Abstract
A flotation-spectrophotometric method for the separation and determination of Fe(III) in fresh and natural water samples has been developed. The method is based on the colored complex which is formed between Fe(III) and 2- carboethoxy-1, 3-indandione sodium salt (CEIDNa). The colored 1:3 (Fe:reagent) complex is quantitatively floated with oleic acid (HOL) surfactant in the pH range 3-6. The complex in the scum is measured directly for iron at λ=490nm. Beer′s law is obeyed over the concentration range 2.8-39μg of Fe(III) in 4ml of HOL surfactant. The molar absorptivity is 0.65×104 1mol-1cm-1. The different factors affecting the flotation and determination of Fe(III) have been investigated. The determination of Fe(III) after selective flotation increases the sensitivity and eliminates the effect of foreign ions. The method was successfully applied to detect as little as 1ppb Fe in 20ml samples of natural water after flotation with HOL surfactant.
