Fe (III) and PAN form the complex Fe(PAN)2OH which can be extracted into CHCl3. The CHCl3 extract shows absorption maxima at 550 nm and 775 nm (log E550 = 4.06, log e775 = 4.08). In the Fe(III)--PAN--Triton X-100 system, two complex species (Fe(PAN)2)+ and/or Fe(PAN)2OH may be formed. (Fe(PAN)2)+ exhibits a stronger absorption peak at 550 nm (log E550 =4.36). In this paper the effect of Triton X-100 micelles on the Fe(III)-PAN reaction has been investigated in detail. We consider that the presence of high density of ethereal oxygen chains in Triton X-100 micelles enables to concentrate hydrated Fe(III) ions and change their existing state. Moreover, the micelles not only increase the reactivity of Fe(III), but also enhance the rate of the color reaction.

Key words: MICELLE, TERNARY SYSTEM, COLOR REACTION, IRON COMPLEX, TERNARY COMPLEX, PYRIDINE AZO NAPHTHOL, NON IONIC SURFACTANTS, TRITONS