It has been found that certain insecticides, rodenticides, herbicides and fungicides on solid state supports give fluorescence when sprayed with solutions containing 2-diphenylacetyl-1,3-indandione-1-imine derivatives. Compounds that give high fluorescence include DDT, Chlordane, Heptachlor, Toxaphene, Methoxychlor, Diazinon, Carbophenothion, DDVP, Warfarin, phenoxyacetic acid, methyl l-naphthaleneacetate, Chloranil, Dichlone, and 1,4,5,6,7,7-hexachloro-N-(ethylmercuri)-5-norbornene-2,3-dicarboximide. The effect is based on fluorescence enhancement of the 2-diphenylacetyl-1,3-indandione-l-imine derivatives as a result of molecular complexation with the compound detected.