General: Anisaldehyde-Sulphuric acid
Dipping sol, 1 ml of anisaldehyde 2 ml conic H2SO4 in 100 ml of GAA or sprayed with 8 ml conic H2SO4 and 0.5 ml of anisaldehyde in 85ml of MeOH and 10 ml of GAA. Good for essential oil separation, phenols and terpenes. (Lots of pretty colours for all our favourite compounds.)
General: Phosphomolybdic Acid Spary
5% sol of phosphomolybdic acid in ethanol followed by a brief (5-20 min) heating at 110°C gives blue-gray spots against a yellow background. Good for many organic compounds including substituted phenols indole derivatives and essential oil components.
For Alcohols: Spray
6% ceric ammonium sulphate in 2N HNO3 will yield brown spots on yellow background.
For aldehydes and ketones: spary
Dissolve 0.4g 2,4-dinitrophenylhyrazine in 100 ml 2N HCl will yield yellow to red spots on pale orange background.
For Alkaloids: (Reagent: Iodoplatinate) Spray
(a) 5% platinic chloride in H2O (b) 10% aqueous KI Color reagent: mix 5 ml of (a) with 45 ml of (b), dilute to 100 ml with H2O will yield basic drugs yield blue or blue violet spots that turn brown yellow; addition of conc. HCl, 1 part to 10 parts of spray solution, will often increase sensitivity of reagent.
For Amines and amino acids: (reagent Indanetrione hydrate [ninhydrin]) Spray
Mix 95 parts 0.2% ninhydrin in n-butanol with 5 parts 10% acetic acid. This will yield Yellow, pink-red, or violet spots on white background.
For Barbiturates: (Reagent: s-Diphenylcarbazone Bromocresol green) Spray
0.1% reagent in 95% ethanol. Dissolve 0.04g BCG in 100 ml of ethanol; add 0.1N NaOH until blue color just appears. Will yield Purple spots. Acids: yellow spots on blue background; bases: blue spots on green background.
For Inorganic ions: (test for Hg) (Reagent: Ammonium sulfide) Spray
Saturated aqueous H2S made alkaline with NH3 Cations detected black: Ag, Hg, Co, Ni; brown: Au, Pd, Pt, Pb, Bi, Cu, V, Ti; yellow: Cd, As, Sn; yellow-orange: Sb
Thin-Layer chromatography 4th Ed Chromatographic science series vol 81
