Spectrophotometric Assay of Iron (II) in Pharmaceutical Formulation Using Alizarin Red Sulphonate Reagent

Abstract A rapid, sensitive and simple spectrophotometric method was developed for the determination of iron (II). The method was based on the reaction of iron (II) with alizarin red sulphonate reagent to form a brown chelating complex in an aqueous solution. The absorbance of the chelating complex was measured at 566 nm with a molar absorptivity of 7.8 x 103 l.mol-1.cm-1. The chelating complex conforms to Beer's law over the range (0.5-5) g.ml-1. the average recovery% was 100.06% and precision (RSD) was found to be less than 1%. The method was successfully employed for assay of iron (II) in pharmaceutical formulations (tablets and capsules). The results have been compared with British pharmacopoeia method.