Webster's reagent

Webster's reagent is a solution of sodium hydroxide and ethyl alcohol used to test surfaces for the presence of TNT and Tetryl explosive compounds. Specifically Webster's reagent responds to the presence of the trinitrophenyl group. Though it is normally used in testing for explosives, presence of other nitrated organic ring compounds such as benzenes and naphthalenes will also give positive Webster reactions.

Webster's reagent stock solution is made by saturating absolute ethyl alcohol with pellets of sodium hydroxide. The stock solution is then diluted with a 9:1 ratio of absolute ethyl alcohol.