Successive Flow-injection Determination of Iron(III) and Copper(II) by Means of the Effect of Activators

A novel flow-injection (FI) photometric method has been proposed for the successive determination of iron(III) and copper(II). It is based on the effect of activators such as 1,10phenanthroline and 2,9-dimethyl-1,10-phenanthroline (neocuproine) on iron- and copper-catalyzed oxidadve coupling of p-anisidine with N,N-dimethylaniline in the presence of hydrogen peroxide. By injecting two activators, alternatively, into the Fl system, iron(III) (50 - 200 ng cm ) and copper(II) (5 -20 ng cm) can be selectively determined.