Dinitrotoluene and trinitrotoluene with potassium hydroxide form a compound with characteristic red-violet color.
Scale, 50 mL laboratory beaker, glass storage bottles, a spot plate (Fig. 1).
A few milligrams of sample is dissolved in a drop of acetone and then mixed with a drop of strong potassium hydroxide solution. A characteristic red color (Fig. 2) indicates di- and tri-nitroaromatic compounds.