A new spray reagent replacing sulphuric acid in thin-layer chromatography
Tadeusz Zimiński, Edward Borowski
Journal of Chromatography A
Volume 23, 1966, Pages 480-482
"The latter reagent is prepared by dissolving 20 g of ammonium sulphate in
100ml water and adding 4 ml sulphuric acid (d = 1.84)."
Aluminium, silica gel hot plate ~400 C. Used for all non-volatile organic compounds.