors
Appropriate Storage
|
N.B.: Highly sensitive stain; very low concentration of product may appear as a significant impurity. |
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Cerium Sulfate |
Difficultly stainable compounds |
Prepare stain as follows
|
Visualization Colors
|
Chromic Acid |
Difficultly stainable compounds |
Prepare stain as follows
|
Visualization Colors
|
Cobalt Chloride |
Universal stain Used in conjunction with PMA when this one is not effective enough |
Prepare stain as follows
Tip: simply dip PMA treated plate in CoCl2 solution. |
Visualization Colors
Heating NOT required |
p-Dimethylamino- |
Amines |
Prepare stain as follows
|
Visualization Colors
|
2,4-Dinitrophenyl-hydrazine |
Aldehydes |
Prepare stain as follows
|
Visualization Colors
DO NOT HEAT dipped plate |
Dragendorff Reagent |
Nitrogenous Compounds Phenols |
Prepare stain as follows Solution A
Solution B
Tip: mix 5 mL of each solution A and B to a solution of 20 mL of acetic acid in 70 mL of water. |
Visualization Colors
Appropriate Storage
Stain Shelf-Life
DO NOT HEAT dipped plate |
Ferric Chloride |
Phenols |
Prepare stain as follows
|
Visualization Colors
|
Iodine |
Unsaturated & |
Prepare stain as follows
|
Visualization Colors
|
N.B.: iodine stain can be removed by heating. |
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Morin Hydrate |
Universal stain |
Prepare stain as follows
Tip: by weight. |
Visualization Colors
|
Ninhydrin |
Amino Acids |
Prepare stain as follows
|
Visualization Colors
|
Phosphomolybdic Acid |
Universal stain |
Prepare stain as follows
|
Visualization Colors
|
N.B.: Can be used for detection of alcohols, amines, sulfides and mercaptans groups when gently heated. |
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Potassium Permanganate (KMNO4) |
Olefins |
Prepare stain as follows
|
Visualization Colors
|
Vanillin |
Universal stain |
Prepare stain as follows
|
Visualization Colors
|
(N.B.: Shaded lines refer to “universal stains”. Occasionally, spots can be seen more clearly from glass side with glass backed TLC plate. Otherwise mentioned, stains are long-term stable when stored in a tightly-closed container to prevent solvent evaporation. “BG” stands for “background”.) |