| Abstract: | Reaction of 4-aminoantipyrine (4-AAP) with aromatic amines was investigated. The study showed the merits and limitations of 4-AAP as a chromogenic agent for the colorimetric determination of aromatic amies in water. Maximum colour development was reached within one minute and the colour maintained its stability for 10 min. 4-AAP is not a sensitive chromogenic reagent for the determination of chloro-, nitro-, p-substituted amines nor for polycyclic aromatic amines. Molar absorptivity of the 4-AAP-dye complexes was discussed and shown to be affected by steric hinderance and lability of the lone pair of electrons of the amino nitrogen. |
