Some new sensitive procedures are introduced for the detection and determination of aniline, alpha and beta-naphthylamines, and alpha- and beta-anthramines, as well as their N-alkyl and N,N-dialkyl derivatives. The chromogens are (p-phenylazophenylazo) - aniline, -naphthylamine and -anthramine dyes. For example with N,N-dimethylaniline, the blue dication of N,N-dimethyl-p-(p-phenylazophenylazo) aniline is formed. Because of the widely differing rates of reaction naphthylamine or anthramine derivatives can be determined in the presence of aniline derivatives. Also, with the help of a masking agent a dialkylaniline can be determined in the presence of primary and secondary amines. Spot tests for aniline, naphthylamine and anthramine derivatives are described.