A common method for visualizing organic compounds on a silica gel TLC plate is charring. This is usually accomplished by spraying the plate with a dilute sulfuric acid followed by heating. Organic substances appear as brown to black spots against a white background. This method is comparable in sensitivity to the visualization of UV-adsorbing compounds against a fluorescent background.Silica Get H UNIPLATES containing ammonium sulfate eliminate the need to use messy sulfuric acid for charring.
Just evaporate the developing solvent until the plate is completely dry, then heat at 150° - 200°C for 30 to 60 minutes to achiece charring.
The Analtech VPF chamber is specifically designed for this application. Other percentages of ammonium sulfate may be specified.