Spectrophotometric Determination of Fe(Ⅲ) in Aluminum and Aluminum Alloys with Alizarin Yellow GG as Color Reagent

Chromogenic reaction of alizarin yellow GG with ferric ion in an ammoniacal buffer of pH 8.0-10.0 and in the presence of CPB was studied by spectrophotometry.A red complex with mole ratio of 3 to 1 between alizarin yellow GG and Fe(Ⅲ) was formed,having its absorption maximum at the wavelength of 470 nm,at where the apparent molar absorptivity was found to be 5.281×104L·mol-1·cm-1.Beer′s law was held in the range within 1.0 mg·L-1 of Fe(Ⅲ).The proposed method was used in the determination of iron in aluminum and aluminum alloys,with the results found in consistency with the known values,and giving values of RSD′s (n=8) less than 3%.