Visualization Characters for TLC

发布日期：2016-06-10 07:37 来源：网络作者：网络浏览次数：

Reagent	Works well for	Colors	Notes
Iodine	Unsaturated and aromatic compounds	Brown spots	Not permanent
Sulfuric acid	General stain	Brown or black spots
Chromic acid	For difficult to stain compounds	Black spots
UV light	Compounds with extended conjugation like aromatic compounds	Pink on light green background	Only visible under UV light
Cerium sulfate	Good general stain, very well for alkaloids
Ferric chloride	Phenols	Purple
Ninhydrin	Amino acids, amines	Purple
2,4-Dinitrophenylhydrazine	Aldehydes, ketones	Yellow/orange	also called “DNP”
Vanillin	Good general stain, very well for hydroxyl or carbonyl compounds	Colors vary
Potassium permanganate	Works well for all compounds that can be oxidized	Yellow on purple Yellow or light brown on purple	at r.t. for alkenes and alkynes upon heating for alcohols, amines, sulfides
Bromocresol Green	Carboxylic acids (pK_a<5)	Yellow spot on blue background
Cerium molybdate (CAM, ‘Hanessian’s Stain’, Ceric staining)	Good general stain, very well with polyhydroxylated and carbonyl compounds	Blue or green spot	Upon heating, very sensitive!
p-Anisaldehyde	Good general stain, particularly sensitive towards nucleophiles	Varying colors on light pink plate upon heating	Does not work with alkenes, alkynes or aromatic system unless functional groups are present
Phosphomolybdic acid (PMA)	Very sensitive	Dark green spot on light green plate	Sensitivity can be enhanced by use of cobalt(II) chloride
Ehrlich’s Reagent (Dimethylaminobenzaldehyde)	Indoles, amines	Pink or red-violet
Dragendorff-Munier Stain	Amines even the ones that are low in reactivity	Various colors

The spots on the TLC plate should be circled (marked) to have a permanent record how far the compound traveled on the plate. A sketch of the developed plate should be placed in your lab notebook. A picture (cell phone) could not hurt either.

相关阅读：