TLC stains for amines

 

First of all if it has got an aryl then it should be UV active otherwise you can use Ninhydrin stain. It works best for amino acids, amines, amino sugars.  Spray the plate with a solution of 0.2g ninhydrin in 100ml ethanol and heat until spots (reddish) appear.  You can achieve better sensitivity if you add 3 ml of acetic acid to the above solution. You can also add 1 g of cadmium acetate (for detection of heterocyclic amines) or 1ml of pyridine (for detection of peptides) in combination with AcOH.

Alternatively you can spray the plate with a solution of tert-Bu-hypochlorite in CCl4 and then dry it to get rid of all the hypocholite (otherwise whole plate stains black and it will be difficult to visualize) and the spray it with a m,m'-dimethoxybenzidine.  Amines and amides which have free NH give a black spot on a white back ground.  Another stain which you can use is Ehrlich’s reagent (very good for amines, indoles, pyrrolizidine alkaloids).  This reagent is nothing but a combination of p-Dimethylaminobenzaldehyde and hydrochloric acid reagent just spray the plate with a solution of 1 g of p-dimethylbenzaldehyde in 75 ml of MeOH and 50 ml of concentrated HCl and gently heat the plates.

Vanillin reagent will also detect amines and amino acids.  6 g Vanillin,1.5 ml Conc. sulfuric acid, 95 ml 96% Ethanol.  Dip the plates and heat it for the spots to appear.  Some PIP stain (potassium iodoplatinate stain) 1 g hexachloroplatinate (alfa), 20 g KI, 592 ml H₂O, 54 ml conc. HCl.  You can heat the plate high for spots to appear (not so good!) leave the plate at rt the spots appear very good but this is again a slow process.