Magnetic solid-phase extraction based on modified magnetic meso-porous silica nanospheres for pre-concentration of trace amounts of gold/silver samples in the water and plant environment before analyzing by flame atomic absorption spectrometry

In this study, a sufficient nanostructure sorbent was produced via Fe3O4 magnetic meso-poroussilica and cetyltrimethylammonium bromide (CTAB) as surfactant sample by using a sol-gel technique. To improve the adsorption performance, the magnetic nanostructure was further optimized with bis(3-triethoxysilylpropyl)tetrasulfide. Characterization of the prepared magnetic nanoparticles adsorbents was performed by Fourier transform infrared (FT-IR), Scanning electron microscope (SEM), and Vibrating sample magnetometry (VSM). Modified magnetic nanoparticles as a new nanoparticle were prepared and used as a solid-phase extraction (SPE) adsorbent for extraction and pre-concentration of gold and silver ions from various samples. After adsorption, gold and silver ions were desorbed with the use of nitric acid followed by flame atomic absorption spectrometric determination. The linear range 2.0-400.0 ng mL(1) and 3.0-500.0 ng mL(1) with detection limit of 0.7 ng mL(1) and 0.4 ng mL(1) for gold and silver were obtained. The relative standard deviations of the method for eight replicate determination of 200 ng mL(1) of gold and silver were obtained as 1.1 and 1.3%, respectively. Furthermore, Molecular Dynamics (MD) approach used as computational method to adsorption process analyzing of porous silica and Au3+ and Ag1+ ions. Computational outputs verified laboratory analyzing and shows using porous silica matrix can be regarded as a promising system to Au3+ and Ag1+ ions adsorption process in actual cases.

Automated summary

In this study, a sufficient nanostructure sorbent was produced through sol-gel technique for the extraction and pre-concentration of gold and silver ions. The use of porous silica matrix was confirmed to be a promising system for the adsorption of Au3+ and Ag1+ ions through both experimental and computational analysis.