مشخصات پژوهش

Chromate is placed among the most important environmental pollutants that have changed into a global concern due to their toxicity and carcinogenetic properties. Chromate even in trace amounts accumulate in the body of creatures and their food cycle [1-2]. Therefore, the development of an effective method for preconcentration and determination of chromate in environmental samples is important. In this study, chitosan-based nanocomposites containing zero valance metals such as Cu, Au, Pd, and Pt were individually synthesized [3], and used as a sorbent for the solid-phase extraction and preconcentration of chromate ions from aqueous solutions prior to determination by flame atomic absorption spectrometry (FAAS). The size and morphology of the nanosorbents were characterized via x-ray diffraction analysis, scanning electron microscopy and Fourier transform infrared spectroscopy. The experimental factors affecting the extraction/ preconcentration of the analyte such as pH, amount of nanocomposite, sample volume, type and concentration of eluent and sorption and desorption time were optimized. Under the optimized experimental conditions, the calibration graph was linear in the concentration range of 0.2‒100 ng mL−1. The limit of detection and the preconcentration factor are 0.06 ng mL−1 and 100, respectively. The method was successfully applied to determine chromate in several water samples.