Speciation of Fe(II) and Fe(III) with chromogenic mixed reagents by principal-component regression

Simultaneous analysis of Fe(II) and Fe(III) ions has been explored by means of a two-component reagent consisting of 1,10-phenanthrolinium chloride an d salicylic acid. The linear correlation between absorbance over the whole range of wavelengths and concentrations of Fe(II) and Fe(III) separately an d in the presence of fixed amounts of each was investigated. The Principal- component regression method was applied to selective speciation of iron. Th e total relative standard error for applying the method to 10 synthetic sam ples in the concentration ranges 0.1-5 mu g/ml for Fe(II) and 0.5-20.0 mu g /ml for Fe(In) was 3.36%. (C) 1999 Academic Press.