Spectrophotometric determination of iron as phenylfluorone complex sensitized with Triton X-100

Abstract

The effect of some surfactants and protective colloids on the absorbance of the iron(III)-phenylfluorone complex has been investigated. The binary complex formed at pH 9.0 show a molar absorptivity of 7.5×104 l · mol−1 · cm−1 at 530 nm. In the presence of 2% Triton X-100, at the same pH, the molar absorptivity of the sensitized complex was 1.19×105 l · mo−1 · cm−1 at 555 nm. Full colour development of the sensitized complex occurred within 25 min and Beer's law was followed up to 0.53 ppm of iron. The molar ratio and continuous variation methods indicated a 1∶3 metal-ligand ratio for the sensitized complex. The effect of various amounts of different ions has been studied under the experimental conditions and some masking agents were recommended. The method has been applied to the determination of iron in copper and nickel metals and some non-ferrous alloys.