Hi Fadia Mutiara,

For ninhydrin reagente preparation you can dissolved it in 100 mL of n-butanol plus 3 mL of glacial acetic acid. Other way is dissolved in acetone. Sprayed your TLC plate, air dried and then heated to developed color.

I hope this helps you. Kind regards

Dilute 0.5 g of ninhydrin by adding absolute alclohol to mark of measuring flask.

However, to get reaction in TLC you can use less concentrated solution, it is not so stict. I used 0.05% of this solution as a spray or for submerging of TLC plate for 1 sec. To produce colored spots, heat TLC plate in hot air (keep the plate below the hot electric towel, above hot plate or in hot air from hair drier).