A Simple and Sensitive Approach for Determination of Iron Impurity in Military Grade Ammonium Perchlorate

In this work, we developed a simple and sensitive method for spectrophotometricdetermination of trace amounts of iron in ammonium perchlorate. The procedure is based on the reaction of Fe (II) with O-phenanthroline (O-Phen) to form colored complex ion, followed byextraction of the complex using cloud point extraction technique (CPE) in the presence of anionic surfactants sodium dodecyl sulfate (SDS) and nonionic surfactant Triton X-114 as mixed micellemediated. The complex concentrated in the surfactant rich phase was then determined at 510 nm. Some important parameters affecting reaction and extraction steps were investigated and optimized in details. Under the optimal conditions, the calibration graph for determination of iron was linear in the range of 25-700 ng mL^-1. Detection limit of the method was 10 ng mL^-1 and the relative standard deviation (RSD) for five replicate determinations of iron at 200 ng mL^-1 concentration level was 2.46 %. The proposed method was successfully applied for determination of iron impurity in military grade ammonium perchlorate. In addition, excellent agreement was observed between this proposed method and the reference method.