مشخصات پژوهش

Cadmium (Cd) is an industrial waste or by-product, which has a great environmental concern. Cd is used in many industrial processes, such as a constituent of easily fusible alloys, soft solder, electroplating and deoxidizer in nickel plating, engraving processes, electrodes for vapor lamps, photoelectric cells, and nickel-cadmium storage batteries [1]. Although essential function of cadmium on human body is not clearly known, it may cause toxic effects even at very low doses. This toxicity could be due to a direct or an indirect interaction taking place between the metal and the biological system, as it could be the form of both extracellularly and intracellularly. Cadmium acts as inhibitor of sulphydryl enzymes and has an affinity for other ligands in cells such as hydroxyl, carboxyl, phosphatyl, cysteinyl and histidyl side chains of proteins [2]. In cancer studies, it has been reported that this metal is a mutagen in mammalian [3,4] and at concentrations higher than the maximum permissible level, it may result in prostate, renal and lung cancers [5]. In the present study, a Fe3O4@salicylic acid nanocomposite was synthesized and characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy techniques. A solid phase extraction method was developed for the separation and preconcentration of cadmium(II) ions by using the synthesized material. The method is based on the adsorption of cadmium(II) on Fe3O4@salicylic acid nanocomposite. The extracted cadmium was determined by flame atomic absorption spectrometry after desorption with a acidic sloution. The optimum experimental conditions for the cadmium assay were investigated. Under the optimized conditions, a calibration graph was linear in the range of 0.2–30 ng.mL-1 with a detection limit of 0.386 ng.mL-1. The method was successfully applied to determine cadmium in several