A Nano-Composite Based on Fe3O4@Styrene-Maleic Anhydride Copolymer as a Magnetic Sorbent for Preconcentration of Silver(I) Ion

A magnetic nano-composite based on modified styren-maleic anhydride copolymer and Fe3O4 nano-particles was introduced as a new sorbent for solid-phase extraction and preconcentration of trace levels of silver ion from aqueous solutions. The size and morphology of the nano-sorbent were characterized via X-ray diffraction analysis, scanning electron microscopy and Fourier transform infrared spectroscopy. Following its desorption with hydrochloric acid, silver was detected by flame atomic absorption spectrometry. Different variables affecting the separation/pre-concentration of the silver ion were optimized. Under the optimized conditions, the calibration graph was linear in the 1–200 µg L–1 concentration range, with a correlation coefficient of 0.9991. The limit of detection and relative standard deviation for six replicate determinations at a silver ion level of 100 µg L–1 were 0.3 µg L–1 and 1.1 %, respectively. The preconcentration factor and adsorption capacity of the sorbent for silver ion were 100 and 78.2 mg g–1, respectively. The accuracy of the method was confirmed by analyzing the certified reference material NIST SRM 1566b. The method was successfully applied to determine silver ion in water samples and in radiology films, and satisfactory recoveries were obtained in the range of 96.8–99.6 % for the spiked samples.